This lecture was part of The Evolution Institute’s Risky Adolescent Behavior Workshop. You can see all the videos from the workshop at The Evolution Institute’s Viddler Page.

The original article, Impact of diet in shaping gut microbiota revealed by a comparative study in children from Europe (urban Florence) and rural Africa (Boulkiemde province, Burkina Faso), by Carlotta De Filippo and colleagues, is open access on the Proceedings of the National Academy of Sciences website, so you should definitely surf over there if you find this interesting.

De Filippo and colleagues discuss the microbiome, the ‘complex consortium of trillions of microbes, whose collective genomes contain at least 100 times as many genes as our own eukaryote genome’ (see also Gill et al. 2006). This enormous, varied ecosystem in the gut, a symbiotic community, supplements human metabolic capabilities, provides a first line of defense against pathogens, modulates gastrointestinal development and even informs the configuration of the immune system (paraphrased from De Filippo et al. 2010).

Different gut ecologies brought about both by environmental factors and by food production techniques, dietary preferences, and even food handling practices are one way that human groups might inadvertently induce biological variation in our species, a subtle culture-biology link through the populations in our gastrointestinal tracts. Now De Filippo and colleagues has gone out and actually demonstrated this variation empirically, using high-throughput 16S rDNA sequencing and biochemical analyses of fecal microbiota.

What’s on YOUR plate?

In Burkina Faso, children’s diets after weening were ‘low in fat and animal protein and rich in starch, fiber, and plant polysaccharides, and predominantly vegetarian.’ Diet was primarily composed of cereals (millet grain, sorghum), legumes (black-eyed peas), and vegetables, providing ample amounts of nonanimal protein, carbohydrate and dietary fibre (children in Burkina Faso were getting more than three times the fibre eaten by the comparative population from Italy).

The children in Burkina Faso got very little animal protein, primarily a bit of chicken from time to time and, during the rainy season, termites (also interesting because of their role in chimpanzee diets, but we’ll be back to the termites because they’re the punchline of the article).

In contrast, the Italian children, after being weaned at an earlier age, on average, were taking in a diet much higher in animal protein, sugar, starch, and fat, with lower fiber (in part due to greater food processing) and much greater energy.

Startlingly, the children, 2- to 6-years-old, in Burkina Faso got 996 kcal/day compared to the Italian children who were eating 1,512.7 kcal/day; even prior to the age of 2, children in Italy were taking in an average of 60% more calories than Italian children! (This also harkens back to our discussion of what makes WEIRD populations truly odd.)

The community inside them

The faecal samples from children in Burkina Faso especially differed from the Italian subjects because of the presence of Prevotella, Xylanibacter (Bacteroidetes), Treponema (Spirochaetes), and Butyrivibrio; all appeared in the African samples but were not found in the Italian. The researchers hypothesize that these distinctive bacterial genera might help to extract energy from the polysaccharides in the children’s heavier fiber diet. Theses bacteria are capable of fermenting cellulose and xylan through a number of carbohydrate-active enzymes, producing anti-inflammatory effects at the same time.

From the Science News article by Dickey:

Children from Burkina Faso, who ate millet grain, sorghum wheat, legumes and vegetables, had high numbers of bacteria that digest plant fibers. Also found in the guts of termites, these bacteria break down fibers that humans typically can’t. The bacteria make short-chain fatty acids that give people energy and protect them from inflammatory gut diseases such as Crohn’s disease and inflammatory bowel disorder.

Burkina Faso’s children also had decreased numbers of diarrhea-causing bacteria compared with children from Italy. That finding surprised the team, because the African children often drank water polluted with such bacteria.

The diminished diversity of microbiota in the human gut is especially interesting because some theorists have pointed to this dietary-provoked transformation, together with increasing hygiene and anti-bacterial technologies in human environments, as possible contributors to an upsurge in rates of allergies, auto-immune disorders and inflammatory bowel diseases (see, for example, Strachan 1989). Recent research has suggested a relationship between ecological imbalances in gut microbiota and obesity, and inflammatory conditions in the bowel have been directly linked to changes in gut microflora. For example, bacterial species correlated with a high-fat, high-sugar diet promote obesity in gnotobiotic mice (Turnbaugh et al. 2009). In other words, the diet can have a twin-pronged attack on our ability to maintain low body weight, as it provides both higher calories as well as a shift in microbiota to a population that promotes obesity.

The team led by De Filippo compared the diversity of microbial life in the fecal samples from both locations, finding that the African samples, by several measures, had greater diversity and richness of symbiotic life.

Exposure to the large variety of environmental microbes associated with a high-fiber diet could increase the potentially beneficial bacterial genomes, enriching the microbiome. Reduction in microbial richness is possibly one of the undesirable effects of globalization and of eating generic, nutrient-rich, uncontaminated foods. Both in the Western world and in developing countries diets rich in fat, protein, and sugar, together with reduced intake of unabsorbable fibers, are associated with a rapid increase in the incidence of noninfectious intestinal diseases. The potential protective effects of the diet on bowel disorders was first described by Burkitt [1973] who, working in Africa in the 1960s, noticed the remarkable absence of non-infectious colonic diseases in Africans consuming a traditional diet rich in fiber.

The fact that the youngest children in both populations had similar microbial profiles in their GI system suggests that diet primarily is effecting the difference between the two populations; while both groups are still breastfeeding, they are more similar, only diverging later when they start to eat their distinctive cultural diets.

Horizontal transfer of microbial life

The short piece in Science News makes clearer, in my admittedly non-specialist reading, an interesting little wrinkle in the story of diet affecting gut microbiota: the horizontal transfer of microbes from our food to our own guts. As Gwyneth Dickey writes:

A termite a day may keep the doctor away. African children who eat a high-fiber diet (and the occasional wood-digesting insect) have gut bacteria that help them digest plant fibers and protect them from diarrhea and inflammatory disease, a new study finds.

What I’m struck by here, and I’m not sure if this is Dickey’s interpretation or something one of the researchers said, is the suggestion that some of the microbes most able to turn whole grains into short chain fatty acids might be colonizing the large intestines of children in Burkina Faso through the rainy season practice of dining upon termites! (She quotes co-author Duccio Cavalieri warning, ‘We’re not saying you should eat termites,’ but it’s unclear where the original suggestion might have come from – Dickey or the research team.) I have absolutely no idea if this is actually possible, but there is the case of microbes being transferred from food to Japanese individuals who dine on some forms of algae (see Hehemann et al. 2010).

The more I think about this possibility – that we might pick up symbiotic microfauna by eating the guts of other animals – the more I find it both weirdly fantastic and simultaneously plausible. After all, what living organism is more likely to survive the digestion process to colonize the human gut than a microbe that’s already adapted to the gastro-intestinal tract of another animal?

But if it’s happening, we have a case where children are picking up microbes that will live in their guts and help them to digest dense fibrous foods by eating termites. What could be a better example of a kind of dietary ‘contagious magic’ than eating an animal and gaining some of its distinctive powers of digestion?! Eating termites might make it possible for your body to digest ‘woody’ food sources.

Further reading:

It’s not the gut, but I’ve written about the microbial life on the skin back in The human ‘super-organism’.

Image:
Gut population cartoon originally from Yakult.

References:

Burkitt, D. P. 1973. Epidemiology of large bowel disease: The role of fibre. Proceedings of the Nutrition Society 32:145–149. doi:10.1079/PNS19730032

De Filippo, Carlotta, Duccio Cavalieria, Monica Di Paolab, Matteo Ramazzottic, Jean Baptiste Poulletd, Sebastien Massartd, Silvia Collinib, Giuseppe Pieraccini, and Paolo Lionetti. 2010. Impact of diet in shaping gut microbiota revealed by a comparative study in children from Europe and rural Africa. Proceedings of the National Academy of Sciences. Published online August 2, 2010. doi: 10.1073/pnas.1005963107.

Gill, Steven R., Mihai Pop, Robert T. DeBoy, Paul B. Eckburg, Peter J. Turnbaugh, Buck S. Samuel, Jeffrey I. Gordon, David A. Relman, Claire M. Fraser-Liggett, and Karen E. Nelson. 2006. Metagenomic analysis of the human distal gut microbiome. Science 312:1355–1359. doi: 10.1126/science.1124234

Hehemann, J. H., G. Correc, T. Barbeyron, W. Helbert, M. Czjzek, and G. Michel. 2010. Transfer of carbohydrate-active enzymes from marine bacteria to Japanese gut microbiota. Nature 464:908–912. doi:10.1038/nature08937

Strachan, David P. 1989. Hay fever, hygiene, and household size. British Medical Journal 299:1259–1260. doi:10.1136/bmj.299.6710.1259

Turnbaugh, Peter J., Vanessa K. Ridaura, Jeremiah J. Faith, Federico E. Rey, Rob Knight and Jeffrey I. Gordon. 2009. The effect of diet on the human gut microbiome: A metagenomic analysis in humanized gnotobiotic mice. Science Translation Medicine 1:6ra14. doi: 10.1126/scitranslmed.3000322

I didn’t get to stay for the whole conference because I was running around doing preparation things for the Australian Anthropological Society Conference that we held in December. Nevertheless, I saw some really good papers, and some of the others are especially interesting for those of us interested in neuroanthropology. Please peruse the whole list, but for a discussion of cultural variation in cognition, of special interest might be: Nian Liu’s Tuesday, Threesday, Foursday: Chinese names for the days of the week facilitate Chinese children’s temporal reasoning, Zhengdao Ye’s Eating and drinking in Mandarin and Shanghainese: A lexical-conceptual analysis, Collaborative remembering: When can remembering with others be beneficial? by Celia B. Harris, Paul G. Keil, John Sutton and Amanda J. Barnier, and Expanding expertise: Investigating a musician’s experience of music performance by Andrew Geeves, Doris McIlwain, and John Sutton.

I also like the look of Evaluation of a model of expert decision making in air traffic control, by Stefan Lehmann and colleagues, but I haven’t had the time to really read it (and won’t get time for a few days). Ben Jeffares’ paper was excellent in presentation, but I haven’t yet checked out the written version yet: The evolution of technical competence: strategic and economic thinking.

My paper from the conference, Cultural variation in elite athletes: Does elite cognitive-perceptual skill always converge?, is available as a pdf. I have to admit, it’s a shallower paper than I usually like to present, but I had to cover a LOT of turf, and it’s primarily a proposal for a research program, reviewing the neurological and behavioural places where I expect we might find the clearest evidence of cultural difference in neural dynamics. I’ll take the liberty of reposting the abstract:

Anthropologists have not participated extensively in the cognitive science synthesis for a host of reasons, including internal conflicts in the discipline and profound reservations about the ways that cultural differences have been modeled in psychology, neuroscience, and other contributors to cognitive science. This paper proposes a skills-based model for culture that overcomes some of the problems inherent in the treatment of culture as shared information. Athletes offer excellent cases studies for how skill acquisition, like enculturation, affects the human nervous system. In addition, cultural differences in playing styles of the same sport, such as distinctive ways of playing rugby, demonstrate how varying solution strategies to similar athletic problems produce distinctive skill profiles.

I’d love to hear any responses to the piece. I don’t usually present in cognitive science, as I’m more comfortable in my home discipline of anthropology, working from a pretty solid base of anthropology into the border of brain-culture research, so I’d be interested to learn what scholars situated more confidently in cognitive science think of the piece.

It had a great line-up: Steven Rose, Douglas Hofstader, Maxine Sheet-Johnson, Timothy Ingold, and a host of Danish scholars whose work we can now all expore. The three days of the conference each addressed a different theme: Brain Plasticity, Awareness and Intentionality, and Beyond Dualisms.

You can read the Introductory Statement on the conference. Here’s one paragraph from the end:

Neuroscience seems to have learned from its critics. Reductive and neurocentric positions have to give way to the ideas that the plastic brain is capable of learning for life, and that both bodily movement as well as social activity leaves clearly formed traces in the development of the brain. Whenever we pray, learn to ride a bicycle, or read a book, the brain changes. The brain is not destiny. Are there no limits, human and neurobiological, to how much we can learn and to the extent that upbringing might effect changes in the brain?

The best thing is that you can get the videos from all the talks. So here is Steven Rose on The Future of the Brain – Promises and Perils of the Neurosciences (preceed by an intro to the conference), Jesper Morgensen on Any Limits to Neuroplasticity?, and Tim Ingold on The Social Brain.

You can access the entire program and all the videos at the Great Expectations conference website.

By Greg Downey and Daniel Lende

Neuroanthropology places the brain and nervous system at the center of discussions about human nature, recognizing that much of what makes us distinctive inheres in the size, specialization, and dynamic openness of the human nervous system. By starting with neural physiology and its variability, neuroanthropology situates itself from the beginning in the interaction of nature and culture, the inextricable interweaving of developmental unfolding and evolutionary endowment.

Our brain and nervous system are our cultural organs. While virtually all parts of the human body—skeleton, muscles, joints, guts—bear the stamp of our behavioral variety, our nervous system is especially immature at birth, our brain disproportionately small in relation to its adult size and disproportionately susceptible to cultural sculpting. Compared to other mammals, our first year of life finds our brain developing as if in utero, immersed in language, social interaction, and the material world when other species are still shielded by their mother’s body from this outside world. This immersion means that our ideas about ourselves and how we want to raise our children affect the environmental niche in which our nervous system unfolds, influencing gene expression and developmental processes to the cellular level.

Increasingly, neuroscientists are finding evidence of functional differences in brain activity and architecture between cultural groups, occupations, and individuals with different skill sets. The implication for neuroanthropology is obvious: forms of enculturation, social norms, training regimens, ritual, and patterns of experience shape how our brains work and are structured. But the predominant reason that culture becomes embodied, even though many anthropologists overlook it, is that neuroanatomy inherently makes experience material. Without material change in the brain, learning, memory, maturation, and even trauma could not happen. Neural systems adapt through long-term refinement and remodeling, which leads to deep enculturation. Through systematic change in the nervous system, the human body learns to orchestrate itself as well as it eventually does. Cultural concepts and meanings become anatomy.

Although every animal’s nervous system is open to the world, the human nervous system is especially adept at projecting mental constructs onto the world, transforming the environment into a sociocognitive niche that scaffolds and extends the brain’s abilities. This niche is constructed through social relationships, physical environments, ritual patterns, and symbolic constructs that shape behavior and ideas, create divisions, and pattern lives. Thus, our brains become encultured through reciprocal processes of externalization and internalization, where we use the material world to think and act even as that world shapes our cognitive capacities, sensory systems, and response patterns.

Our ability to learn and remember, our sophisticated skills, our facility with symbolic systems, and our robust self control all mean that the capacity for culture is, in large part, bought with neurological coin. This dynamic infolding of an encultured nervous system happens over developmental time, through the capacity of individuals to internalize both experience and community-generated tools, and then to share thoughts, meanings and accomplishments. Thus, a central principle of neuroanthropology is that it is a mistake to designate a single cause or to apportion credit for specialized skills (individual or species-wide) to one factor for what is actually a complex set of processes.

Most academic research implicitly or explicitly utilizes a reductive cause-effect approach; in popular understandings of the brain, the tendency to single out causal factors is even more prevalent. Rather than one set of genes or an overarching system of meaning, humans’ capacity for abstract thought emerges equally from social and individual sources, built of public symbol, evolutionary endowment, social scaffolding, and private neurological achievements. In neuroanthropology, the goal is not simply to juxtapose a simplistic critique against a one-side initial account, but to attempt a much more holistic, synthetic exploration of how various elements in these dynamic relations interact to produce cognitive functions.

