Pets, health and our extended phenotype

There’s a fun piece in The New York Times on The Healing Power of Dogs that discusses a wide range of health effects linked to pet ownership. The article briefly discusses a range of research that has linked pet ownership to health benefits. For example:

One Japanese study found pet owners made 30 percent fewer visits to doctors. A Melbourne study of 6,000 people showed that owners of dogs and other pets had lower cholesterol, blood pressure and heart attack risk compared with people who didn’t have pets. Obviously, the better health of pet owners could be explained by a variety of factors, but many experts believe companion animals improve health at least in part by lowering stress.

This research is fascinating in its own right, especially for a person who’s only recently started to live around animals… a lot of animals (at last count, 8 horses, 1 horse expecting a foal, 2 cats, 2 dogs, innumerable wild birds, kangaroos and wallabies all wandering onto the property). I’ve noticed a huge difference in my health and mood since the change, but it’s hard to separate the effects of having Basil and Roxy (the dogs), Glitz and Glam (the cats), or the bigger monkeys around (the horses). But the research discussed also touches on two issues that I think are of particular importance to those of us interested in neuroanthropology and the biology-culture interface.

Edited version
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Mice brains on stress

Blogging on Peer-Reviewed ResearchIn February 2006, a research team at University of Texas and Tufts University published a piece in Science on how experience could modify the structures in the brain that affect the production of dopamine through brain-derived neurotrophic factor (BDNF) (abstract here). The research team used ‘social defeat’ to explore ‘the neurobiological mechanisms through which psychosocial experience alters the activity of the mesolimbic dopamine pathway’; in other words, the malleable system that can induce structural changes in the brains of mice in response to persistent patterns of social interaction.The abstract, while a little thick, suggests all sorts of intriguing possibilities:

Mice experiencing repeated aggression develop a long-lasting aversion to social contact, which can be normalized by chronic, but not acute, administration of antidepressant. Using viral-mediated, mesolimbic dopamine pathway–specific knockdown of brain-derived neurotrophic factor (BDNF), we showed that BDNF is required for the development of this experience-dependent social aversion. Gene profiling in the nucleus accumbens indicates that local knockdown of BDNF obliterates most of the effects of repeated aggression on gene expression within this circuit, with similar effects being produced by chronic treatment with antidepressant. These results establish an essential role for BDNF in mediating long-term neural and behavioral plasticity in response to aversive social experiences.  

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Loneliness and Health: Experience, Stress, and Genetics

Blogging on Peer-Reviewed ResearchFeeling lonely?  Well, that might make you sick.  The mechanism?  Well, here’s the surprise.  Patterns of genetic expression.

 Here’s the press release from Genome Biology, “People who experience chronically high levels of loneliness show gene-expression patterns that differ markedly from those of people who don’t feel lonely.”  The study’s lead author, Steven Cole, notes: “In this study, changes in immune cell gene expression were specifically linked to the subjective experience of social distance.  The differences we observed were independent of other known risk factors for inflammation, such as health status, age, weight, and medication use. The changes were even independent of the objective size of a person’s social network. What counts, at the level of gene expression, is not how many people you know, it’s how many you feel really close to over time.”    Continue reading “Loneliness and Health: Experience, Stress, and Genetics”

On Stress-Part Two-Blakey

Blogging on Peer-Reviewed ResearchBy Daniel Lende 

The other night, my two year old daughter complained with a sleepy vehemence, then turned to my wife for comfort (yes, we are co-sleepers!).  She had been sick, unable to sleep well, and she sought out her mother for comfort and soothing.  It wasn’t that my daughter was physically stressed, but that her little mind seemed to get ahead of herself.  The terrible things bothering her?  Suddenly they are all right because of Mamá. 

What does this have to do with the fight-or-flight reaction?  Very little.  But anyone who’s tried to deal with a screaming baby knows that such a thing is very stressful for everyone involved.  And that’s the point.  Stress does not sit so easily into the category we imagine for it.  When my daughter screams, I feel my blood pressure rise and a lack of control if I am unable to soothe her.  Alternatively, calming her calms me.  These sorts of experiences do not fit easily into the stressor/stress reaction dichotomy covered in yesterday’s post on Robert Sapolsky.  But I had not really thought about it that way until I recently read the work of Michael Blakey, professor of anthropology at William & Mary. 

In his chapter “Beyond European Enlightenment,” Blakey opens with a discussion of how naturalism leads into ecological and evolutionary “explanations” that lie explicitly outside the social realm as well as to sexual, racial and genetic determinism (“natural” causes or differences, hence we just have to accept the present state of affairs).  Blakey is not against the documenting of human variation that good ecological or human biology research can highlight, say between a certain type of environment and a certain body type.  However, he is against this approach becoming the core focus of a discipline (say, biological anthropology) and quite aware of the dangers that the projection of biological explanations into the social realm plays in the communications and politics of a public anthropology. 

As he writes, “Naturalism as it informs empirical methods shows the human element in data analysis as contaminating, deviating from ultimate truth.  Culture, therefore, becomes a thing to be purged (or denied) in apprehension of legitimate truth (382).”  He sees the logical extension of such a view as: “The proper order of human life according to this view is to be found outside human society.  Whether the method is belief in gospel or systematic evidence, religion and natural science obtain an allure of being able to reveal knowledge from beyond human agency (382).”  

