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How do we define populations?


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Academic journals often solicit book reviews from faculty. Faculty get a publication and a free book out of it, so it’s especially worth it for those of us clawing our way up the tenure track. Last year I reviewed Wenda Trevathan’s Ancient Bodies, Modern Lives: How Evolution has Shaped Women’s Health, and the issue finally came out yesterday (if you cannot access the issue for free and want to read my review, it is legal to email the author of the article for a copy. Hint, hint).

Overall, I loved the book, and think it’s great for anyone with an interest in women’s health or evolutionary medicine. So yes, I think you should buy it.

But Trevathan was provocative in a few places. In particular, Trevathan uses the terms health-rich and health-poor to describe populations, when the more common terms are often industrial and traditional, or western and non-western. Recently, I have even seen some populations referred to as post-industrial, since what many people are doing in places like the US are now different from industry and manufacturing.

There are some good reasons to try and make these distinctions between human populations. People who live as foragers, as agriculturalists, people who live in rural areas and in cities all get their food differently (hunting it, growing it, or buying it) and this has a profound impact on lifestyle. Many people think that understanding the different lifestyles and health of people who live differently will help us understand some of the big questions of human evolution. What selection pressures led to humans putting on fat as easily as we do? How is it that we can survive on just about any diet? How much physical activity was normal for early humans?

Making these distinctions also help those of us in countries like the United States figure out why we are seeing an increase in some health problems, like diabetes, obesity, cardiovascular disease and cancer. Making comparisons between those of us whose work consists of typing at a computer, harvesting barley or slowly stalking a giraffe help us understand modern diseases better than saying that Americans eat too much. There is something about the transition to sedentary jobs, to energy dense foods, something about the huge changes in the composition of our diets and how we live from day to day that needs to be better understood. And then we need to figure out what changes we could realistically implement in our society to change our health.

But are these the right distinctions to make? Trevathan is referring in part to access to health care when she uses terms health-rich and health-poor. But are Americans health-rich? We do a good job with childhood illness, with vaccinations, and with treatable or preventable illness, and with sanitation and clean water. We certainly have a lot that we take for granted.

But we have a high rate of premature babies, low birth weight babies, birth complications and maternal and infant mortality compared to other developed nations, not to mention the other health concerns I described above. So among the health-rich nations, if we were to use Trevathan’s terms, we are health-poor when it comes to maternal and metabolic health.

I also can’t help but think of how heterogeneous, or variable, health and health access is within the United States. Many low income women get little to no prenatal care. Race is a major determinant not only of access to health care, but health problems, homicide, addiction and other issues, based on discrimination and internalized racism.

It doesn’t make sense to put all the blame on Trevathan’s terms. Post-industrial/industrial/traditional have their own sets of problems, as do western/non-western. Trevathan is simply trying to find a better terms for the same old categories. So how do we define these different populations? And can we find better words for them?

Part of the point of anthropology is to try and understand the causes and consequences of human variation. One of the problems here is that we are trying to bin all human kind into only two or three categories. Where do we draw the line, and how do we draw it? Because wherever it gets drawn we’ll have to be comfortable with the variation we are ignoring in order to do it. If we bin people into any of these groupings, are we just making the best of a bad situation, relying too much on old dichotomies, or doing our field a disservice?

What kind of terms do you think we should use? What would be the more appropriate way for us to understand how different populations end up with different health profiles? And when we use these terms, what are the implications for how we do research and outreach?

Kate ClancyAbout the Author: Dr. Kate Clancy is an Assistant Professor of Anthropology at the University of Illinois. She studies the evolutionary medicine of women’s reproductive physiology, and blogs about her field, the evolution of human behavior and issues for women in science. Find her comment policy here. Follow on Twitter @KateClancy.

The views expressed are those of the author and are not necessarily those of Scientific American.





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  1. 1. Anne Jefferson 5:11 pm 07/19/2011

    It seems like you (and colleagues) are trying to put a uni-dimensional term on a multi-dimensional problem. Food, activity level, and access to health care are all determinants of health outcomes, right? So, why try to use only one of them to label/divide/categorize people? Wouldn’t it be better to describe someone like me as food-rich/sedentary/health-rich, while describing my grad students (doing vigorous field work with crappy student health insurance) as food rich/active/health-moderate? I know more bins make problems for data analysis, but from my outsider point of view it seems like the way to go.

    Of course, I may be biased because I’m currently sorting volcanoes into a 3-dimensional conceptual graph.

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  2. 2. vnsharma 11:02 pm 07/19/2011

    The population can be categorized in hundreds and thousands of ways. May be qualitative differences between each human with the other. But I agree, for the time being with Trevathan’s with health -rich and health-poor because with passage of time the world population is getting divided into rich and the poor. In fact the global vocabulary is rich nation, poor nation. The industrial development and wealth creation has certainly changed the ways of life in a major way and taken humans from Natural to Un-natural conditions of existence. Each part of the Human Body has been designed for an optimal amount of work on minute to minute to year to year basis. So whatever wealth one puts in, the body parts have to function in accordance with the Rules of Nature and no amount of enhancements in Health care facilities can substitute that. For simple understanding the Example can be that if Humans do not use their leg for walking or running as much as designed by Nature for an optimal use the legs may not exist after a few hundred years if Darwin’s hypothesis is taken as correct. Same for other internal and external parts of the Human Body.

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  3. 3. kclancy 11:57 am 07/21/2011

    Anne, I think you make a great point, and I think we’re past the point of being able to divide everyone into nice bins of forager/agriculturalist/urban-dweller, industrial/traditional, health-poor/rich etc, and assume that those categories are not themselves heterogeneous. The question is how to make it sound pretty and have these more multidimensional interpretations of populations adopted by many. I do hope I wasn’t overstating the issue — I think everyone knows populations aren’t homogenous and that what we have isn’t perfect. I just haven’t yet seen anyone figure out how to move from these categories to something that captures variation but doesn’t go so crazy with terms or bins that we get too complex.

    vnsharma, thanks for writing. I still think it’s an oversimplifcation to say the world is dividing into rich and poor. And how do we define the diseases that occur more often in supposedly health-rich populations, like cardiovascular disease and cancer? And how do we define health-poor populations that rarely suffer from these diseases? I also think you may be confusing Darwin’s evolutionary theory — which deals with selection pressures — with a more Lamarckian view of change over time depending on use. Even with the rise of our understanding of epigenetics, what you are describing (for example, your example of leg use in humans) is unlikely. At the same time, I imagine we are largely in agreement about the questions posed in my post!

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