Neuroanthropology: Areas of Application

Neuroanthropology has four clear roles: (1) understanding the interaction of brain and culture and its implication for our understanding of mind, behavior, and self; (2) examining the role of the nervous system in the creation of social structures; (3) providing empirical and critical inquiry into the interplay of neuroscience and ideologies about the brain; and (4) using neuroanthropology to provide novel syntheses and advances in human science theory.

The interaction of brain and culture is neuroanthropology’s core dynamic, exploring the synthesis of nature and nurture and cutting through idealized views of biological mechanisms and cultural symbols. Using social and cultural neuroscience in combination with psychological anthropology and cultural psychology, neuroanthropology builds in-depth analyses of mind, behavior and self based on an understanding of both neurological function and ethnographic reality. This research creates robust analyses of specific neural-cultural phenomena, recognizing that each may demonstrate a distinctive dynamic; for example, neuroanthropological investigation reworks our understanding of human capacities like balance (often assumed to be something innate), studies how practices like meditation shape and piggyback upon neural functioning, and examines the interactive nature of pathologies like addiction and autism.

Neuroanthropology has profound implications for our understanding of how societies become socially structured. Inequality works through the brain and body, involving mechanisms like stress, learning environments, the loss of neuroplasticity, the impact of toxins, educational opportunities (or their absence) and other factors that negatively shape development. Neuroanthropology can play a fundamental role in documenting these effects and in linking them to the social, political and cultural factors that negatively impact on the brain. At the same time, technological and pharmacological interventions are playing an increasing role in managing behavioral disorders, often with great profit for companies, while cognitive enhancement drugs, brain-computer interfaces, and neuro-engineering will surely be used in ways that create new separations between haves and have-nots. Finally, societal appeals to “hard-wired” differences remain a standard approach by people in positions of power to maintain racial, gender, sexual and other inequalities; a deeper understanding of the complex origins and unfolding of key neural and physiological differences undermines accounts that assume these distinctions are inescapable. At the same time, neuroanthropology points to new ways to think about how people become talented and ways to understand intelligence, resiliency, social relations and other factors that shape success in life.

In societies across the globe, the brain now acts as a central metaphor, a substitute for self, a way to explain mental health, a short-hand for why people are different. In reaction, critical approaches have looked at the interpretation and use of brain imagery, psychoactive pharmaceuticals, public presentations of neuroscience research, and related social phenomena. Meanwhile, the pace of neuroscience research, and innovations in associated technologies, has been breathtaking. One aim for neuroanthropology is to make sense of these three related but often conflicting factors in ways that provide grounded research and critical insight into what the realities of brain and self actually are. Neuroanthropology will play a central role in mediating between the claims of different sides with the expertise gained from empiricism as well as the theoretical and critical framework gained from the combination of neuroscience and anthropology. This aspect of neuroanthropology is an absolute necessity given the convergence of these three recent historical phenomena – accelerating research, social reworkings, and intellectual interrogation of both.

Neuroanthropology makes direct contributions to theory development. At the most basic level, it provides a broad umbrella to integrate concepts across academic fields. Embodiment, for example, is an idea explored from basic neuroscience, psychology and cognitive linguistics to anthropology and philosophy. Neuroanthropology provides the conceptual and methodological tools to work through what we mean by such a broad-ranging idea.

Neuroanthropology also has direct implications for anthropology and neuroscience. It demonstrates the necessity of theorizing culture and human experience in ways that are not ignorant of or wholly inconsistent with discoveries about human cognition from brain sciences. Rather than broad-based concepts like habitus or cognitive structure, neuroanthropology focuses on how social and cultural phenomena actually achieve the impact they have on people in material terms. Rather than assuming structural inequality is basic to all societies, neuroanthropologists ask how inequality differentiates people and what we might do about that.

Similarly, on the neurological side, the principal theories of brain development, neural architecture and function remain tied to a biological view of proximate mechanisms and evolutionary origins. Yet it is abundantly clear that many neurological capacities, such as language or skills, do not appear without immersion in culture. Neuroanthropology highlights how that immersion matters to the brain’s construction and function. For example, neuroanthropology can take a basic idea like Hebbian learning — “what fires together, wires together” — and examine how social and cultural processes shape the timing, exposure, and strength of activity, such that the coordinated action of brain systems emerges through cultural dynamics. Neuroanthropology opens up a vibrant new space for thinking about how and why brains work the ways they do.

Neuroscientists and Anthropologists as Partners

By placing the focus on the individual’s nervous system and its relation to the world, neuroanthropology asks challenging questions of scale and depth for both neuroscientists and anthropologists, demanding both groups stretch beyond accustomed frames. For neuroscientists, seriously considering human diversity may require changes in research methods, in such basic processes as averaging and amalgamating imaging data, removing outlying data points (some of the most interesting individuals), and in finding test subjects. It can help cultural neuroimaging researchers to develop a much more sophisticated understanding about what results of comparative brain scan of Asians and Western Europeans might mean and why seeing doesn’t always translate into cultural believing. Thus, neuroanthropology offers to neuroscientists more sophisticated ways of thinking about neural environment, based upon over a century of debate about the nature of cultural variation and how to conceptualize patterns of behavior.

The same thought and subtlety that goes into understanding the relations among parts of the brain and body can be extended to consider how elements of the cultural and social environment are tied into specific brain functions, illuminating some of the specific ways that mind can become extended through cultural leveraging. That is, simply adding ‘culture’ as a single population variable fails to really illuminate the dynamic, inconsistent processes through which neurological potential is channeled by specific cultural institutions or practices. Because the nervous system is embedded within the world, shot through with the environment down to its cellular structure, integrative models of its development must include interacting elements from both inside and outside of the skin.

Although brain scientists have reached out to other interlocutors, we believe that anthropology is an especially strong potential partner. The influence of culture, social interaction and behavior patterns are immediate and susceptible to direct research, often more so than evolutionary theories about brain architecture origin. In addition, ethnographic research offers concrete evidence of how social and cultural dimensions of the environment might affect cognitive function, and illustrates the range of neuroplasticity in developmental outcomes well beyond what most experimental protocols consider. Anthropologists explore naturally-occurring experiments in which the nervous system is developed over a lifetime in diverging directions.

For anthropologists, neuroanthropology entails a return to integrative research after decades in which many biological and cultural anthropologists have seen each other as the primary opposition. The anthropological study of the nervous system calls on anthropologists to make good on our promises of holism. Psychological anthropologists have called for a greater focus on elements of neuroanthropology — affect, memory, neural-based models of cognition, biocultural integration — but a wholesale shift requires anthropologists to maintain a simultaneous consideration of what may have previously been apportioned to different specialties in the field. The nervous system inherently spans boundaries between specialized knowledge of such areas as evolution, child development, physiology, perception, phenomenology, behavioral research, biology and culture. Although some researchers might pull back from considering biology out of a fear of reductionism, the nervous system resists obstinately any simplistic explanation, throwing up counter-examples such as varying degrees of mental modularity, cognitive heterogeneity, and complex mixtures of neuroplasticity and innate endowments shaped by evolution.

With rare exceptions, anthropologists have not participated extensively in the growing movement toward cultural neuroscience. The time is ripe for this engagement: brain scientists are no longer content to just treat cultural difference as a demographic variable, and anthropologists are no longer so afraid of ‘universalizing’ or ‘psychologizing’ that they cannot get involved in this expanding area of research. Anthropologists offer to brain scientists more robust accounts of enculturation to explain observable differences in brain function, a range of resources for extending neurological accounts beyond the individual human organism. Neuroscience research offers to anthropology a more nuanced way of linking universal human tendencies and cultural particularity, and in grounding one foot of the holistic study of human subjects firmly in biology.

Neuroanthropology is a sustained effort, not to mine brain sciences opportunistically, but to engage continually in interrogating the brain sciences to enrich holistic anthropology, while also contributing to the unfolding of cultural neuroscience. Neuroanthropologists will have to keep abreast of new research techniques and findings, and to be willing to modify, expand, or shed outright our theories if they are unsupported by data. Anthropology has tended to be a theoretically heterodox field, producing more than its fair share of paradigms for understanding human social life, so neuroanthropologists should have abundant resources on which to draw, as long as we are willing to range far and wide for our intellectual frameworks, including into the past paradigms of relevant fields.

Unlike some people working in this area, the organizers of this conference do not believe that only one research method will contribute to neuroanthropology, nor that this emerging field of thought will become dominated by a single account of how the brain functions. The brain itself is baroque, fashioned over evolutionary time out of a host of modules and functional units that are still incompletely integrated. Every type of neurological activity does not obey the same rules, nor are they equally susceptible (or immune) to self-reflection and conscious thought. Some cognitive capacities are characterized by deeply-ingrained stereotypical species-general responses; other functions are remarkably plastic, even susceptible to substantial revision and conscious redirection. No one simple theory can explain how every system works so we should recognize that enculturation will vary even among the regions and networks within the brain. If an account of one system remains consistent with its functioning while defying expectations arising from other systems, this is as likely to be a product of the brain’s heterogeneity as it is a reflection of differences in research methods or approaches.

Enough over-arching theories have foundered on human neural heterogeneity to offer ample warning: neuroanthropological theory will have to be partial and incremental rather than overly generalizing and prematurely sweeping. That is, no single enculturation process affects all brain areas equally, so no single account of the relation between brain and culture is likely to prove compelling in all cases. We propose an evidence-based theoretical eclecticism, recognizing that some of our disagreements are likely to arise from the fact that we theorize from different case studies in neural acculturation.

We also see neuroanthropology’s role as a constructive contributor to integrative brain science, not just policing its borders or offering constant critical scrutiny. Certainly, critique has its place, but without helping to produce better paradigms or suggestions for improvement, critique simply leaves conscientious researchers without positive alternatives to the practices that warrant criticism. Full engagement must include constructive proposals for improving both brain science and anthropological research.

Thinking through Human Problems

Neuroanthropology stakes out a new space for research. In examining the interaction of biology and culture, neuroanthropology considers how activities, contexts, and experiences are crucial to forming what it means to be human and how humans are similar and different around the world. Rather than conceiving of subjectivity as a text to be interpreted and the brain as composed of hard-wired circuits or innate modules beholden to selfish genes and evolutionary algorithms, neuroanthropology posits that subjectivity and the brain meet in the things that people do and say and the ways we interact with one another and the environment. Thus, it does not limit itself to psychology, which has a predominant focus on internal states, often separate from the body, physical activity, and the specifics of interaction with cultural environments. Moreover, neuroanthropology does not limit itself to Western notions of mind, self or consciousness, which can dominate discussions in some academic settings.

The inherent variety among different brain systems means that conscious reflection and experience-based accounts have a crucial relation to many of the phenomena we study. Experience-based ethnographic descriptions can offer valuable insights into brain functioning. At times these descriptions can help illuminate the influence of context and experience; at other times, neuroanthropological accounts may highlight the limits of conscious awareness and demonstrate the self-deceptions inherent in some kinds of neurological functioning. For this reason, neuroanthropology brings an ethnographic sensibility to brain research, including a willingness to take into consideration native theories of thought and individuals’ accounts of their own experience. Thus, careful ethnographic research, in-depth interviews, and the analysis of indigenous worldviews will always be central to the neuroanthropological synthesis

At the same, researchers must explore automization, endocrinology, emotion, perception, and other neural systems that contribute to patterns of variation but are not entirely susceptible to reflection. For example, practices of child rearing and early formative experiences are clearly influenced by cultural ideologies about how children should be nurtured, but many of the organic mechanisms through which these ideologies take hold of individuals and affect their long-term development may be unknown, even invisible to the participants.

For a long time, anthropologists have focused on culture as a system of symbolic associations, public signs, or shared meanings. But from the perspective of the nervous system, patterns of variation among different groups may include significant non-conscious, non-symbolic traits, such as patterns of behavior, automatized response, skills, and perceptual biases. This neuroanthropological framing opens more space for considering why all types of cognition may not operate in identical fashion, and how non-cognitive forms of neural enculturation might influence thought and action. Given this type of functioning, neuroanthropologists will have to return to an older notion of ‘culture,’ one that considers capabilities, habits and other forms of collective action (and not just meaning). While it can prove useful to speak principally of ‘culture’ as shared representations, we also must recognize that ‘cultural variation’ will include other sorts of patterned, shared conditionings of the nervous system.

For this reason subjects’-eye-view accounts are critical to neuroanthropology in a way that they might not be to other cognitive theorists. First, we recognize that theories about how the mind works or what it needs are themselves part of the developmental environment in which the brain is formed. Even if these ideas don’t accurately represent actual neural function, they do influence the brain-culture system, and can have an impact on the way the brain works even if that is in a way utterly unintended by those who hold the ideas. That is, whether indigenous theories of thought are accurate, they are part of the ecology of brain conditioning.

Second, consciousness itself is part of complex neural systems, adding degrees of self-regulation, restraint, learning, monitoring, cuing, and a host of other capacities. How people understand and experience their own thought is part and parcel of neural activities, although not necessarily an all-encompassing awareness or even the most important part of that function. Yet most of our cultural and neural functioning is submerged, only accessible to consciousness with extraordinary effort and special techniques, if it is accessible at all. Thus, research techniques should focus on capturing both our conscious awareness of why we do what we do and the inherent processes that shape the flow and outcome of that doing.

Third, we would point out that cognitive science itself is a hybrid, composed of researchers working in a range of fields from philosophy and psychology to neurophysiology, artificial intelligence and robotics. Different types of neurological functioning are susceptible to different types of research and demand varying degrees of analytical flexibility, including modeling and simulation. Although neuroimaging has made remarkable strides in recent decades, even its practitioners recognize that it must combine with other sorts of fields and data in order to draw robust conclusions beyond the narrow confines of experimental protocols.

Fourth, cultural resources like subtle differences in language may support distinctive phenomenological insights into the human nervous system. That is, other cultures may notice things about the human nervous system that our own communities have not observed, thematized, or codified. For example, the cognitive neuroscience of highly skilled communities or specialists who refine certain brain functions, such as meditation, perceptual skills, or high performance cognitive abilities in areas like mental calculation, recall or spatial navigation, have demonstrated marked empirical differences in brain function in imaging studies. But something similar might happen as well in indigenous folk theories of thinking or other neural functions, and we lose a vital resource if we do not ask ourselves how ethnographic communities come to their own ideas about the mind and experience.

When anthropologists and other ethnographers have engaged with cognitive science, they have made remarkable contributions. Neuroscientists with anthropological inclinations have made similar important advances. But overall the traffic has been too little in both directions, and the contributions made have been piece-meal rather than systemic or sustained. The brain sciences need the research and insights that anthropologists have developed in order to seriously explore the wide variation in human cognitive and neural functioning. Anthropology must move beyond critique and engage with these fields in a constructive mode in order to answer basic questions about culture, inequality, and human difference. Together, we can help construct the frameworks that allow the best of diverse research on the brain and human nature to be shared across disciplinary lines.

