Sociobiology and Anorexia

As an aspirant anthropologist of a biocultural bent, I often analyze behaviors from an evolutionary framework; so when we started ANT 670 with an introduction to the concepts of cultural primatology and ethnoprimatology, it was right up my alley. One of my interests is the relationship between biological realities and social capital. Smuts (1987) wrote about baboons’ evolutionary fitness in relation to their social network; Blaffer Hrdy (1988) wrote about the potential adaptability of skewed sex-ratios among mammals; and Small (1989) wrote about a female Barbary macaque’s dramatic rise in power in her troupe through the formation of alliances. The three articles suggest that, among social animals, one’s social rank is tied to one’s biological fitness, and vice versa.

I have many interests in anthropology that are not entirely disparate, yet their interrelatedness is not obvious: autism, sexuality, and body image are my broad topics of interest.  However, for this post, I will just stick to body image.

Estimates place the rates of Anorexia nervosa at about 1 in 100 women and 1 in 1,000 men (Delinsky and St. Germain 2012). I take the perspective of Nesse and Williams (1996), that many diseases, or in some cases our vulnerability toward them, are the result of a trait that was at one point (or possibly still is) adaptive in some cases. Sickle Cell is an obvious example—the heterozygote is protected against malaria (and may have some issues with cell-sickling at altitude), while the sickle-cell homozygote is bound to lead a short, pained existence without proper treatment. Other examples include anemia as a strategy to defend against bacterial infection (bacteria feed on iron), and fever as a tool, rather than the result, of the immune system.

In the case of Anorexia nervosa, evolutionary psychologists have hypothesized about the possible utility of Anorexia-like behaviors in early humans that didn’t carry over into our modern world, a sort of biotemporal mismatch. Some consider anorexia to be an indirect consequence of an adaptation for reproductive suppression that is triggered in developing societies by a desire to be thin (Wasser and Barash 1983, Surbey 1987, Voland and Voland 1989). Others have seen it as sexual selection through intrasexual competition gone haywire (Abed 1998, Mealey 2000, Lozano 2008). Still others view it as adaptive in that some of the behaviors associated with Anorexia nervosa would be adaptive in settings of famine (Guisinger 2003). Noting that none of the hypotheses are successful in considering the entirety of Anorexia from an evolutionary perspective, I do find that a combination of the evolutionary mismatch Guisinger (2003) suggests mixed with a less ethnocentric interpretation of Abed (1998) to be compelling.

In keeping with this biocultural, Darwinian medicine perspective, it is important to recognize that one can be said to have a Bordeauean “body capital,” meaning that the way one’s body presents sends messages to the people around who then make judgments about your health, socioeconomic status, mate value, etc., based on a cursory look at your physique. In the U.S., in which a thin body is idealized among women, thinness is associated both with beauty and with social status. It can be inferred that someone who has the body shape near what we are taught to see as “ideal” (thin, fit, etc.) is that way because they have a.) good genes, b.) the socioeconomic resources to eat well and exercise. In many developing countries that are bombarded with U.S. media, thin bodies are, if not attractive in their own right (some may see a more robust body as attractive), seen as a tool to access power and prestige (Kanaaneh 2002, Becker 2004). Similar behaviors are also seen among, for example, Asian women who receive double eyelid surgery: a form of Foucauldian discipline that allows them to take a more active role within “white” hegemony (Kaw 1993).

The aforementioned primate studies demonstrated the role of social networks in evolutionary fitness. It shows how important one’s social relations are to health, and how this is not just a cross-cultural thing but a cross-species one as well. I’ve extended the overarching concept to the case of Anorexia nervosa, in which one’s biological body cannot be divorced from the social role it fulfills, creating a feedback loop of ill health. In all cases, power equals mate value equals survival of one’s genes, making behaviors that would increase this power (by achieving thinness) seemingly evolutionarily strategic. The evolutionary necessity of forming social networks as a strategy for success is a double-edged sword.

References

Abed, R. T. (1998). “The sexual competition hypothesis for eating disorders.” British Journal of Medical Psychology 71(4): 525-547.

Becker, A. E. (2004). “Television, disordered eating, and young women in Fiji: Negotiating body image and identity during rapid social change.” Culture, Medicine and Psychiatry 28(4): 533-559.

Blaffer Hrdy, S. (1988). Daughters or Sons. The Primate Anthology: Essays on Primate Behavior, Ecology, and Conservation from Natural History. R. L. Ciochon and R. A. Nisbett. Upper Saddle River, NJ, Prentice Hall: 44-55.

Delinsky, S. and S. St. Germain (2012). Anorexia nervosa. Encyclopedia of Body Image and Human Appearance. T. F. Cash. Waltham, MA, Academic Press. 1: 8-14.

Guisinger, S. (2003). “Adapted to flee famine: Adding an evolutionary perspective on anorexia nervosa.” Psychological Review 110(4): 745.

Kanaaneh, R. A. (2002). Birthing the nation: Strategies of Palestinian women in Israel, Univ of California Press.

Kaw, E. (1993). “Steven Polgar Prize Essay (1991). Medicalization of Racial Features: Asian American Women and Cosmetic Surgery.” Medical Anthropology Quarterly 7(1): 74-89.

Lozano, G. A. (2008). “Obesity and sexually selected anorexia nervosa.” Medical hypotheses 71(6): 933-940.

Mealey, L. (2000). “Anorexia: A “losing” strategy?” Human Nature 11(1): 105-116.

Nesse, R. M. and G. C. Williams (1996). Why we get sick: The new science of Darwinian medicine, Vintage.

Small, M. F. (1989). Ms. Monkey. The Primate Anthology: Essays on Primate Behavior, Ecology, and Conservation from Natural History. R. L. Ciochon and R. A. Nisbett. Upper Saddle River, NJ, Prentice Hall: 56-59.

Smuts, B. (1987). What Are Friends For? The Primate Anthology: Essays on Primate Behavior, Ecology, and Conservation from Natural History. R. L. Ciochon and R. A. Nisbett. Upper Saddle River, NJ, Prentice Hall: 36-43.

Surbey, M. K. (1987). “Anorexia nervosa, amenorrhea, and adaptation.” Ethology and Sociobiology 8: 47-61.

Voland, E. and R. Voland (1989). “Evolutionary biology and psychiatry: The case of anorexia nervosa.” Ethology and Sociobiology 10(4): 223-240.

Wasser, S. K. and D. P. Barash (1983). “Reproductive suppression among female mammals: implications for biomedicine and sexual selection theory.” Quarterly Review of Biology: 513-538.

One thought on “Sociobiology and Anorexia”

Comments are closed.