neuroanthropology and race- getting it straight

This is a response to the post by Doublehelix re: races and human biology emerging out of Daniel Lende’s post on IQ and environment..  The issue of human biological units and intelligence/cognition is very old and seems to keep appearing despite serious problems in the way the positions are most commonly framed.  This is a core factor in discussing neuroanthropology.  It is extremely important to realize that if you are going to use race as a biological unit then you must define it!  I would like to ask Doublehelix to present a definition of human groups that are consistently identifiable by a set of biological characteristics that separates them from other such groups.  There is no argument that human populations, both regional and meta-populations, vary in a number of biological characteristics.  However, are these evolutionary units or of evolutionary relevance?  Are there functional differences across human groups (once you are able to define what you mean by group).

Discovering shared frequencies of alleles in regional and meta-populations is expected via standard models of gene flow.  However, globally humans break the standard models of gene flow by their very low inter-population variation relative to species wide variation (not to discount the reality of a lot of variation across the geographical distribution of our species and huge inter-individual variation)…Doublehelix uses the Risch and other  articles to refute this, but ignores all of the work by many, many others (see below for a sample) that discuss and explain why one might see clustering of some allelic variation as associated with geography, and what that might or might not mean in an evolutionary sense. We are well beyond Lewontin 1972…  Allele frequency clusters are not races or even biological units…the association of function with specific distributions of frequency patterns of various alleles can and should be done, but has to be done with extreme care and we must play by the biological rule book.  If you are comparing biological units they must be biologically, not socially, defined.

The statement “As for the notion that race is not supported by biology, I ask: Why do races differ so profoundly in so many different characteristics, such as IQ, lactose tolerance, the resistance to malaria, skin and hair color, the effectiveness of certain drugs?” is rooted in a severe simplification…for example, lactase production is widespread across 100s of human populations with peaks in Northern European, east African and even middle eastern populations…so what does it say about race?  Malaria resistance via one of the 5 sickle cell mutations occurs with high frequencies in West Africa, but also South West Asia and the Middle East?  What race is that?   Hair color ands type are widely distributed…but not markers of unity…for example if having tight curly black hair unified groups then populations in Papua New Guinea and Nigeria would be linked…they are not.  As for drug differences, this is a very important and complex area of investigation where we actually see some amazing integration of social, physiological and contextual patterns (see recent BiDil research) but not clear patterning of socially defined races as showing any specific identifiable bio-based markers.

 

So for neuroanthropology—we are always going to be tied to a historical context of trying to demonstrate differences between social races, but the terrific opportunity here (thanks to Greg and Daniel) is to break out of a dichotomy of nature/nurture and think out loud about the real processes and patterns extant in humans (individuals, groups, societies, etc…).  Once we leave behind the notion of either “biology” or “society/culture” having more or less agency and try to look at integrative systems of development, actuation, emergent properties and how things might actually function (at physiological, behavioral, and genomic levels) then we can attempt to link these facets across levels and contexts in an evolutionary sense.  This is very complicated and difficult but we are at a place in time and accumulated scientific knowledge where we can at least try.  However, we must leave some of our historical roots to do so.  I urge readers here to go to the AAA race site for current understandings and issues in the science and anthropology of race (http://www.understandingrace.org/home.html)

   

Kittles, R. A., and Weiss, K. M. (2003). Race, genes and ancestry: Implications for defining disease risk.  Annual Reviews in Humans Genetics 4:33-67.

Peregrine, P. N., Ember, C. R., and Ember, M. (2003). Cross-cultural evaluation of predicted associations between race and behavior.  Evolution and Human Behavior 24:357-364.

Relethford, J. H. (2002). Apportionment of global human genetic diversity based on craniometrics and skin color.  American Journal of Physical Anthropology 118:393-398.

Templeton, A. (1999).  Human races: A genetic and evolutionary perspective. American Anthropologist 100:632-650.

Templeton, A. R. (2005) Haplotype trees and modern human origins. Yearbook of Physical Anthropology 48:33-59.

Weiss, K. M. (1998).  Coming to terms with human variation.  Annual Reviews in Anthropology 27:273-300.

13 thoughts on “neuroanthropology and race- getting it straight

  1. My definition of race is this: A race is a very large group of slightly inbred H. sapiens, which became that way due to natural selection acting on a geographically isolated population. No one characteristic is sufficient to identify a race as such, but a great many traits can suffice, making race a fuzzy set, not a category.

    However, I am not wed so much to the definition of “race” as I am to the notion that human beings continued to evolve after they left the African continent, which has led to the development of unique physical and cognitive traits in (formerly) geographically isolated populations. This evolutionary process, acting on the brain and body, is partly responsible for the unique cultures that we see distributed around the globe. In other words, culture is biological, and cultural diversity is based on genetic diversity as much as it is based on learning.