The potential gains are enormous: a robust account of brains in the wild, an understanding of how we come to possess our distinctive capacities and the degree to which these might be malleable across our entire species. The applications of this sort of research are myriad in diverse areas such as education, cross-cultural communication, developmental psychology, design, therapy, and information technology, to name just a few. But the first step is the one taken here – by coming together, we can achieve significant advances in understanding how our very humanity relies on the intricate interplay of brain and culture.

Greg Downey is senior lecturer in anthropology at Macquarie University. Daniel Lende is assistant professor of anthropology at the University of Notre Dame.

This essay on Why Neuroanthropology? Why Now? is the conference statement for The Encultured Brain: Building Interdisciplinary Collaborations for the Future of Neuroanthropology.

by Drew Matott and Drew Cameron

Jake was fond of saying that even though he had become dumber, he wasn’t quite dumb enough. He knew that the improvised explosive device (IED) in Iraq had mangled his body, brain and self.

Jake (a pseudonym) lost 30 IQ points due to Traumatic Brain Injury (TBI) from that IED blast. According to the military, he was still smart enough to function and hold down a job, so they didn’t plan to include TBI in his disability rating.

He fought them on this, just as he fought them on the decision not to amputate his leg. After countless surgeries and rehabilitation techniques, his leg was almost useless, allowing him maybe 30 minutes of use before it started rebelling against its reconstructed form. The pain that caused was excruciating; he simply couldn’t use it more.

Eventually Jake won his battle to lose his leg. It was the best thing that happened to him during the year I got to know him while doing my dissertation fieldwork at Walter Reed Army Medical Center in Washington, D.C. (yes, that Walter Reed).

Dealing with, or writing about, TBI is rarely as clear as an amputation. The same is true of TBI’s nearly constant companion, Post Traumatic Stress Disorder (PTSD). TBI and PTSD are not injuries that you can see, unlike a lost leg. Despite the high numbers of TBI and PTSD cases from Iraq and Afghanistan, the relationship of these conditions to more obvious forms of combat trauma remains a fraught one: Witness the debate about PTSD and the Purple Heart.

Most people think that the Purple Heart, that most iconic of military honors, is awarded to American military members injured in combat. As with most issues military, it is not quite that simple.

In 2008, after months of consultation, the decision was made not to award the Purple Heart to those suffering from PTSD because, in part, the medal “recognizes those individuals wounded to a degree that requires treatment by a medical officer, in action with the enemy or as the result of enemy action where the intended effect of a specific enemy action is to kill or injure the service member.” PTSD doesn’t count.

Though the decision was officially framed in rather bureaucratic terms, the debate which surrounded it raises much deeper issues about the nature of trauma. Thinking through these issues has led me to think about the Cartesian split between the (internal) mind and the (external) body and the nature of trauma inside and out.

From one perspective, TBI is trauma itself. It is the physical result of the brain being banged around inside the skull or otherwise damaged. But its symptoms – being ‘dumb’, acting out, short term memory loss – are the kinds of things we normally associate with an interior self.

To complicate matters further, in the soldiers I worked with, TBI was accompanied by visible injuries, sometimes to the head, sustained during the same event. Jake, for example, had nearly his whole scalp peeled from his skull along with his helmet. But this actually had nothing to do with his TBI, which was caused by the force of the IED blast itself.

This gives TBI a slightly strange status on the physical-mental continuum that you can see in things like the RAND study on Invisible Wounds which consistently pairs mental health issues and TBI, thus linking them together while still setting TBI apart. So does all of this make TBI any more or less bodily? Any more or less interior?

PTSD, on the other hand, is the reaction to trauma. It is linked to the memory of, and psychological response to, a physical event or threatened physical event. This would seem to put it squarely on the mental end of the continuum. Yet most recent innovations in the treatment of PTSD have focused on the bio-chemistry and physicality of the brain.

Such a ‘physical’ approach has its benefits. For example, most of the soldiers I worked with were highly resistant to talk and other ‘interior’ kinds of therapy while they relished the idea of treatments which work on the mind through the body. Medication does that, but so do things like Virtual Reality Exposure therapy. (For more background on the causes and treatments for PTSD in soldiers, see Erin Finley’s terrific posts here and here).

And while we tend to think of PTSD as a psychological reaction to a particular traumatic event, in my fieldwork it was more often the result of a whole slew of experiences which had very much to do with the body, sights, sounds, smells, and corporeal feelings of discomfort, pain, heat, exhaustion, sleeplessness. These same bodily sensations constitute in part the experience of PTSD, meaning that while diagnoses or theorizations of PTSD may focus on the mind, the subjective experience of it is very much in the body.

Even when we recognize that the mind and the body are connected, as we do in the realms of psychopharmacology, most people generally subordinate one to the other and deny their unity. We do that by relying on Cartesian dualism, by splitting the self into body and mind and then mapping the two parts onto the outside and inside. By marking the bodily self as the province of medicine and the mind as the province of psychiatry, we deny a more complete understanding of the subjective experience of trauma.

Jake’s amputated leg, his short term memory loss, his insomnia, his problems with linear thought, his 30 missing IQ points, his headaches, these are all part of his transformed self and way of being in the world. Though it may be required, in certain clinical settings, to typologize these pieces of him, to call them symptoms and assign them to various qualitative and quantitative categories, as anthropologists we are relatively free of these paradigmatic constraints. Our discipline is essentially an empathetic one and when working with people who have endured certain kinds of trauma, we ought to do our best to maintain the integrity of their experience. After all, haven’t they been ripped apart enough?

Zoë H. Wool is a doctoral candidate in anthropology at the University of Toronto. You can reach her at zoe.wool@utoronto.ca

The role of race in human genetics and biomedical research is among the most contested issues in science. Much debate centers on the relative importance of genetic versus sociocultural factors in explaining racial inequalities in health. However, few studies integrate genetic and sociocultural data to test competing explanations directly.

Note how that fits so well into the points just made in Nature/Nurture: Slash to the Rescue. But Gravlee, Non and Mulligan don’t just say we need to overcome the nature vs. nurture dichotomy, they do research that bridges it and even better, test ideas on both sides: “We draw on ethnographic, epidemiologic, and genetic data collected in southeastern Puerto Rico to isolate two distinct variables for which race is often used as a proxy: genetic ancestry versus social classification.”

This type of collaborative research can be crucial to getting the data to answer complicated questions. Connie Mulligan and Lance Gravlee deserve credit for taking the time to discuss how to bring together their respective approaches before going out to do research. In this case, the data come down more on the nurture (or social) side. As they write:

Our preliminary results provide the most direct evidence to date that previously reported associations between genetic ancestry and health may be attributable to sociocultural factors related to race and racism, rather than to functional genetic differences between racially defined groups.

Before someone gets all hot and bothered, Lance has also shown how to bring nurture back to nature. In Gravlee’s recent paper, How Race Becomes Biology: Embodiment of Social Inequality (pdf), he gives us following: “Drawing on recent developments in neighboring disciplines, I present a model for explaining how racial inequality becomes embodied – literally – in the biological well-being of racialized groups and individuals. This model requires a shift in the way we articulate the critique of race as bad biology.”

In the PLoS paper, Lance, Amy and Connie are aiming squarely at the use of race in medicine, where it has become common in some circles to use racial classification as a proxy for genetics. Basically this research destroys the proxy notion, since social classification turns out to be a better predictor of blood pressure than genetic ancestry.

Yet the research also highlights that genetics does play a role, just not in the broad way we normally think (nature as cause). Specifically the data revealed an association between systolic blood pressure and a specific polymorphism, α2C adrenergic receptor deletion, only when social classification and socioeconomic status were included in the analysis.

This research also reveals social complexity. As the figure from the PLoS paper above indicates, there are interactions between racial classification, socioeconomic status, and systolic blood pressure in Puerto Rico. The basic conclusion is the opposite of what many of us might expect – those perceived as darker (negro) have higher blood pressure when in a higher social class. Conversely, those with lighter skin have higher blood pressure with lower SES. These results can be related to complex social dynamics. Darker colored individuals likely face more racial discrimination when in a higher SES because Puerto Rico is still a racially divided country, with wealth and status running lighter to darker. Here is the PLoS paper:

The pattern we observe is consistent with the hypothesis that social classification based on color entails differential exposure to social stressors related to blood pressure. In particular, there is ethnographic evidence that Puerto Ricans perceived as negro, as compared to trigueño or blanco, may encounter more frequent frustrating interactions in high-SES settings due to institutional and interpersonal discrimination.

Put in a broader sense, this paper points to the need to actively consider social inequality and discrimination as causes of health problem, something the “race as genetics” idea completely fails to do. Along with colleagues, Gravlee has made this point forcefully in a previous paper, Race and Ethnicity in Public Health Research: Models to Explain Health Disparities.

At the end of the PLoS paper Lance, Amy and Connie highlight an important direction for future research: “Although our measure of social classification improves on existing approaches, further research is needed to assess how well it approximates the ascription of color in everyday social interaction. Future research could build on our measurement approach by testing whether non-biological markers of social status (e.g., hair style, dress, speech) influence social classification.”

I’d also encourage Lance and his colleagues to look more closely at perceived discrimination, that this is also a crucial mediator of how race ends up driving biology. It’s not just consensus about racial classification, but how an individual person reacts to that. This point is made broadly by Robert Sampson when he discusses perceptions of disorder as an important force behind disparity. Building an ethnographically informed measure of subjective discrimination could add an important link in the pathway from social inequality to changes in blood pressure.

But this paper also challenged me. What is particularly good is that Lance builds on previous research that established how social classification according to “color” trumps actual skin pigmentation in establishing race and in impacting health. Now he and Connie have taken that a step further to get the data and test both biological and cultural ideas.

So this morning I am thinking more seriously how I could better examine the nature/nurture debate around addiction (quite similar in form to the race and health debate – biology does it; no, it’s inequality). How can studying sin become a closer look at how people get engaged in destructive behaviors, and which factors (working together, I’d say) are most important? Because right now the biologists are going to say, well it’s dopamine (or glutamate or whatever neurotransmitter is the flavor of the day) and the anthropologists are going to say, well it’s meaning. I’m still stuck at saying “holistic interactionism” (as Pinker would put it) rather than showing more concretely how the two come together and then relating both to genetics and to symbolism.

Lance Gravlee, Amy Non and Connie Mulligan have already taken that next concrete step. Kudos!

For more on Lance Gravlee’s work, please visit his website. For more on Connie Mulligan’s work, here’s her UF website.

For those looking for coverage of some of the paper’s highlights, you can check out the University of Florida’s press release, Socio-cultural, genetic data work together to reveal health disparities.

Gene Expression also provides a useful summary with Hypertension, Race, Class and Puerto Rico, including a comment by Lance clarifying a couple points.

And here’s the link for the PLoS full text of Genetic Ancestry, Social Classification, and Racial Inequalities in Blood Pressure in Southeastern Puerto Rico.

1984 Women's 3000 meter

Although Budd had been setting the pace, she faded to seventh in the end and was booed by the partisan LA audience (Decker would later say that she was inexperienced at running in a pack and, as the trailing runner, was responsible for their contact). Maricica Puica of Romania won the event, and Britain’s Wendy Sly took the silver in a final that was seared into my memory by the televised replays of a stricken Mary Decker, hip injured from her fall, shattered and crying on the infield.

In all of the drama, one of the things that left the greatest impression on me as a high school student and sometime athlete was the simple fact that Zola Budd ran without shoes, an almost unimaginable idea to me at the time. Budd was one of a handful of famous barefoot runners, including Abebe Bikila, the Ethiopian marathoner who won his first Olympic gold in 1960 without shoes, Tegla Loroupe, the Kenyan women’s running legend and multiple world record holder, and Ken Bob Saxton, aka ‘Barefoot Ken Bob,’ a marathoner and guru to the shoeless.

I’ve been thinking about barefoot running for a while, oddly enough since I started writing about bare-knuckle punching in no-holds-barred fighting (or ‘mixed martial arts’ like the Ultimate Fighting Championship in its early days). Barefoot running, even more than bare-knuckle boxing, reveals the ways that very simple technologies, if used consistently enough, become part of the developmental niche of the human body, shaping the way that our bones, muscles, tissues, and nervous system develop.

Although this post is not strictly neuroanthropology, I thought I might share some of what I’m working on, in part because I’m interested to hear any feedback people have. In particular, this will focus on how hard it is to sort out what’s ‘natural’ when activity patterns, incredibly variable, are necessary ingredients in the development of biological systems. But also, as it will become clearer in the post, the ways that our nervous system adapt to different situations, such as having heavily padded feet or being barefoot when we run, illustrates well how even unconscious training is a form of phenotypic, non-genetic, adaptation.

Before I go any further, though, if you have anything to say in response to this, I would love to read it. This is my first attempt to put down some thoughts that will be in a chapter of an upcoming book…

I was sparked to finally put this down and post it by an item in Wired Science: ‘To Run Better, Start by Ditching Your Nikes,’ by Dylan Tweeny. (See below for a number of other recent articles online.) Tweeny writes:

Strong evidence shows that thickly cushioned running shoes have done nothing to prevent injury in the 30-odd years since Nike founder Bill Bowerman invented them, researchers say. Some smaller, earlier studies suggest that running in shoes may increase the risk of ankle sprains, plantar fasciitis and other injuries. Runners who wear cheap running shoes have fewer injuries than those wearing expensive trainers. Meanwhile, injuries plague 20 to 80 percent of regular runners every year.

The article shares quotes by a number of barefoot running advocates who argue strongly that running in minimalist shoes, or unshod, reduces the likelihood of injury: ‘After all,’ Tweeny writes in a discussion of the work of Daniel Lieberman, a professor of human evolutionary biology at Harvard University, ‘we evolved without shoes.’

In the passage, Tweeny refers to a study published in the British Journal of Sports Medicine (Clinghan et al. 2008) that found cheap running shoes correlated with better long-term health outcomes than more expensive footwear. Runners who used more expensive running shoes had a pretty shocking 123% higher rate of injury than those in less expensive shoes (see Robbins and Waked 1997). The Robbins and Waked (1997) study directly focused on the relation between deceptive shoe advertising and the force of barefoot subjects’ footfall when they came down on a surface designed to look like shoe padding. Led to believe that the surface was protecting them, people changed their running style in ways that increased impact.

The rate of injuries among runners, including the relatively consistent injury rate despite ‘improvements’ in shoe technology, make some observers suspicious that shoes might be causing, rather than protecting against, injury, even if the link is indirect through shifts in technique or even the population that can participate. Ross Tucker and Anthony Dugas of The Science of Sport point out that there are, in fact, many possible explanations for changes in injury rates – or changing reasons why rates remain constant – such as the demographic factor that many runners in the 1990s might be in significantly worse physical condition than runners in the 1970s as the hobby spread to less-fit individuals. But Tucker and Dugas, too, conclude that certain types of running shoes may not be good for all distance runners, a conclusion supported by a range of research (see, e.g., Richards, Magin and Callister 2009).

In a review of research on barefoot running and training, Michael Wharburton (2001) suggests that running and walking without shoes may decrease acute injury rates from accidents (sprains), diminish chronic injuries from repeated shock (among them, plantar fasciitis), and increase movement economy, because additional weight on the feet is harder to carry while running than weight elsewhere (see Divert et al. 2008). Wharburton asks in his conclusion why more runners don’t opt to run barefoot, suggesting it might be fear of puncture wounds, thermal problems, or even misperceptions about the dangers. He does allow that in inclement weather and with certain biomechanical problems, shoes would be essential to compensate for lower limb issues (see Burge 2001 for reservations about Wharburton’s advice, especially with a range of medical conditions that she details – highly recommended if you’re considering running barefoot but have some pre-existing foot problems or other health issues).