Continue reading “On Stress-Part Two-Blakey”

On Stress-Part One-Sapolsky

Blogging on Peer-Reviewed ResearchBy Daniel Lende 

In my research in Colombia, I dealt with teenagers across the spectrum—kids from good families with futures they could see, kids who had gone through more shit than most people will see in their lifetimes.  One kid, let’s call him Rafa, came from a small town outside of Bogotá, his family not in the best circumstances.  In my talking with Rafa, he dwelled on the horrible process of social exclusion that he went through—first the whispers and bad looks, then problems at school, the violence and rejection at home, and the final demand from a coalition of men, powerful and dangerous men, that he simply leave.  Sure, Rafa was no saint himself, but that’s not the point.  The dwelling on what other people did, that was the hard thing in his life when I met him.  He didn’t deal with that in the best way either, finding support in hate-filled ideologies and drug-using friends.  I don’t think many adults had ever just taken the time to talk with him, to get to know him.  And he still got kicked out of the school, a school that took in kids that had had problems elsewhere, during that year I knew him.  I remember that administrative meeting well.  No teacher spoke up for Rafa, and I didn’t count as the anthropologist.  So Rafa ran out of chances once again.  Except that is the wrong expression—he ran into chances that bopped him around like the ball on a roulette wheel, only to end up on zero.  It was people that did that. 

So that’s the ethnographic moment. 

Let’s turn to some other research. Robert Sapolsky’s work is widely known.  His best-selling book, Why Zebras Don’t Get Ulcers, is now in its third edition, and his Perspectives piece in Science has been cited 485 times according to Google Scholar.  He is acclaimed in biological anthropology circles because of his concern with mechanism, the elegance of his naturalistic studies with baboons in Kenya, and his consideration of the heavy stress-related costs of inequality.  The back cover of the Zebras book summarizes the core argument of the book, “When we worry or experience stress, our body turns on the same physiological responses that an animal does, but we usually do not turn off the stress-response in the same way—through fighting, fleeing, or other quick actions.  Over time, this chronic activation of the stress-response can make us literally sick.” 

Michael Blakey is better known for his critical archaeology work and his leadership with the New York African Burial Ground.  The work I will discuss, Blakey’s chapter “Beyond European Enlightenment” in the edited volume Building a New Biocultural Synthesis, has been cited 5 times according to Google Scholar.  His earlier chapter “Psychophysiological Stress as an Indicator of Disorder in Industrial Society” in the book Diagnosing America: Anthropology and Public Engagement has been cited all of once.  But it is Blakey’s work that has turned my mind around in the past few days in ways that Sapolsky never quite has.  These two posts will explore why the blurb on Sapolsky’s book is wrong and why that is important to what neuroanthropology can do. 

Today I will start with Sapolsky’s recent Science review “The Influence of Social Hierarchy on Primate Health.”  The article begins with the familiar “socioeconomic gradient,” where the “stepwise descent in socioeconomic status (SES) predicts increased risks of cardiovascular, respiratory, rheumatoid, and psychiatric diseases; low birth weight; infant mortality; and mortality from all causes.”  Sapolsky then provides a traditional review of the stress response—there are physical and psychosocial stressors, and both activate an “array of endocrine and neural adaptations.”  These adaptations are generally mobilized in response to challenges to homeostasis.  In response to “an acute physical challenge,” the stress response works through mobilizing energy, increasing cardiovascular tone, and inhibiting unessential anabolism; in other words, the classic “fight-or-flight” framing of stress.  Chronic activation, particular by chronic psychosocial stressors, can increase or worsen health problems ranging from “hypertension, atherosclerosis, insulin-resistant diabetes, immune suppression, reproductive impairments, and affective disorders.” 

Continue reading “On Stress-Part One-Sapolsky”

Neuroanthropology and Everyday Design

Today’s article by John Tierney, Why Nobody Likes a Smart Machine, from the Tierney Lab illustrates several points that neuroanthropologists should pay attention to.  It’s about the work of Donald Norman, best known for his book “The Design of Everyday Things,” and his analyses for why modern technology often frustrates people so much.  (By the way, I just bought my wife one of those picture frames mentioned in the article for Christmas—ah, a bundle of frustrating joy.)  So, in the course of the article, Tierney and Norman mention four different aspects of how we relate successfully or unsuccessfully to machines (and, from my point of view, much of the world).  They are: 

-Predictability (the pedestrian who keeps walking so the bicyclist easily avoids him)

-Being Understandable (human-sized signals like the whistle from a tea kettle; having an intuitive feel—read, culturally modeled, metaphorically presented, and visually and tactically available)

-Control (the clever solution to wrapping a wet paper towel around the electronic sensor on the bathroom faucet)

-Feeling Helpless (computerized shades that worked on their own without being able to be locally manipulated) 

These factors are tied up into three related phenomena—evolution, culture, and the brain—at the core of neuroanthropology.  In this case, they are (1) achieving behavioral success in often stochastic evolutionary environments, where acting on environmental information in goal-directed ways often led to good things (like food) (the evolutionary problem), (2) how culture built off human tendencies—our ability to apply learned, controllable, regular solutions in novel ways (but not badly designed ways—hence the problems with some technology) (the cultural side), and (3) the brain systems that handle stress, where unpredictable, uncontrollable stressors are the ones that make us react the most (the brain).  Hence, the predictable line of frustration, anger, and then simply giving up and making do the best you can with the present situation. 

Plus Norman did participant observation and interviewing as his methodological approach!  If you want to talk more, just email me at dlende@nd.edu.  Best, Daniel Lende