  2. Sorry- I’d like to clarify something: A race is a large group of slightly inbred H. sapiens that is genetically and physically distinct. The race became distinct due to natural selection acting on a geographically isolated population…

  3. races are genetically and physically distinct? What characteristics can one use? Can you give an actual example of a race and their “distinct” genetic and physical characteristics?

    Also, it is important to note that humans have been moving in and out of (and around) Africa for eons (see the Templeton 2004 paper I list above). Human gene flow over the last million years or so is extremely complex as are human physical and behavioral adaptations…Of course humans continue to evolve (everywhere) but this does not predict or mandate any racial divisions (as per your definition). To be so, there would have to be very specific selective regimes with concomitant physical and cognitive adaptive patterns tied to, and distinct in, specific human populations. Any data for that?

    As Dobzhansky said
    “As theoretical possibilities, one can envisage that man might be genetically determined as aggressive or submissive, warlike or peaceful, territorial or wanderer, selfish or generous, mean or good. Are any of these possibilities likely to be realized? Would the fixation of any of these dispositions, so that they become uncontrollable urges or drives, increase the adaptiveness of a species which relies on culture for its survival? I believe that the answers to these questions are in the negative” -Theodosius Dobzhansky (1972).

  4. Well, like I said, race is a fuzzy set, defined by a bunch of factors, none of which is predictive. Call me naive, but one way races can be identified is by physiognomy– caucasian, negroid, east asian, etc. I think most people would recognize the archetypical features of each of those fuzzy sets. I’m not sure what the relevance of the Dobzhansky quote is because I am not saying that any race is genetically determined to have any of those traits. Please explain.

    In discussions about this subject around the net, I notice that the burden of proof almost always lies with the side arguing for a role for genes in cognitive/cultural differences between people, including between men and women. Is it the position of neuroanthropologists that there are no genetically-based differences between, say, ethnic groups? Do neuroanthropologists recognize ethnicity (if not race) as a real biological category? Could different ethnic groups evolve to be more or less intelligent?

  5. Ok, this is going a bit in circles. If race is “a fuzzy set, defined by a bunch of factors, none of which is predictive”…then it is meaningless correct? If we cannot use it in a testable format then it is not science.

    “physiognomy” as you use it does not really mean anything in an evolutionary sense. You give the example of caucasian, negroid, east asian…those things are radically different classifications…you probably meant Caucasoid, Negroid, and Mongoloid…however, those archetypes have been repeatedly shown to be faulty as typological categories…culturally defined seeing is not validation. I asked you for a definition of race and in each case you give a generally fuzzy answer with no testable definition. There is 100 years of literature showing the ineptness of such typological categories for humans. Please read some of it. Please visit the AAA Race website.

    Ethnicity is a culturally defined reality… you can have multiple populations making up one ethnicity or multiple ethnicities in one population. So even if one measures physiological differences between ethnicities (say high blood pressure frequencies between USA Black and USA White) it does not mean the categories are biological units, it means that social factors affecting the social units have real physiological impacts!! Which if you remember was really the pint of the original posting by Daniel Lende. By the way there is a terrific set of papers by Lorena Madrigal and others by Lance Gravlee showing this specifically for North American and Caribbean African descendant populations (real differences).

    Of course there are physiological and cognitive variances between individual humans. That is obvious and easily demonstrated (but highly complex and contingent on a myriad of developmental, nutritional, experiential, genetic, etc…factors). There is no contesting that. However, you seem to want to make a case that there are cognitive differences between specific human groups. So, yes, evolutionarily speaking the burden of proof is on you. The basal assumption is that without clear sub-specific or taxonomic differentiation within a species there is no apriori assumption of adaptive differences between clusters of individuals in that species (regardless of how you cluster them). This is not so say that in some areas, on average, individuals might be taller or have redder fur, or whatever….but that this variation is not selectively significant (re: fitness) otherwise the group that had it would be on a distinct evolutionary trajectory form the rest of the species and be identifiable as such.

    So if you want there to be differences in cognitive capabilities between humans groups you must define the groups as testable and scientifically valid units and then demonstrate cognitive patterned differences. People have been trying to do this for two centuries with absolutely no success. Is all you are trying to do is say that some human groups are smarter than others? Even at that level you still have to define the groups, clearly, and show how you are defining cognitive capability.

    This is exactly the kind of overly simplistic typological thinking that this blog is trying to move beyond. The Dobzhansky quote just demonstrates that human adaptive patterns are complex and not so specifically tied to the kinds of hyper-specific local adaptations you proposed. Please at least read some of the articles I suggested and visit the AAA race website to get an idea why what you are proposing is rooted in an outdated typological mode of thinking and to see where real and exciting questions about cognition, human variation, and human evolution being addressed.