A number of groups advocate barefoot running for a host of reasons: health, injury prevention, greater sensation, enjoyment, and overall well-being (e.g., Driscoll 2004; Robbins and Gouw 1990). Especially prominent websites include
Barefoot Ken Bob, Barefoot Ted, and evangelist Barefoot Rick (who’s all about saving soles… I know, ‘ouch.’ Sorry, Rick.). A recent book, Born to Run: A Hidden Tribe, Superathletes, and the Greatest Race the World Has Never Seen, by Christopher McDougall specifically discusses the Tarahumara Indians, who run extraordinarily long races through rough country in sandals or barefoot. The interest in barefoot running and the possibility that some types of shoes may be increasing problems for devoted runners has produced a spate of articles (see the list at the end of this article for a few).

As Ross and Jonathan have written of their own series of posts on running shoes, the topic is extremely controversial, provoking heated discussion, enthusiastic discussion, and strong opinions, no doubt because ‘shoes, more than any other topic, touches runners where it counts – their feet! And, unfortunately, their wallets, for it’s still the largest expense a runner incurs for the sport.’

They suggest that the trend in shoe design is toward very neutral (not motion controlling), cushioned shoes that are lighter than previous generations of footwear. In addition, virtually every shoe company has produced a ‘barefoot’ shoe design, minimalist footwear designed to mimic the dynamics of barefoot running. The Vibram Five Fingers, a glove-like light shoe, for example, was named by Time Magazine one of the Inventions of the Year in 2007. Vibram is even recruiting research subjects for Prof. Lieberman’s research on barefoot running dynamics.

I should point out that I have no personal interest in any shoe company, or in criticizing any shoe company. I run with shoes (when I run), but I do like to run barefoot on the beach whenever I can. And my border collie, Louie, is a fanatic about barefoot running…

Shoes, padding and running technique

The padding in running shoes changes the way that we run, even though we may be completely unconscious that our gait has compensated for the change in the biomechanical properties of the feet produced by footgear (see Divert et al. 2005; but c.f. De Wit et al. 2000).

Robbins and Gouw (1991) argue that, with padded shoes, ‘a perceptual illusion is created whereby perceived impact is lower than actual impact, which results in inadequate impact-moderating behavior and consequent injury.’ That is, the perception of impact that is diminished by modern ‘protection’ causes runners to neglect basic biomechanical adaptations to decrease stress on the legs, such as shortening the stride, changing the point of footfall, or increasing bend in the knees slightly.

Joseph Froncioni, an orthopedic surgeon, describes at length the way that shoes change the dynamics of running. Although the assertion that barefoot runners come down on the ball of the foot is controversial (some proponents and scholars argue that barefoot runners come down on the middle-outside of the foot; see Ross Tucker’s post on this debate), quite a bit of his description stands up:

During barefoot running, the ball of the foot strikes the ground first and immediately starts sending signals to the spinal cord and brain about the magnitude of impact and shear, getting most of its clues about this from the skin contact with the surface irregularities of the ground. Take away this contact by adding a cushioned substance and you immediately fool the system into underestimating the impact. Add a raised heel and the shod runner is forced to land on it. Strap the cushioning on tightly with the aid of a sophisticated lacing system and you block out shear as well, throwing the shock-absorption system even further into the dark…. The cushioned midsole of the modern running shoe robs the system of important sensory information necessary for ankle, knee and hip response to impact. The arch support (or orthotic) in modern running shoes not only prevents the arch suspension system from absorbing energy by preventing flattening but eventually leads to intrinsic muscle atrophy and complete loss of active muscular control of the arch leaving only the inelastic plantar fascia as a checkrein to flattening. The barefoot runner’s ‘foot position awareness sense’ which relies heavily on sensory input from the sole of the foot minimizes his risk of sustaining an ankle sprain on uneven ground. The shod runner is at marked increased risk of ankle sprains because his ‘foot position awareness sense’ is handicapped by the paucity of sensations coming from his soles.

Froncioni highlights here three distinctive problems with shoes in the dynamics of running: the first, a decrease in sensory information available through the foot; second, a shift in the position of the foot from a changed motion including an earlier heal strike and longer stride; and, third, an erosion of the impact-absorbing dynamics of the lower body, especially of the arch of the foot arising from both mechanical properties of the shoe and the previous two problems. Some of these detrimental effects are immediate, but others are gradual and cumulative, conditioning the body in patterns of behaviour and reaction that amount to a kind of adverse training that can result in chronic injury.

After a lengthy discussion in the comments on the Science of Sports blog posting on barefoot and shod running, Ross Tucker concludes that, in his opinion, the primary reason shoes cause injury is not the placement of the foot when it strikes the ground but the fact that heavily padded, stiff-soled shoes diminish sensation in the feet from the ground (similar to what Robbins and Gouw 1991 conclude, though they do so on the basis of less data). Without sufficient sensation, the foot and leg do not compensate as well for the mechanics of running; the feedback cycle is stifled and the dynamic suffers.

Research on foot impact by Robbins and Waked (1997) suggests that balance and impact are closely related, that a person coming down on a soft surface (like a gymnast landing on a thick pad or runner on a spongy shoe) intentionally, though non-consciously, comes down harder in order to find a stable surface. The spongier the landing material, theoretically, the harder the impact because the body seeks to compress the material to find some sort of stable footing.

According to Froncioni, shoes don’t simply disrupt the sensory feedback-control cycle through proprioception or the sense of impact through the legs, but also because wearing shoes changes the way that runners actively pursue sensory information through vision and use their bodies. That is, when we run in heavily cushioned shoes, we look differently and hurl our body against unknown surfaces.

The barefoot runner is constantly alert scanning the ground before him for irregularities and dangers that might cause him injury. The barefoot runner is a cautious runner and actively changes his landing strategy to prevent injury. He treads lightly. The shod runner is bombarded by convincing advertising stating or implying that the shoe he is wearing will protect him well over any terrain and he becomes a careless runner. He is heavy footed.

The loss of sensation in the feet is analogous to the effects of a degenerative disease, ironically enough. That is, by mimicking the long-term effects of neuro-degenerative conditions, shoes may bring on other forms of degeneration in the lower limbs. As Froncioni writes:

Finally, certain diseases in humans can cause a gradual destruction of the sensory nerve endings in the foot (and elsewhere) resulting in a significant increase in lower extremity injuries. Diabetes and tertiary syphilis are two. Extremities so affected are termed ‘neuropathic’. The shod runner, because of his sensory deprivation and high risk of injury may be termed as having ‘pseudo-neuropathic’ feet, a term coined by Robbins.

This and previous two drop quotes from Athletic Footwear and Running Injuries by Joseph Froncioni.

Conditions such as diabetes can throw off the fine orchestration of muscles in the feet that absorb and transfer force, as decreased sensitivity and response cause delays of dynamic reactions in the foot muscles (see Abbound 2002: 171, and for a review). As we’ve already discussed here on Neuroanthropology.net, some researchers who study loss of stability in older people point to diminished sensitivity in the feet as a potential contributing cause of falling. Not surprisingly, one of the prescriptions for people with this condition is to wear thin-soled shoes or, if the condition is worse, ‘high-tops’ so that sensation on the ankles can substitute for sensation on the soles of the feet.

Shoes as developmental niche for feet

People who habitually wear shoes wind up shaping their feet developmentally in distinctive ways. From the point of view of our feet – if I can be so anthropomorphizing – the shoe becomes the ‘environment’ in which feet are grown. Factors like temperature, abrasion, constriction, and the like become the environment with which the foot must contend adapt to, and rely upon. Shoes are a kind of developmental niche for feet, and like any ecological niche, exert their own influence on the anatomical unfolding of the foot’s anatomy. Of course, other factors in addition to shoes make up the foot’s ‘environment’, such as the very act and amount of walking we do, the surfaces we walk on, the sorts of forces exerted upon the bones in the feet by factors like our body size, built environment, athletic activities… and all of these can be affected by shoes, too.

In other words, from the point of view of the feet, a whole constellation of things make up the developmental environment, some of which are truly ‘outside’ us – like cold or wet or surfaces – but some of which are very much under human control, including activity patterns and habitual footwear. To the foot, the leg is part of the environment, and how the leg is used becomes one of the environmental factors feeding into how the feet develop. If we wear a pair of shoes that changes how our legs work (such as high heels or thickly-soled running shoes), these shoes affect the feet directly, but they also impact the feet indirectly through what they do to the leg and the dynamics of our gait and our patterns of activity.

In the simplest sense, shoes are designed to address what the shoe designers perceive as inadequacies in the human foot, whether these inadequacies are mechanical or aesthetic. Adam Sternbergh (2008) explained:

For decades, the guiding principle of shoe design has been to compensate for the perceived deficiencies of the human foot. Since it hurts to strike your heel on the ground, nearly all shoes provide a structure to lift the heel. And because walking on hard surfaces can be painful, we wrap our feet in padding. Many people suffer from flat feet or fallen arches, so we wear shoes with built-in arch supports, to help hold our arches up.

Of course, other design elements enter the mix along the way: the desire to be colour coordinated, the elongation of the leg provided by high heels, the undeniable cool of the tassel, the practicality of Velcro quick-release closures on kids shoes. But the basic ‘functional’ design elements of shoes are relatively consistent since the advent of modern, protective footwear (that is, providing more than simply insulation against cold by wrapping fabric or skin around the foot).

The basic effect of shoes on feet is relatively consistent as well. First, the sole of the shod foot does not develop the hardness that the unshod develop. Anyone who has ever lived in a variable climate (like I did growing up in St. Louis) probably has the experience of their feet fluctuating seasonally in toughness, going from soft and tender when constantly protected during the winter, swaddled in thick socks and insulating shoes, to toughened when barefoot or wearing sandals in the summer. When I worked as a lifeguard, by mid-July I could walk across the sun-heated asphalt parking lot at midday without my shoes. At the start of the summer, pampered winter feet were sensitive to every pebble or crack in the pavement.

In a study of shoe-wearing and habitually barefoot Chinese populations, Sim-Fook and Hodgson (1958: 1059) found:

The feet of the non-shoe-wearing populations showed thick soles with prominent skin creases apart from many minor lacerations due to traumata. The pachydermatous [!!] skin on the sole of the foot had an extraordinarily thick keratinized layer about 0.5 to one centimeter thick which permitted the individual to walk about without any discomfort. Although thick and tough, the skin was pliable and was marked by deep transverse folds which were similar to the lines of joint flexion found on the palm of the hand…

(Before I go any further, ‘pachydermatous’ is the coolest word EVER…)

Even though the groups studied spent quite a bit of time standing in water and unshod, Sim-Fook and Hodgson did not find many complaints about foot health, in part because their soles were so resilient and pliable, but also because the unshod did not have the constant low level friction on their feet provided by shoes. Ironically, this constant, low pressure against the foot can produce more severe chronic injury and malformation than the once-in-a-while and completely varied traumas of walking around with naked feet. Since the bones and tissue are, in a sense, being grown inside the shoes, they struggle to conform to some of the spaces and mechanical environments that we give them.

The second effect of shoes on foot development is that they influence the performance and architecture of the arch of the foot. As Dudley Morton (1964: 145) argued decades ago:

The natural foot is the naked, unclothed foot; and its arched conformation is not an element of weakness in design calling for artificial help, but of structural strength acquired through countless generations of unaided weightbearing. Occasionally we hear shoes referred to as a “natural support for the arch.” The suggestion should move our hearts in pity toward all primitive peoples were it not for the fact that they have no foot troubles, as well as no shoes. The phrase is one of many in which glibness overshadows accuracy, and unfortunately tends to promote erroneous ideas about the foot and its welfare.

The arch of the foot absorbs force when the feet impact the ground, stretching tendons in multiple directions, flattening and deflecting momentum. ‘Supporting’ the arch of the foot by placing it on a convex orthotic would make it virtually impossible for it to function as a shock absorber.

The arch support, which is present in all running footwear, would interfere with the downward deflection of the medial arch on loading. Furthermore, the use of orthodics, or other structures that are fitted to the mold of the soft tissues of the foot, could cause similar difficulty. Such designs occur when an engineer looks at the foot as an inflexible lever which is delicate and thus requires packaging. Various myths persist about foot behavior due to poor understanding of its biology. (Robbins and Hanna 1987)

Shoes also bind together the toes, making it very difficult for them to move, let alone engage in the grasping motions that habitually unshod people make when they walk (see Robbins and Gouw 1990; more on this below). To return to Morton (1964: 218), the bare toes move relative to each other to bear the weight of the body, and shoes affect their angle of spread: ‘The toes of non-shoe-wearing natives are separated when weight is borne on the feet; but any light, closely fitted foot covering will prevent their separation, owing to the lateral mobility of the toes and the small size of the muscles that abduct them.’ Sim-Fook and Hodgson (1958: 1060) also found ‘a tendency to spread’ in the forefoot, especially between the first and second toes (see also Funakoshi 2005).

Normally, the big toe (or hallux) diverges from the second toe at an angle of 5 to 10 degrees. But, in a condition referred to as hallux valgus, the big toe angles toward the small toes. When the condition is also accompanied by hypermobility, it is often congenital and referred to as ‘atavistic’ (although I suspect that this designation is not evolutionarily accurate). But the condition is often caused by wearing ill-fitting shoes, and it occurs 10 times more often in women as in men according to Richardson, Hansen, and Kilcoyne (2000; see also this source for astonishing X-rays of the effects of shoes on bone configuration… I was gobsmacked by a couple of the images). Morton believes that shoes have no noticeable effect on the functioning of toes, but we do know that habitually binding together the toes does affect the skeletal structure of the feet, and the evidence of pathology from shoes seems to me to be pretty compelling.

Patterns of bone growth and remodeling due to use (commonly referred to loosely as ‘Wolff’s law,’ see Ruff et al. 2006) suggest that a shift in toe use and the increased support for the bones of the feet provided by habitually worn shoes, will lead to differences in bone structure between habitually shod and unshod populations (see, for example, Sim-Fook and Hodgson 1958). Bound together laterally and ‘supported’ by an arched shoes, the foot cannot act as efficiently as a shock absorber; at the same time, less dynamic loading on the bones means that the bones will be less robust. Shoes, then, have a range of developmental effects, from low-level, constant pressure and abrasion to a form of protection which leads to greater fragility.

As a result, Zipfel and Berger (2007) recorded substantially higher rates of bone pathology in the feet of shod populations that they studied (European, Sotho and Zulu) than in pre-pastoralist South African populations who likely were habitually barefoot foragers. Although Erik Trinkaus’ work (see below) suggests that pathologies caused by shoes might be uneven distributed among the bones of the feet, Zipfel and Berger (ibid.: 209) found ‘the foot on the pre-pastoralist group is uniformly “healthier” than the modern groups.’

Ironically, even though Zipfel and Berger acknowledge that pre-pastoralist people show some signs of ‘wear and tear’ that might arise from much greater amounts of walking, constant travel and nomadic foraging, this heavy use pattern did not correlate with higher rates of a wide range of bone pathologies.

The results presented here suggest that the unshod lifestyle of the pre-pastoral group was associated with a lower frequency of osteological modification. The influence of modern lifestyle including the use of footwear, appears to have some significant negative effect on foot function, potentially resulting in an increase in pathological changes. (ibid.: 212)

I found it especially curious that the relative rates of pathology types and locations tended to be pretty similar across the different groups, but the overall frequency of pathological conditions varied, with shod populations’ rates of most disorders higher. This suggests that the wear pattern on feet is pretty similar, whether a population wears shoes or not; they get the same sorts of disorders, but less frequently without shoes.

The only way I can explain this is to assume that the shoes themselves don’t cause pathologies (otherwise, we’d notice some abnormally frequent disorders), but that shoes uniformly make the foot susceptible to disordered development. In other words, it’s not the shoes doing the damage, it’s that they throw off the foot’s ability to cope with normal movement, making the organ more fragile and susceptible to all pathologies (but note that this was only a study of bones, not soft tissue lesions).

The problem is not simply that we wear shoes, but that we often don’t wear the right shoes. Abboud (2002:176) reports that,

Since its inception in 1993, most patients seen at the Foot Pressure Analysis Clinic (FPAC) in Dundee, regardless of how minor or complex their problem was, were using ill-fitting footwear with discrepancies in shoe width and size when compared to their feet. In some cases, there was a difference of up to 3 UK sizes and 4 cm in width across the metatarsal head area, needless to say causing abnormal biomechanical force through the foot joints. The cumulative damage caused by footwear over the years goes inmost cases unnoticed and gets ignored despite clear signs of pain and dorsal callus formation, the latter can only develop as a result of friction with the inner shoe.

I probably don’t need to remind you that, as an anthropologist, I make little distinction between what people ‘should’ be wearing and what they actually are wearing. From the point of view of the feet, ill-fitting shoes are just as much a part of the developmental niche as perfectly chosen footwear.

Sternbergh explains the developmental influence of shoes simply: ‘This is the shoe paradox: We’ve come to believe that shoes, not bare feet, are natural and comfortable, when in fact wearing shoes simply creates the need for wearing shoes.’ Shoe designers are convinced that feet need to be protected against the ground, and the result is that our feet are so sheltered that they do become fragile.

The earliest shoes

Otzi's shoe

Archaeologist Erik Trinkaus has written a number of articles on the evidence for footwear in prehistoric populations, arguing that, in order to survive the cold of glacial periods, hominins would have necessarily figured out how to create insulating protection of some sort: a kind of prehistoric Ugg boot. But more modern-style, mechanically supportive shoes would have been a later development, evident in the bones of the feet because a semi-rigid sole will alter the distribution of force on the foot (see Trinkaus 2005: 1516). When walking barefoot, the toes flex, making the bones on the outside of the foot stronger through remodelling (as mentioned in the previous section); Trinkaus hypothesized that a shift in the robusticity of bones in the hallux (big toe) relative to the smaller toes (or the outside of the foot) would be a possible sign of habitual hard-soled shoe wearing.

Trinkaus compared bones from three different recent North American populations to test the hypothesis that shoes caused shifts in the relative strength of the toe bones (Pecos Pueblo Native American, Inuit, and Euro-Americans). Within these samples, predictions about the robustness of the phalanges in the feet based upon their shoe-wearing patterns turned out to be accurate; Pecos Pueblo Native Americans wearing soft-soled moccasins had the most robust lateral toes, Inuit in harder soled boots had more gracile bones, and Euro-Americans in hard-soled shoes had the most marked disparity. The more support offered by the footwear, the less robust the bones of the feet associated with the smaller toes (especially the pedal proximal phalanges in the middle of the foot).

Trinkaus has used beam model analysis, a technique that scans cross sections of bones across their axis to get some idea of their density and configuration. These donut-like images gives some sense of the stresses placed upon the bones because they remodel to compensate for these stresses, get stronger, in general, to withstand habitual strains.

A similar comparison might provide insight into the earliest rigid footwear because, as Trinkaus puts it, ‘relative robusticity of human lateral toes might provide insight into the frequency of use of footwear’ (2005: 1515). Because the organic materials likely used to make the first shoes would not endure in the archaeological record, Trinkaus’ method is as intriguing as it is ingenuous. In the archaeological remains Trinkaus examined, the evidence from the feet suggest that shoes became more and more prevalent from the Middle Paleolithic to the middle Upper Paleolithic; he suggests supportive footwear is likely around 30,000 years old in his earlier work (2005), but some of his later work with Shang (2008) may push that date back closer to 40,000 years.

I’m not going to go into all of Trinkaus’ analysis here. Blogger Afarensis has a number of posts on the issue of prehistoric footwear including here, here and here. Please read Afarensis, especially What You Can Learn From Bones: When Did We Start Wearing Shoes? for a more complete discussion of Trinkaus’ work.

By comparing the shoes to an ‘environment,’ I don’t mean to suggest that 40,000 years of being shod is a form of ‘unnatural selection’ that has shifted the genetic contributors to the anatomy of our feet. Rather, I just mean to suggest that, if shoes are affecting the anatomy of our feet, we have been transmitting certain kinds of crucial traits through the artificial environment that we’ve created. We place our children in little training shoes so that their feet are sculpted into a configuration that fits within, and virtually demands the support of shoes. So should we lose our shoes and go back to ‘natural’ feet, unwinding perhaps 40,000 years of non-genetic biophysical heredity?

Paleo-nostalgia and lifestyle advice

from barefooted.com

I suspect that I usually disappoint my students, who can be pretty fervent about these ideas. Most paleo-nostalgia movements seem to me to be very selective – for example, the whole Paleolithic Diet movement seems to overlook a host of problems, such as changes in activity patterns, the difference between wild and domesticated meat animals, the high incidence of parasites and low life expectancy in prehistoric periods, and the likelihood that much of human protein was not coming from delicious medium-rare steak or grilled chicken breasts but rather invertebrates, shell fish, small vertebrates, offal and carrion (that’s right, maybe it should be the ‘Bugs, Clams, Lizards and Roadkill Diet’ – not quite the same marketing potential as ‘Eat All the Steak and Chicken You Can!’). I’ve discussed this in Paleofantasies of the perfect diet – Marlene Zuk in NYTimes.

So what about shoes and foot health? Is there anyone out there preaching the Paleolithic Podiatry program? Zinjanthropus shares my scepticism of podiatric paleo-nostalgia, asking why one period of our evolutionary history is privileged over others. Zinjanthropus writes:

Either way, I’m usually very cautious about shaping my lifestyle to fit the needs of a paleolithic savannah-scape. We’ve done a lot of evolving since then, after all! If I push my lifestyle back to the Paleolithic, then who’s to say that I’m not even BETTER evolved for the Pliocene?

If a hunter and gatherer diet, for example, is allegedly ‘healthier,’ why not push back to a diet of astringent fruit like our arboreal ancestors (as Richard Wranger points out, you’d be able to look forward to hours every day of chewing to get enough calories, for example).

Paleonostalgia suffers from a number of deep problems. As Zinjanthropus suggests, how to choose which period in time to use as a model. Hominins have evolved over millions of years through a whole range of environments; paleonostalgia tends to arbitrarily pick a point of time in the past, which is not necessarily more valid as a lifestyle model than any other. In addition, paleonostalgists tend to ignore the likelihood that human niches were varied – not as varied as later humans – but the ability to occupy diverse environmental niches has been a hallmark of our ancestors. Too much dietary and environmental specialization hasn’t really been a hallmark of our genus; arguably, the members of our genus and closely allied ones who have become too specialized and inflexible, have all gone extinct (I don’t want to argue this too strenuously, as many of the ones we tend to consider highly specialized a) lasted a hell of a long time, longer than Homo sapiens in some cases, and b) we’re increasingly uncertain that we can know for certain adaptive behaviours from anatomy, as the case of Paranthropus teeth suggests.).

Similarly, discussions of evidence from foraging peoples is often just as selective and slanted. Although we hear about the running capabilities of foraging people (and I, too, firmly believe that they were much more active than technologically-dependent sedentary people), we don’t hear about their injuries, including disabling ones, or their chronic health problems, including things like parasites that enter the body through the feet.

Alfred Gell, for example (I’m pretty sure, but I can’t remember in which text), wrote about travelling quickly through the rainforest with barefoot colleagues; although they were swift and sure-footed, they also had to stop every once in a while when one of them had to dig a thorn out of his or her foot.

One problem with paleonostalgia for barefoot running is the fact that we do not run in a paleolithic environment. As Trimble writes in Popular Mechanics:

The problem modern-day runners face, according to Hugh Herr, Popular Mechanics 2005 Breakthrough Award winner and head of the biomechatronic group at MIT, isn’t presented by our bodies but by the evolution of running surfaces. Humans that ran to scavenge or hunt for their food weren’t pounding concrete.

Running shoes offer a trade-off:

In his research, Herr focused on two problems with both shod and barefoot running-pronation angle and impact force. While barefoot running is best for a natural, stress-free pronation angle, Herr says, it is not ideal for coping with roads and sidewalks that can lead to stress-impact injuries. Shoes, on the other hand, excel at diminishing the force of impact on hard ground. But they do so at the cost of the natural stride-all the padding added to the shoe exaggerates the foot’s rotation.

So just throw away your shoes, right, and let your feet be free? Well, even the proponents of barefoot running caution that the transition from being habitually shod to running around au naturale can take some time because ‘the change in biomechanics and loading of joints, muscles and tendons threatens injury if you’re not careful’ (Tucker and Dugas, Running Shoes).

If running barefoot is so ‘natural’ to humans, why do we have to take it slowly? Because our feet become well adapted, as best they can, to wearing shoes. For all of the discussion of evolution having shaped human bodies and our feet for running, the body that habitually walks and runs in shoes has very much adapted to that niche. (See, for example, Tucker on attempts to change running techniques.)

But an interesting example of just how adaptable the feet can be comes from Shulman’s (1949) study of Chinese and Indian populations, in particular some individuals who might be expected to have the most damaged feet (if shoes were necessary to save our feet):

One hundred and eighteen of those interviewed were rickshaw coolies. Because these men spend very long hours each day on cobblestone or other hard roads pulling their passengers at a run it was of particular interest to survey them. If anything, their feet were more perfect than the others. All of them, however, gave a history of much pain and swelling of the foot and ankle during the first few days of work as a rickshaw puller. But after either a rest of two days or a week’s more work on their feet, the pain and swelling passed away and never returned again. There is no occupation more strenuous for the feet than trotting a rickshaw on hard pavement for many hours each day yet these men do it without pain or pathology.

Weren’t our feet designed for running barefoot?

In fact, a number of recent articles suggest that some of the traits of the foot (and other parts of the body) indicate that an ability to run barefoot might have offered a selective advantage during human evolution (e.g., Bramble & Lieberman 2004; see also Wired Science, These toes were made for running). But I don’t think that the issue is simply a debate between the running shoe industry and the growing ‘natural’ barefoot running movement. Instead, the anatomy of the foot, its sensitivity in development to the presence of shoes, and the evolutionary development of shoes and bipedalism, all illustrate how hard it is to talk about the natural human body at all or what the human body is ‘designed’ to do.

Patterns of activity, the most minimal technology, and the way we restructure our living environments all shape our physiological development. In fact, the role of activity, motor experience, and sense perception is so crucial in the development of so much of the human body and nervous system that I suspect we cannot even imagine how a person ‘without’ these sorts of influences might develop. Because humans are inherently adaptable — through culture, learning, technology, and even physiological change – it makes sense that plasticity itself would be a trait likely selected for in humans (an idea I take from Mary Jane West-Eberhard [e.g., 2005]).

Faced with the evidence that something as simple as wearing shoes can affect our soft tissue physiology, skeletal structure, gait kinetics, and the like, we can ask whether being shod or unshod is our ‘natural’ state. In a number of the internet postings about barefoot running, I find assertions about what sorts of surfaces or types of locomotion the human foot was ‘designed’ to accomplish. I think it’s too easy to just say, ‘barefoot is natural; shoes are artificial; feet were designed to run.’

In fact, the human foot and lege were not ‘designed’ for running or walking, barefoot or otherwise. They were not ‘designed’ at all. Evolution doesn’t design anything. Legs and feet are built by natural selection out of an appendage that, a very very long time ago, was a fin. If you were going to ‘design’ a limb and foot for running, you could do a lot better than the human architecture. Our knees, for example, are really lousy; they’re basically a rejiggered hinge joint and could certainly have been engineered better by a benevolent Creator. And She could have given us a more elastic set-up of tendons, too, something like kangaroos have. Oh, man, if some genetic engineer could just work on that kanga-human hybrid (a ‘kanga-hu’?), Olympic steeplechase would be so cool; no more of that stepping on top of the jump and landing in the water – but I digress.

Most of our readers will, of course, be completely familiar with the problems of the ‘Natural Selection as Designer’ metaphor, but it’s one that still crops up again and again in discussions of the evolution of traits. Normally, we can get by with the ‘design’ metaphor without too much trouble, but in the case of something like the role of activity in shaping the emergence of a physiological trait.

You see, human feet aren’t just good for running. They’re good for walking, standing, swimming, lifting, kicking, and a host of other functions. Like most primates, our limb use is actually pretty versatile; the arboreal niche of our ancestor presented a wide variety of challenges – hanging, swinging, walking on top of branches, standing bipedally, standing on all four. In addition, our primate ancestors, like us, don’t just use their limbs for locomotion; they use their limbs to manipulate objects, process food, hold offspring, interact socially, protect themselves, and a host of other activities.

Wait, you say, but we don’t use our feet this way. We’re humans. Feet are for walking and running…

Well, here’s the thing. Feet aren’t just ‘designed for’ walking or running; they turn out to be useful for all sorts of things. In the Chinese populations that Sim-Fook and Hodgson (1958: 1061) studied, habitually unshod people used their big toes often ‘to hold fishing nets and fishing lines taut so that the hands were free.’ The result was that these individuals developed ‘a remarkable degree of prehensile strength’ in the big toe (ibid.: 1060-1061). They conclude their discussion of the ‘unshod foot’ with the summary: ‘The unshod foot had laxity of the joints and tissues producing, in its natural form, a flexible foot with a degree of metatarsus latus, metatarsus primus varus, and hypermobility.’

You or I or the next guy may not be using our feet for things like peeling fruit or dialing the phone, but that doesn’t mean it can’t be done. In fact, many individuals congenitally born without arms or unable to control their arms due to a condition like cerebral palsy develop extraordinary dexterity with their feet, not only using them to do everyday tasks, but even activities like painting or playing an instrument. Painter Chan Tung-mui, for example, paints watercolours with her feet because she cannot control her hands due to cerebral palsy.

Simona Atzori

In most humans, especially shoe-wearing humans, the hallux is adducted, that is, in line with the other toes; but some degree of abduction is present in many of us, especially if habitually unshod, and may even develop to a slightly greater degree with use. Of course, no one approaches the abduction angles of our primate cousins who dwell in trees and have fully-functioning prehensile feet, but this crucial detail of human anatomy, one that distinguishes us from others, may be more variable than we think.

Shulman (1949) makes an off-handed remark about this that I found incredibly interesting: ‘Almost everyone surveyed showed a marked spacing between the first and second toes such as that found on young babies.’ I don’t know about the developmental dynamics, but it wouldn’t surprise me too much if, absent the adducting influence of shoes for more than half of our lives, and an even greater proportion of the time in which our feet were weight bearing, the angle of the toes found in infants was closer to the habitually unshod.