    Let me leave you with one last quote from one of the founding fathers of North American Physical (Biological) Anthropology, Sherwood Washburn (from his presidential address to the American Association of Physical Anthropologists):

    “Racism is based on a profound misunderstanding of culture, of learning, and of the biology of the human species”
    (Washburn 1963b:243).

  6. I think one of the main issues that anthropologists in general are sensitive to, and which really contradicts US cultural logic, is that “race” just doesn’t work the same way around the world. Brazil is a great example, where the census forms have over a 100 “races” that one can choose and where one’s race can vary depending on context–who is around you, how much light there is, how tan you are, and other factors. So taking the US form of defining “race,” which comes out of a tradition of enforcing slavery on anyone considered “black” (even if they were mostly “white” in a genetic sense), and applying it to the rest of the world strikes many of us as simply perverse, both in a social and a biological sense.

    Biological anthropologists are in total agreement that there is biological variation, and that this variation can be linked to environmental factors–such as melatonin, cancer rates, and Vitamin D synthesis, or lactose tolerance in the varied groups that have herded for many thousands of years. But the problem is that, taken as a whole, these patterns of variations do not match up even in fuzzy sets–what to do about those problematic Aboriginal populations with blond hair and darker skin, or those problematic European populations with red hair which might be linked back to Neandertals?

    So, we recognize that there are genetically-based differences between populations, and that there are socially-based differences between ethnic/social groups. Where these differences meet is very fuzzy indeed. As I tried to portray in my discussion of IQ, the way to understand these differences is not through categorical thinking but through processual thinking. Brains look the same except for patterns of activation, in genes, in wiring together, in environmental interaction. Could gender play a role in that activation? It surely does. Race in the US? The same. But to jump from that as a research question (let’s find out how–what processes account for those differing patterns) to causation based on a category that does not accurately represent the processes and populations in question, that’s where things get difficult. Given the historical repression of women and minorities, we err on the side of both science (what Agustin cites) and ethics (do no harm is as good a place to start as any). So, I would agree with you, given the science and ethics involved, the burden of proof does lie on the side arguing to extend biological causation into complex social and cultural realms.

  7. Here’s another stab at a definition of race: race is a cluster within gene-space, a set of haplotypes that co-occur with greater frequency than would be expected otherwise. A race is a large, slightly inbred family of people. And an ethnic group, I would postulate, is a subgroup within a race, that is even more inbred than the race itself, and an even tighter cluster within gene-space. So the testable definition of race and ethnicity is one in which sets of genes co-occur with greater frequency than one would expect if they were randomly selected. The Risch article I mentioned somewhere on this blog used an unbiased statistical approach and found that indeed, such clusters do occur — the continent of one’s origin was the most important variable in defining the SNP patterns. I believe the hap-map project is based on the idea that race will be an important variable in predicting which haplotypes co-occur with greater frequency than with others. The researchers of that project are using western european, east asian, and subsaharan african genomes to search for these racial patterns.

  8. It doesn’t work that way. Given the variation in “race” in Brazil, or that in Japan, people once immigrated from Korea but now assimilated genetically in the local population, are still considered an inferior race, you cannot blithely come up with a definition that overlooks the major features that define race in everyday life. That’s bad definition, and bad ethics. The point about ethnicity reveals that–Hispanics are considered an ethnic group in the US, but these are people that can come from an enormous array of geographic populations: European, sub-Saharan African, Amerindian.

  9. Fine. The point is that evolution has acted on (once) geographically isolated populations and led to the development of relatively distinct behavioral traits among those populations. Populations that are now mixed, such as those you describe, are predicted to show statistical heterogeneity in terms of their genomes and behaviors based upon the % of the genome of each formerly isolated group within the individual. The level of analysis that one chooses: racial, ethnic, or the present-day admixture present in some places, such as Japan or the USA, is irrelevant. What is central to my point is that just as evolution has acted in recent history to modify humans appearance, humans have also evolved neurologically. Example: Tay Sachs disease, seen only in Ashkenazi Jews (who have the highest IQ of any culturally defined ethnic group), may be based upon the selective advantage conferred to heterozygotes of the HEXA gene on dendrite development.

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  12. “Discovering shared frequencies of alleles in regional and meta-populations is expected via standard models of gene flow. However, globally humans break the standard models of gene flow by their very low inter-population variation relative to species wide variation.”

    This sounds like Lewontin’s fallacy. It’s often pointed that there is low inter-population genetic variation. Based on this, it is argued that (genetically mediated) between population phenotypic variation must also be low. Lewontin, and almost everyone since him, failed to mention that the variation between individuals between populations is actually quite high.
    (Assume a between population variability of 15%. Assume a within population variability of 85%, 42.5 which is between individual and (roughly) 42.5 which is within individual (diploidity); calculate variability between individuals of different populations (15/42.5) = 35%. That would predict substantial phenotypic differences.

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