Although we may think that the Chinese practice of foot-binding is a kind of aberration, Zipfel and Berger (2007: 205-206) suggest on the basis of previous research that many Asian populations reveal the degree to which conventional shoes bind feet: ‘Studies of Asian populations whose feet were habitually either unshod, in thong-type sandals or encased in non-constrictive coverings have shown increased forefoot widths when compared to those of shod populations.’

As I wrote in the paper I presented at Univesité Montpellier (Downey 2009), just as Clifford Geertz (1973:67-68) argued that an uncultured human being would be a ‘mindless and consequently unworkable monstrosity,’ a skill-less human would not be capable of the most basic, defining ‘human’ physical acts. The fact that skills like foot painting or feeding oneself with one’s feet are rare does not mean that our feet were not ‘designed’ to do them.

If we were looking for a ‘natural’ foot, one without any influence of activity, we should probably focus on infants or on those who are disabled. We should realize that our feet were not ‘designed’ to do one thing or another; caring for them, and shaping them in ways that we desire, requires more than just figuring out what our ‘nature’ might be.

UPDATE: In January 2010, this issue was in the news due to the release of a new study suggesting that knee, ankle and hip damage might be greater for shod than unshod runners. Some sources have made the leap to the likelihood of osteo-arthritis, although the original study was biomechanical in nature. For a popular version:
Running Shoes May Cause Damage to Knees, Hips and Ankles, New Study Suggests
The original article (and abstract) is available here for download as a PDF:
Kerrigan, D. Casey, MD, Jason R. Franz, MS, Geoffrey S. Keenan, MD, Jay Dicharry, MPT, Ugo Della Croce, PhD, Robert P. Wilder, MD. 2010. The Effect of Running Shoes on Lower Extremity Joint Torques. PM&R 1 (12): 1058-1063. DOI: 10.1016/j.pmrj.2009.09.011

Stumble It!

More reading
Bare Feet by Zinjanthropus at A Primate of a Modern Aspect

Ross Tucker and Jonathan Dugas at The Science of Sport published a whole series on running shoes and running dynamics in 2008:
Part 1: Do shoes cause injury?
Part 2: Shoes, injuries and training
Part 3: Running barefoot – the intelligent biomachine
Part 4: The footstrike – how should your foot land?
Part 5: The market and evolution of the shoe industry

Dylan Tweeny. 2008. Your Shoes Are Killing Your Feet. Wired Science (23 April). http://www.wired.com/wiredscience/2008/04/your-shoes-are/

Amby Burfoot. 2004. Should You Be Running Barefoot? Runner’s World. Available at: http://www.runnersworld.com/article/0,7120,s6-240-319–6728-0,00.html

Adam Sternberg. 2008. You Walk Wrong. New York Magazine (28 April). Available at: http://nymag.com/health/features/46213/

Tyghe Trimble. 2009. The Running Shoe Debate: How Barefoot Runners are Shaping the Shoe Industry. Popular Mechanics (22 April). Available at: http://www.popularmechanics.com/outdoors/sports/4314401.html

Joseph Froncioni. 2006. Athletic footwear and running injuries. Quickswood weblog (22 August 2006, but Froncioni admits to writing it much earlier).

Runner’s World’s ‘barefoot running’ forum.

Barefoot Ken Bob’s website http://runningbarefoot.org/
Barefoot Ted’s website http://barefootted.com/
Barefoot Rick Roeber’s website http://barefootrunner.org/ (Is it just me, or is there a pattern here?)
…El gringo sin los zapatos … Barefoot running blog
Barefoot vs. the Shoe blog, which hasn’t been updated in a while, but the truly obsessive might find interesting
And if anyone else wants to read it in Portuguese, there’s Correndo Descalço.

Credits
Photo of runners in the 1984 Olympics from the site, Barefoot Concepts.

Painted foot. Photo by Tom Schierlitz; makeup by John Maurad and Jenai Chin.
From You Walk Wrong, by Adam Sternbergh, the New York Magazine.

References

Abboud, R. J. 2002. Mini-Symposium: The Elective Foot: (i) Relevant foot biomechanics. Current Orthopaedics 16(3): 165-179. doi:10.1006/cuor.2002.0268 (abstract)

Bramble, Dennis M., and Daniel E. Lieberman. 2004. Endurance running and the evolution of Homo. Nature 432 (18): 345-352.

Burge, Caroline. 2001. Comment on Barefoot Running. Sportscience 5(3), sportsci.org/jour/0103/cb.htm

Clinghan, R., G. P. Arnold, T. S. Drew, and L. A. Cochrane. 2008. Do you get value for money when you buy an expensive pair of running shoes? British Journal of Sports Medicine 42(3): 189-193. doi: 10.1136/bjsm.2007.038844

De Wit, Brigit, Dirk De Clercq, Peter Aerts. 2000. Biomechanical analysis of the stance phase during barefoot and shod running. Journal of Biomechanics 33: 269-278

Divert, C., G. Mornieux, H. Baur, F. Mayer, and A. Belli. 2005. Mechanical Comparison of Barefoot and Shod Running. International Journal of Sports Medicine 26(7): 593-598.

Divert C., G. Mornieux, P. Freychat, L. Baly, F. Mayer, and A. Belli. 2008. Barefoot-shod running differences: shoe or mass effect? International Journal of Sports Medicine 29(6): 512-518.

Downey, Greg. 2007. Producing Pain: Techniques and Technologies in No-Holds-Barred Fighting. Social Studies of Science 37(2):201-226.

_____. 2009. ‘Interculturality, body & movement: On studying someone else’s skill.’ Keynote lecture. Conference: Le Corps em Mouvement 2, Francophone Association for Research on Physical and Sportive Activities, Université Montpellier 2 and Santésih Laboratory (Health, Education and Disability Situations), 4 June.

Driscoll, Dennis G. 2004 (2003). Barefoot Running: A Natural Step for the Endurance Athlete. Track Coach 168: 5373-5377. Available in several forms online, such as in manuscript form here.

Funakoshi, Kimitake. 2005. Secular changes in the angle of divergence of the first two metatarsals in the Japanese. American Journal of Physical Anthropology 75(3): 341-345.

Morton, Dudley J. 1964. The Human Foot: Its Evolution, Physiology, and Functional Disorders. New York and London: Hafner Publishing.

Richards, Craig E., Parker J. Magin, and Robin Callister. 2009. Is your prescription of distance running shoes evidence based? British Journal of Sports Medicine 43(3): 159-162. doi:10.1136/bjsm.2008.046680

Richardson, Michael L., Sigvard T. Hansen, and Ray F. Kilcoyne. 2000. Radiographic Evaluation of Hallux Valgus. From the University of Washington School of Medicine, Department of Radiology website. Accessible at http://www.rad.washington.edu/anatomy/halluxvalgus.html (accessed on: 27 June 2006).

Robbins, Steven E., and Gerard J. Gouw. 1990. Athletic footwear and chronic overloading. Sports Medicine 9(2): 76-85.
_____. 1991. Athletic footwear: unsafe due to perceptual illusions. Medicine and Science in Sports and Exercise 23(2): 217-224

Robbins, Steven E., and Adel M. Hanna. 1987. Running-related injury prevention through barefoot adaptations. Medicine and Science in Sports and Exercise 19(2): 148-156.

Robbins S, and E. Waked. 1997. Hazard of deceptive advertising of athletic footwear. British Journal of Sports Medicine 31: 299-303. doi:10.1136/bjsm.31.4.299. (Abstract and full text.)

Ruff, Christopher, Brigitte Holt, and Erik Trinkaus. 2006. Who’s Afraid of the Big Bad Wolff?: ‘‘Wolff’s Law’’ and Bone Functional Adaptation. American Journal of Physical Anthropology 129: 484-494. doi 10.1002/ajpa.20371

Shulman, Samuel B. 1949. Survey in China and India of Feet That Have Never Worn Shoes. The Journal of the National Association of Chiropodists 49: 26-30.

Sim-Fook, Lam, and A. R. Hodgson. 1958. A Comparison of Foot Forms among the Non-Shoe and Shoe-Wearing Chinese Population. Journal of Bone and Joint Surgery 40: 1058-1062.

Trinkaus, Erik. 2005. Anatomical evidence for the antiquity of human footwear use. Journal of Archaeological Science 32: 1515–1526. doi:10.1016/j.jas.2005.04.006

Trinkaus, Erik, and Hong Shang. 2008. Anatomical evidence for the antiquity of human footwear: Tianyuan and Sunghir. Journal of Archaeological Science 35 (7): 1928-1933. doi:10.1016/j.jas.2007.12.002

West-Eberhard, Mary Jane. 2005. Developmental plasticity and the origin of species differences. Proceedings of the National Academy of Sciences USA 102 (suppl. 1): 6543-6549. www.pnas.org cgi doi 10.1073 pnas.0501844102

Wharburton, Michael. 2001. Barefoot running. Sportscience 5(3). sportsci.org/jour/0103/mw.htm. (pdf available)

Zipfel, B., and L. R. Berger. 2007. Shod versus unshod: The emergence of forefoot pathology in modern humans? The Foot 17: 205–213. doi:10.1016/j.foot.2007.06.002

A young Andre Agassi

Or, confronted by the yawning gap between elite athletes’ performances and the ability of the average person, sceptics still want to focus on the slight differences among elites athletes (for example, Jon Entine’s book Taboo), suggesting that this tiny fraction of difference is the ‘innate’ part, the ‘talent.’ I can describe the years of arduous labour that go into producing elite-level achievement, the countless hours of training and sophisticated coaching, and someone will inevitably say, ‘Okay, but some people are just inherently good at sports, aren’t they?’

But as psychologist K. Anders Ericsson said in an interview in Fast Company (cited here by Dan Peterson), ‘The traditional assumption is that people come into a professional domain, have similar experiences, and the only thing that’s different is their innate abilities. There’s little evidence to support this. With the exception of some sports, no characteristic of the brain or body constrains an individual from reaching an expert level.’

Obviously, certain dimensions of the body can affect one’s ability to participate in a sport like basketball or sumo at an elite level, or a genetic abnormality may create an unusual wrinkle in a metabolic or even a neural process, but research like Ericsson’s suggests that these sorts of traits are likely the exception rather than the rule. That is, even if there is a genetic trait that helps some Kenyan runners to excel, or gives an individual with photographic memory, or helps a free diver to endure oxygen deprivation, these cases do not confirm the folk idea that talent is innate (and thus likely genetic).

In this post, I want consider the difference that makes a difference. That is, how the concept of talent itself actually affects the unfolding and compounding of developmental variation, helping extreme ability to emerge (and de-motivating those who don’t demonstrate early ‘promise’). Whether or not ‘talent’ exists—and I’m profoundly skeptical—believing that it does is a good foundation for exaggerating variation in skilled ability.

What is talent and how to identify it

‘Talent’ or ‘potential’ are ways that some of us think about inequality in ability, or variation in the way that different people seem to benefit from training. ‘Talent’ is alleged a potential trait, a symptom of nascent ability, a foreshadowing of future greatness, or a way of explaining someone’s early achievements or performance advantage. On the other hand—paradoxically—the concept of talent is a way of understanding why some experts are more proficient than others; unlike a concept like jeito, a Brazilian term for something like a ‘knack,’ ‘talent’ is usually quite task specific or specialized, even though a ‘talented’ person is often quite versatile.

‘Talent’ is typically contrasted with ‘hard work’ or ‘determination,’ suggesting skill is some mix of natural ‘talent’ and ‘hard work,’ in various proportions. The cultural concept of ‘talent’ is a bit unstable; no one would expect a talented musician to simply pick up an instrument and play. Rather ‘talent’ is usually an idea that some people learn quicker, more effortlessly, and with greater effect. In some ways, ‘talent’ can be like a multiplier, allowing a person to get more out of formative experiences and instruction.

At times, ‘talented’ seems to mean little different from skilful, but ‘talent’ also has a bit of an edge: it can be an evaluation tinged with disappointment, ‘squandered talent,’ a suggestion that a person has potential which may not have been fully developed because of other failures, like an absence of hard work or discipline.

In sports, there’s sometimes the suggestion that ‘talent’ might have biological or even genetic roots, although there is little evidence (yet?) to support this assumption. We sometimes think of talent as running in families, one way to explain sports dynasties other than role modelling, expert in-house coaching, or increased opportunities from association with a successful predecessor.

Howes et al. (1998:2) offer five properties alleged to be true of ‘talent,’ and compare each with extant research that either demonstrates or undermines these propositions implicit in folk ideas of ‘talent’:

1. It originates in genetically transmitted structures and hence is at least partly innate.
2. Its full effects may not be evident at an early stage, but there will be some advance indications, allowing trained people to identify the presence of talent before exceptional standards of mature performance have been demonstrated.
3. These early indications of talent provide a basis for predicting who is likely to excel.
4. Only a minority are talented; if all children were talented, then there would be no way to predict or explain differential success.
5. Talents are relatively domain-specific. (This summary of Howes et. al. 1998, appears in Helsen et al. 2000: 728).

An entire specialized research literature, much of which is not published but held privately by various sports organizations, is dedicated to ‘talent identification,’ to the incredibly difficult business of figuring out which young athletes will reward serious investment of training resources. Especially as states spend scarce resources trying to achieve high prestige athletic outcomes, most extravagantly focusing on Olympic medals, the energy and research focused on talent identification, already great, is likely to increase. And judging from what I’ve read, this is still likely to be a hit and miss endeavour for reasons that will become clear .

For example, the Australian Sports Commission provides a series of resources intended to help coaches identify promising athletes as young as twelve years of age. Their website has a self-administered eTID, an electronic talent identification test.

eTID is the brainchild of the Australian Sports Commission’s successful National Talent Identification and Development (NTID) program which seeks to identify and develop Australia’s future sporting talent. This interactive website allows users to enter in results for a series of simple ‘home based’ performance tests and measurements which can be used to help identify athletes for selection in NTID development programs….

If your results are identified as above average you will be encouraged you to visit a Talent Assessment Centre (TAC) to have your results verified. After assessment, you may then be able to enter the elite sporting system, where you could be supported with coaching, equipment and travel.

Likewise, in the lead up to the 2012 Olympic Games in London, UK Sport has rolled out an ambitious talent identification program, but these sorts of programs are hardly knew; ‘talent identification’ and state support for athletic training was a battleground for prestige during the Cold War, producing generations of world class athletes, sometimes in conditions that amounted to gilded slavery.

But talent identification is tricky business, and it’s unclear whether tests or screening do anything other than confirm what coaches and spectators already know (‘hey, that kid is fast), or expose physically fit kids to sports that they might otherwise not consider doing. Neither of these two really confirms that ‘talent’ exists; one simply means that people who are good at athletics tend to stay good or get better with support, the other that skilful athletes are sometimes better than other beginners at sports they’ve never tried. As the SPARC-commissioned Talent Identification and Development Taskforce of New Zealand reports:

The Taskforce’s conclusion, consistent with findings by sports science researchers world wide, is that there is no simple way to accurately identify future talent as talent is multi-dimensional. It can emerge at any point during an athlete’s development, and is affected by factors such as genetics, environment, mental, physiology and support. However, it is possible to create an environment that increases the chances of athletes fulfilling their potential.

That is, in other words, we don’t know exactly what it is or how to identify, or even when exactly it would show up, but we know talent exists. So we should give everyone support because eventually, we’ll see who gets good and those are the ones with talent. Fair enough, but hardly proof that ‘talent’ even exists.

Some of the examples of successful ‘talent identification’ in sports are hardly compelling proof that we are close to some consistent diagnostic for talent. Stories about successfully converting sprinters with good upper body strength into pushers for an Olympic bobsled, or of training a champion beach sprinter who must accelerate in slippery sand and dive after a baton into a world-class skeleton rider who must accelerate on slippery snow until diving onto a sled face first, hardly demonstrate a penetrating perception of untapped athletic ability. In fact, it’s more likely a commentary on how core techniques may be closely related in diverse sports.

Studies of expert performance

Although the idea that excellence is innate, at least as some kind of hard-to-define ‘potential,’ dies hard, research by psychologist K. Anders Ericsson strongly suggests that skill emerges out of deliberate practice rather than being born in a person.

Popular lore is full of stories about unknown athletes, writers, and artists who become famous overnight, seemingly because of innate talent—they’re ‘naturals,’ people say. However, when examining the developmental histories of experts, we unfailingly discover that they spent a lot of time in training and preparation. Sam Snead, who’d been called ‘the best natural player ever,’ told Golf Digest, ‘People always said I had a natural swing. They thought I wasn’t a hard worker. But when I was young, I’d play and practice all day, then practice more at night by my car’s headlights. My hands bled. Nobody worked harder at golf than I did.’ (Ericsson, Prietula and Cokely 2007)

K. Anders Ericsson, FSU

When most people practice, they focus on the things they already know how to do. Deliberate practice is different. It entails considerable, specific, and sustained efforts to do something you can’t do well—or even at all. Research across domains shows that it is only by working at what you can’t do that you turn into the expert you want to become.

The problem for many people is that they’re not practicing deliberately; if they did, they would see a bigger improvement in their performance.

Ericsson and Lehmann (1996), for example, discuss a host of studies that converge on the realization that ‘talented’ individuals take virtually the same amount of time to achieve expert performance as their less gifted colleagues, we just don’t tend to notice it. The physical and neurological traits necessary for expert performance tend to be the result of, not the precondition of, increasingly skilful performance and this extended apprenticeship in physical techniques (Ericsson and Lehmann review a host of examples, such as ‘perfect pitch’ in music, chess ‘prodigies,’ ballet ‘turn-out,’ and ratios of fast twitch to slow twitch muscles, all of which appear malleable given the right timing and conditions).

An article in The Australian describes how Ericsson’s research undermines the idea that ‘talent’ exists at all:

Ericsson’s theories confound the beliefs of thousands of years. Now as Conradi eminent scholar at Florida State University in Tallahassee, where he has been based since 1992, his basic argument is that there’s probably no such thing as innate talent or, if there is, it’s overrated. The only thing he will allow is that very occasionally certain physical gifts, such as height in a basketballer, will help. But in every other case, what’s at work in such massive successes as golfer Woods is a complex cognitive process that pushes the body and mind to extraordinary heights. (From ‘Success is all in the mind,’ by Shelley Gare)

In fact, Ericsson and Lehman suggest that the kinds of basic testing involved in much ‘talent identification’ may not be an indicator of success at specialized, skill-demanding activities:

Reviews of adult expert performance show that individual differences in basic capacities and abilities are surprisingly poor predictors of performance (Ericsson et al. 1993, Regnier et al. 1994). These negative findings, together with the strong evidence for adaptive changes through extended practice, suggest that the influence of innate, domain-specific basic capacities (talent) on expert performance is small, possibly even negligible. We believe that the motivational factors that predispose children and adults to engage in deliberate practice are more likely to predict individual differences in levels of attained expert performance. (Ericsson and Lehmann 1996: 281)

Even in seemingly simple tasks that would require basic differences in neurophysiology, ‘talented’ individual don’t tend to measure that differently from normal people on general measures. For example, ‘Numerous studies of basic perceptual abilities and reaction time have not found any systematic superiority of elite athletes over control subjects,’ even in athletes doing high speed interception tasks, an area where we might expect to find these differences (Ericsson and Lehmann 1996: 280; see also Abernethy 1987; and Starkes and Deakin 1984 for reviews). Legendarily, for example, Sir Donald Bradman, possibly the greatest cricket batsman ever to play the game, had reaction times on normal tests that were similar to a researcher’s control subjects who were college students.

For many readers, Ericsson’s work is a revelation, a way to—as Ericsson, Prietula and Cokely (2007) put it—‘demythologize’ the legend of the ‘natural’ expert or the gifted ‘prodigy.’ They point out that even Wolfgang Amadeus Mozart actually trained vigorously from the age of four, and benefited from having a father who was not only himself an accomplished composer and famous music teacher, but also author of one of the first books on violin instruction. A number of recent books, including Geoff Colvin’s (2008) Talent Is Overrated, and Daniel Coyle’s (2009) The Talent Code: Greatness Isn’t Born. It’s Grown. Here’s How, provide popular versions of Ericsson’s research, which has appeared in a number of forums. I’ve sampled some Coyle’s, and he highlights the environments that produce extraordinary hotbeds of ‘natural’ talent, such as the high intensity ‘salon soccer’ in Brazil that shapes players legendary ball handling skills.

Talent: A difference that makes a difference

Some frequent readers may think that, since I seem to often argue for the influence of ‘nurture’ or environmental effects on emerging traits, I would fall into line with Ericsson’s work, so powerful a case does he make for the production of expertise by systematic practice. What I will suggest instead is that, in a neuroanthropological model of talent, we must take account of how very early differences in ability or behaviour intersect with cultural conceptions of ‘talent’ to feed the dynamics that Ericsson describes. That is, as Ericsson is so clear, access to coaching and motivation are crucial to the emergence of expertise, and both of these resources are culturally shaped to intersect with early physiological and neural traits.

Cultural notions of ‘talent’ and very early differences in children both play a crucial part in the practical processes that produce expertise, even if only as a gateway variable preventing many from ever getting the resources necessary for deliberate practice.

In what is perhaps an overly glib description, I would say that from a neuroanthropological perspective, ‘talent’ is a difference that makes a difference. That is, my research on ‘talent’ across cultures—admittedly still very much in the developmental stage—suggests that different societies, diverse approaches to coaching or athletic environments, and various sporting regimes label different traits ‘talent’ or cause an athlete to stand out. That is, what one coach might call ‘talent’ another might not consider the clinching detail; a trait that might make an athlete stand out in one style of competition might not be salient in another.

For example, I remember very clearly being in grade school and playing a lot of soccer; at one point, ‘juggling’ a soccer ball became a measure of aptitude for playing in elite teams. That is, being able to stand in one place and keep the ball in the air by playing it off the feet, knees, chest, head and shoulder, emerged as the gold standard of ‘talent’ or excellence. Those soccer players who did not juggle as well as their peers were ‘less talented,’ even though they might be extraordinarily fleet of foot, have great endurance, have a vicious shot, or have excellent anticipatory ability for playing defence. Juggling was actually a separate skill, learned outside of playing, but it was taken as an index of ‘potential.’

This particular difference trumped other types of difference that might be seen as indicating future promise. In fact, the trait highlighted as a marker of ‘talent’ might be linked to future expert performance or skill, but not necessarily in a direct way. That is, unlike Ericsson’s model, I’m agnostic about ‘talent’ because I believe it is possible—possible—that very early differences in ability might be linked to later differences in experts’ abilities, but my observations lead me to be deeply dubious.

So how do we understand the links between early and later differences in abilities? Bear with me while I provide a diagram.

‘Talent’ as a cultural model

(c) 2009 Greg Downey

The three arrows across the whole diagram are intended to indicate a difference of scale; factors at the top are socio-cultural in scale, in the middle are psychological or individual, and at the bottom are neurological or physiological. Developmental time is meant to stretch from left to right so that the middle arrow is a kind of biographical trace.

The diagram is intended to suggest how cultural notions of talent, coupled with physiological, neurological and behavioural difference, lead some individuals to be labelled ‘talented.’ On the cultural side, there’s a complication which arises with specialized coaches or ‘talent scouts,’ who often possessing specialized knowledge or techniques, but are also influenced by predominant ideas of talent, just as they impose their own on young athletes.

One area I’m trying to study is how the front-line of contact with coaches, the individuals working with junior athletes, do or do not incorporate new research and ideas disseminated by sports governing bodies, researchers, professional coaches and the like. I suspect that there may be enormous inertia against, or even outright defiance of, sophisticated models of how expertise emerges coming from the actual coaches doing the athletic ‘triage’ in clubs, junior teams, and the like.

Once a young athlete is identified as ‘talented,’ he or she is then, to varying degrees, separated from ‘non-talented’ or ‘less talented’ peers and given access to resources that less promising young athletes will not receive. The initial difference, the symptom of ‘talent’ or ‘promise,’ leads through social and coaching mechanisms to a later difference, elite skill, whether or not the initial difference is organically or developmentally linked to the elite skill that eventually develops in any direct or causal way.

This divergence is represented by the two possible developmental trajectories in the middle register (in red and pink). The blue and green line separating them, I’ve called the ‘cultural “talent” barrier’ because of my natural knack for zippy names. This second version of the diagram focuses on some of the factors that make up, and arise because of, the cultural ‘talent’ barrier.

The cultural ‘talent’ barrier

(c) Greg Downey 2009

The resulting experts will look different than more normal, under-achieving peers. For example, Dan Peterson discusses a recent article using brain scans of golfers in his piece, Tiger’s Brain Is Bigger Than Ours. The original article in PLoS ONE, The Architecture of the Golfer’s Brain, by Jäncke and colleagues (2009), makes two key points: first, that practice time directly correlated with golfers’ expertise (measured by their handicap) and that there was a stepwise quantitative difference in gray brain matter area in sensorimotor and cognitive areas linked to precision swinging (the left dorsal pre-motor and parts of the posterior parietal cortex in right handers). Jäncke et al. write,

the current finding supports the idea that neuroanatomical changes are induced by intensive golf practice…. These data are consistent with the view that the anatomical changes might have occurred at some point after the first 800–3000 practice hours or after a practice impact of more than 310 practice hours per year. In other words, anatomical changes may be induced by decreasing the golf handicap in early training phases to a handicap of approximately 15, whereas further practice, which is evidently necessary to achieve the proficiency of an elite golfer (associated with an average total of 27,000 practicing hours or 1,730 practise hours per year in this study), does not contribute any further to neuroanatomical reorganisation.

A cultural ‘talent’ barrier may be high in a particular sport, then, because of the peculiarities of the neuroanatomical adaptations that have to be made, or because of social and cultural factors that make it appear early promise is necessary to gain later expertise.

If the cultural barrier is low, we would expect that adults assume some kids don’t show promise until later, don’t give too much extra training or expertise to those youngsters with early advantages, and keep a broad segment of the population engaged, even if everyone involved isn’t convinced that they will be very good. Given this ‘low barrier’ condition, we would anticipate movement of individuals back and forth across the ‘talent’ barrier, less anxiety about being left off of a select team or failing at a try-out, and encouragement to keep trying as well as widespread opportunities to train systematically.

The promotion of ‘talent identification’ early in athletes’ development could theoretically lead the cultural ‘talent’ barrier to grow less permeable: those identified young would be given much greater opportunities for increasing expertise with very real physiological and neurological consequences. ‘Untalented’ individuals would also be clearly identified with corresponding impact on their development. The best coaching resources would be put at the disposal of a small group. If the young people believed their diagnoses, and then trained (or ceased to train) based on these assessments, the designation would profoundly affect the extraordinary motivation needed to undergo 10,000 hours of deliberate practice.

To put it simply, talent identification can become a self-fulfilling prophecy, pernicious because it widens the gap between those who are ‘promising’ from those who do not show early signs of ‘talent,’ even if those alleged markers of talent do not actually feed directly into the final expert result. That is, talent identification may focus on variables that are irrelevant for future accomplishment and yet still produce both enormous disparity and achievement in those labelled ‘talented,’ although the labelling is empirically incorrect (outside of the socio-cultural coaching system itself).

What may be a small initial difference, even a neurological advantage, can be compounded and exacerbated in many cases by the culturally-based perception that the small initial difference represents ‘talent,’ some innate superiority waiting to reach fruition. Once a person is identified as ‘talented,’ the socio-cultural mechanisms around sport that embrace and seek to develop that talent, to varying degrees fix that early diagnosis by transforming it into a distinctive developmental niche. In part, I take as evidence of this the well researched observation that children who are older for their age brackets are more likely to ‘excel’ at sports and be considered talented controlling for other factors; the slight differences—and sometimes not-so-slight differences—arising from less than 12 months increased physical maturity lead to a self-fulfilling bias in the older athletes’ favour (see the discussion of this research in A Star Is Made by Stephen J. Dubner and Steven D. Levitt, with links to original papers at Freakonomics in the Times Magazine:
A Star Is Made).

Given Ericsson’s work on the effects of deliberate practice, including the neurological and physiological consequences, whichever trait is singled out as symptomatic of ‘promise’ will have an effect as a gatekeeper to resources or provocation for support mechanisms that encourage the development of skill. For example, if talent scouts looking at junior tennis players focused primarily on the velocity of a young player’s serve, those who matured fastest, becoming the biggest, would tend to be classified as ‘talented.’ Ironically, systematic study of junior tennis players who achieve success actually shows that they tend to be under-sized as junior players, catching up to their peers later, just the opposite of one potential way to identify ‘talent.’ Likewise, Helsen and colleagues (2000) suggest that much of what is identified as ‘talent’ in junior soccer may be physical precocity rather than a permanent advantage in dexterity, body control, or skill. Or from my earlier example, juggling ability in soccer may (or may not) be linked to later expertise; it may even be a secondary indicator, a symptom of a young athlete having the motivation or perceptual skills necessary to learn more important skills. Juggling would correlate well with success even though the skill itself might be irrelevant to later accomplishment (and the time spent on it, in some sense, wasted).

The initial advantage may be surmountable in neurological terms, but buttressed by cultural expectations. Draganski and colleagues (2004), for example, found neurological changes in adults who trained to juggle. As two of the authors later reviewed (Draganski and May 2008), these findings are part of an emerging recognition in brain sciences that plasticity exists in the adult brain, outside of what were once believed to be critical developmental windows. As a cultural belief, however, the idea that the adult brain cannot change was (and is) part of a ‘talent’ barrier, discouraging late-developers from believing that they have a chance to develop skill.

Dan Peterson in Science Daily discusses How to Pick Athletic Superstars at Age 1, and comes to similar conclusions: although genetic tests for ACTN3 variations met with initial excitement, as variants of the gene have sometimes been linked to the prevalence of fast-twitch and slow-twitch muscle fibres, follow-up research has made the excitement about ACTN3 seem a bit premature. Predicting future athletic greatness on the basis of a genetic marker, or even on the basis of early achievement, runs contrary to basic research about how expertise emerges, including the extraordinary motivation, support, and commitment that development takes.

Through circuitous mechanisms of ‘talent,’ however, differences among novices can lead to elite abilities, but not because those elite abilities are already present, inchoate in the novice. Paradoxically, for some athletes, early rejection or frustration can help provide the stimulus for determined training and self-development. By the time the developmental trajectory reaches elite levels of refinement, extracting the effects of training, social selection, positive (and negative) reinforcement through affirmation (or discouragement), and self-fulfilling prophecy, is impossible.

The future research

The research project that I am working on right now, the one I’m writing grant applications for and doing all that sort of time-consuming, hair-pulling sort of work, includes work on cultural differences in the identification and development of ‘talent.’ That is, I suspect the traits that get a young person identified as ‘talented’ vary across cultural contexts.

9-year-old Fotu Luani, 85 kg

Here’s a case where the initial variable that may make a child appear ‘talented’ or ‘not talented’—precocity of child development and onset of growth spurt—may or may not be linked to a later relevant physical advantage in the sport. Not only is bigger not necessarily better in rugby, but a lot of late developers catch up to and bypass their bigger peers. Polynesians make up something like 40% of all professional rugby league athletes in Australia, but they occupy a range of positions, demonstrating that their size is not necessarily always the key foundation for their elite-level skills. Moreover, if the nervous system is faster developing in boys with early growth, the extreme plasticity of adolescence, when so much coaching work can be done on skill development, might end more quickly (this is purely a hypothesis). But if small boys are chased out of the sport for fear of injury, the cultural barrier to developing their skill is quite great, but one that could be surmounted by a number of simple mechanisms (such as weight-graded teams or lower contact variants of the sport to encourage skill development).

In another rugby-related example, some sporting systems are quite selective at an early age. I’ve watched my nephew move through multiple layers of ‘select’ or ‘representative’ squads, being chosen to play for his quarter of the city, for Sydney ‘city’ against New South Wales ‘country,’ for our state against other states, and then for Australia, all before the age of sixteen. For a person making it through this extraordinary system, the affirmation is enormous and the accumulation of access to coaching resources at each stage of this process helps to crystallize and widen any initial advantage the successful young athlete might have possessed. In contrast, the vast majority of rugby-playing hopefuls have had to face rejection at some stage of this process, told to ‘keep trying for next year,’ but given the implicit message that they are inadequate already at an age when most of them are far from physically mature.

Other sporting systems may not be nearly as selective. I marvel at extraordinary participation levels for men in rugby in New Zealand; even at the relatively senior age of 35+, participation in full-contact rugby is 11% (see SPARC 2001). Even more strikingly ‘democratic’ than the New Zealand case are some of the figures I have heard for participation in Australian-rules football in the Tiwi Islands, where it is rumoured that 40% of the whole population is involved in playing.

Although I have yet to really do the ethnographic fieldwork I need to put this in perspective, I have a strong sense that the ‘club’ approach to rugby in New Zealand contrasts with the severely age-graded selective environment I saw in Sydney, or in many sports in the United States. In the US the collegiate sporting system simultaneously encourages elite athletes to concentrate even harder (with scholarships at stake) while it demotivates many people from continuing to participate (for example, among those who do not go to university).

I suspect that ideas about ‘talent’ and socio-cultural arrangements of childhood sport affect each other. The rise of select teams or the contrary development of more widespread participation in sports can both help convince people that talent is either rare or widespread, with real physiological consequences for how the initial differences among children either become exaggerated or mitigated by training techniques.

Although this is only one dimension of the project, I think it’s one that has clear applications in youth sport and other social mechanisms that produce expertise over time. Clearly, there are initial differences in ability, some of which may be due to innate advantages in some individuals. But I suspect that a cultural system designed to identify ‘talent’ early and concentrate coaching resources on those with early promise can actually make the expert skill more rare as it demotivates those who might develop expert skill without the early advantage or mature more slowly. Rigorous talent identification may produce a handful of highly skilled individuals, but it may concentrate training resources so much that it makes the overall skill more rare than in a more open developmental program.

Conclusion

In summary, although I agree with Ericsson that expert performance clearly requires extraordinary efforts at development, strong coaching, and intense motivation, I don’t want to underestimate the importance in this process of very early differences in ability. Far from being irrelevant, early differences may contribute to future expertise, as they are compounded, exaggerated, or even leveraged into entirely unrelated abilities. If resources are allocated depending upon early diagnosis of ‘talent,’ then talent matters. The more a society believes in ‘talent,’ the more likely it is to become a reality, and the greater disparity we are likely to find between those designated as promising from those who don’t show early promise.

Given this approach to ‘talent,’ I don’t think it can be divided into a portion that is ‘innate’ and another that is ‘learned’ or ‘developed.’ Talent is a difference that makes a difference, either because it lays the foundation for future skill or because it unlocks access to socio-cultural structures that help a person to generate greater skill, but more likely because it does both. It’s not easy to separate those differences that are ‘foundations’ from those that are more social ‘keys.’

Part of the problem with the idea of ‘talent’ is that it discourages researchers from looking more closely at which developmental factors might produce the initial difference that gets compounded or what makes some people respond to one type of training when others do not. ‘Talent’ becomes a garbage variable, a way of explaining the unknown without really studying it more closely. ‘Talent’ locates all the cause for differential outcome in the individual, making it very hard to conceive of any other way to increase expertise than to look harder for ‘talent’ and spend more on developing it when it’s identified. In some cases, ‘talent’ may be a match between a distinctive pattern of motor control or style of perceptual processing with the task at an early stage or the selection structure, one that, if we understood it better, we could compensate for in others or even coach its development better.

Although it might be possible to develop more precise tools for identifying talent, discarding cultural concepts that are misleading or just wrong about which sorts of early developmental difference are actually predictors of future success, I don’t think that this is the best strategy. Ericsson’s research suggests very strongly that what is really in short supply in the cultivation of expert performance is not initial ability, but rather expert coaching and motivation to continually develop greater skill. In some ways, the popular versions of Ericsson’s work may help to fire more motivation; I’m hoping that some of the other dimensions of my research might help address the shortage of expert coaching, but I’ll save that discussion to another post.

Credits:
Thanks to Dan Peterson at Science Daily and Sports Are 80 Percent Mental for continually providing excellent discussions of the implications of sports science research. Thanks also to John Sutton and the folks at the Macquarie Centre for Cognitive Science, for their feedback and thoughts on the project.

If you’re interested in the work of K. Anders Ericsson, definitely check out his website and publications, or consider reading one of the popular books based on his work.

For more on the controversy about large boys in junior rugby, see Is Fotu, 9 and 85kg, too big for his teammates’ boots? at ourfootyteam.com

Please cite this materially responsibly as this is, like everything on Neuroanthropology.net, an intellectual labour of love for the authors.

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References

Abernethy, B. 1987. Selective attention in fast ball sports. II. Expert-novice differences. Australian Journal of Science and Medicine in Sports 19(4): 7–16. (abstract)

Colvin, Geoff. 2008. Talent Is Overrated: What Really Separates World Class Performers from Everybody Else. Portfolio.

Coyle, Daniel. 2009. The Talent Code: Greatness Isn’t Born. It’s Grown. Here’s How. Random House.

Draganski, B., C. Gaser, V. Busch, G. Schuierer, U. Bogdahn, and A. May. 2004. Neuroplasticity: Changes in grey matter induced by training. Nature 427(6972): 311–312. doi:10.1038/427311a

Draganski, B., and A. May. 2008. Training-induced structural changes in the adult human brain. Behavioural Brain Research 192:137-142.

Entine, Jon. 2001. Taboo: Why Black Athletes Dominate Sports and Why We’re Afraid to Talk About It. New York: Public Affairs.

Ericsson K. Anders, Ralf Th. Krampe, and Clemens Tesch-Römer. 1993. The role of deliberate practice in the acquisition of expert performance. Psychological Review 100(3): 363–406. (pdf available here)

Ericsson, K. A., and A. C. Lehmann. 1996. Expert and Exceptional Performance: Evidence of Maximal Adaptation to Task Constraints. Annual Review of Psychology 47: 273-305. (pdf available here)

Ericsson, K. Anders, Michael J. Prietula, and Edward T. Cokely. 2007. The Making of an Expert. Harvard Business Review 85:114-121. doi 10.1225/R0707J online version available here.

Helsen, W. F., N. J. Hodges, J. Van Winckel and J. L. Starke. 2000. The roles of talent, physical precocity and practice in the development of soccer expertise. Journal of Sports Sciences 18: 727-736.

Houghton, Philip. 1990. The adaptive significance of Polynesian body form. Annals of Human Biology 17(1): 19-32. (abstract)

Jäncke, Lutz, Susan Koeneke, Ariana Hoppe, Christina Rominger, and Jürgen Hänggi. 2009. The Architecture of the Golfer’s Brain. PLoS ONE 4(3): e4785. doi:10.1371/journal.pone.0004785

Regnier G, Salmela J, and Russell SJ. 1994. Talent detection and development in sports. In Singer R. N., Murphey M., Tennant L. K., eds. Handbook of Research on Sport Psychology. Pp. 290–313. London/New York: Macmillan.

SPARC (Sport & Recreation New Zealand/IHI Aotearoa). 2001. SPARC Facts: Rugby Union. Information from Sport & Recreation New Zealand’s (SPARC) 1997/98, 1998/99 & 2000/01 Sport & Physical Activity Surveys. Available at: www.sparc.org.nz/research-policy/participation-in-sport

Starkes JL, Deakin J. 1984. Perception in sport: a cognitive approach to skilled performance. In Cognitive Sport Psychology, ed. WF Straub, JM Williams, pp. 115–28. Lansing, NY: Sport Sci. Assoc.

Taylor, Peter. 2001. Distributed Agency within Intersecting Ecological, Social, and Scientific Processes. In Cycles of Contingency: Developmental Systems and Evolution. Susan Oyama, Paul E. Griffiths, and Russell D. Gray, eds. Pp. 315-332. Cambridge, Mass: MIT Press.

Gary Evans and Michelle Shamberg recently published a PNAS paper, Childhood Poverty, Chronic Stress and Working Memory (pdf). Here’s the abstract:

The income–achievement gap is a formidable societal problem, but little is known about either neurocognitive or biological mechanisms that might account for income-related deficits in academic achievement. We show that childhood poverty is inversely related to working memory in young adults. Furthermore, this prospective relationship is mediated by elevated chronic stress during childhood. Chronic stress is measured by allostatic load, a biological marker of cumulative wear and tear on the body that is caused by the mobilization of multiple physiological systems in response to chronic environmental demands.

The Evans and Shamberg paper has gotten prominent media attention. Over at Wired, Poverty Goes Straight to the Brain got an enormous number of diggs. Brandon Keim’s opening lines are, “Growing up poor isn’t merely hard on kids. It might also be bad for their brains. A long-term study of cognitive development in lower- and middle-class students found strong links between childhood poverty, physiological stress and adult memory.”

Jonah Lehrer wrote Stress, Poverty, Working Memory which includes this effective summary, “The scientists uncovered a statistically significant link: the longer children had been poor, the worse their working memory. Furthermore, levels of chronic stress seemed to be the causal factor.”

The Economist also covered the PNAS paper, and wrote about how stress does its damage. “Stress also suppresses the generation of new nerve cells in the brain, and causes the ‘remodelling’ of existing ones. Most significantly of all, it shrinks the volume of the prefrontal cortex and the hippocampus. These are the parts of the brain most closely associated with working memory. Children with stressed lives, then, find it harder to learn.”

Lehrer, in his 2006 Seed article Reinvention of the Self about the work of primatologist/psychologist Elizabeth Gould, presents us with one of the main “take home” messages of work that links stress, poverty and development:

The social implications of this research are staggering. If boring environments, stressful noises, and the primate’s particular slot in the dominance hierarchy all shape the architecture of the brain—and Gould’s team has shown that they do—then the playing field isn’t level. Poverty and stress aren’t just an idea: they are an anatomy. Some brains never even have a chance.

This work by Evans and Shamberg is important, another step forward in showing that inequality matters and that it works through specific processes that directly shape individual development and function. But this line of work also has some limitations because it lacks a critical side – do we really need 500+ diggs to know that poverty is bad?

One piece that raises important critical questions is Michelle Chen’s The Impoverished Mind over at RaceWire. She writes, “Put simply, if your childhood is consumed by a constant struggle to survive day-to-day, your brain is less likely to develop the abilities you need to succeed tomorrow, compared to your economically better-off peers. This is empirical evidence that nature-versus-nurture is not an either or, but that social factors interplay with the brain’s biology throughout life.”

Then Chen goes further:

Empirical research on the connection between poverty and intellectual development can cut both ways—leading some to write off poverty as biological destiny, and others to look deeper into missed opportunities to lift youth over economic barriers… The policy implications for the growing body of achievement-gap research are [also] fraught with the same tensions straining other civil rights issues: how do you emphasize systemic impediments without pathologizing communities and cultures? How do you make the case for structural inequalities without fueling reactionary accusations of victimology?

Some of my own concerns focus on the biology side. Take a section from Lehrer’s Seed piece, “From the brain’s perspective, stress is primarily signaled by an increase in the bloodstream of a class of steroid called glucocorticoids, which put the body on a heightened state of alert. But glucocorticoids can have one nasty side-effect: They are toxic for the brain.”

Here stress “from the brain’s perspective” is taken to be entirely physiological. In general, stress is often made out to be psychobiological, an internal and individual state largely shaped by “fight-or-flight” ideas about activation of the stress system. As I’ve argued before, stress is actively social and intimately meaningful. These are not outside the perspective of the brain – they become part of how the brain functions. In this way stress becomes a process and not simply a state, either of mind or body.

But the more problematic area is that the brain becomes a fetish: Oh, see the neuroanatomical changes there, this stuff about poverty being bad for you must be true…

Recall the opening of the Wired piece, “Growing up poor isn’t merely hard on kids. It might also be bad for their brains.” Here children become a mere token, placed to one side in favor of our new marker of individual self, the brain.

While I advocate for the role that brain processes can play in social theory, the sword cuts both ways. Referencing the brain as central mediator of poverty hides the truth, and distorts our understanding. To take a more extreme example to illustrate the same point, it’s like saying that slavery is both harmful to people and morally wrong because it impacts brains.

The brain becomes rather like property in this approach, something a person possesses and that poverty – somehow separate from the person, a naturalized thing that causes stress – negatively impacts. But that approach avoids the radical implications here on both sides.

First, that poverty literally can be anatomy, which means we need to fundamentally rethink the token brain metaphor and actual functioning of the brain. Second, that taking the neuroscience results seriously means that social environments, in all their complexity, become as important as any brain function. Indeed, many would argue that in this case, social inequality is more important than brain function, since it is what is driving the system.

To bring a critical approach into better view, I have found it useful at times to watch the following video of Paul Gilroy speaking on slavery, ignorance, and property. Rather than just working memory, Gilroy brings the larger picture into focus: “[We often] think that ignorance is a kind of vacuum into which truth can get stuffed at the right moment. And I think that we need a better account of the politics and the meaning of ignorance in our time than that. We need to think about ignorance in a different way. We need to think about ignorance as a systematic product.”

By excessively focusing only on the brain, we miss doing what Gilroy advocates for truly understanding ignorance and inequality — engaging in “critique of life as property, of humanity as property, of history as property.” We need to move beyond seeing the brain as a physical thing, similar to a book we can reference to say poverty is bad or a kind of currency that we carry around and barter to show off we’re smart and current. Or worse, something to manipulate through pharmaceuticals and computers and emerging types of neuroengineering. As Gilroy says, we need to become more critical while also realizing the dignity and meaning of people’s lives.