Wednesday, December 3, 2008

Does Curvy = Traditional When it Comes to Women?

When I'm not pregnant, I've got very much of an hourglass figure. My weight has fluctuated somewhat as an adult, but I seem to gain & lose pretty evenly all over. I might be a 38D-25-38 size 8 or a 34C-22-34 size 4 or something in between but my waist-hip ratio (WHR) stays fairly constant (in the 0.64-0.66 range). If a pair of pants or a skirt fits me in the hips, it almost certainly is going to need to be taken in at the waist.

So I found it very interesting to read about a new study in the December issue of the journal Current Anthropology done by Dr. Elizabeth Cashdan of the University of Utah. Previous work has established that a WHR of 0.7 or lower in women is associated with higher fertility and lower rates of chronic disease. Studies have also shown that men prefer a WHR of 0.7 or lower when looking for a mate, which makes sense from an evolutionary psychology standpoint. Dr. Cashdan noted, however, that the average WHR for women in 37 societies around the world she examined was >0.8.
"If 0.7 is the magic number both in terms of health and male mate choice, why are most women significantly higher? That's where the hormones come in.

Androgens, a class of hormones that includes testosterone, increase waist-to-hip ratios in women by increasing visceral fat, which is carried around the waist. But on the upside, increased androgen levels are also associated with increased strength, stamina, and competitiveness. Cortisol, a hormone that helps the body deal with stressful situations, also increases fat carried around the waist.

'The hormonal profile associated with high WHR (waist-to-hip ratio) … may favor success in resource competition, particularly under stressful circumstances,' writes Cashdan. 'The androgenic effects - stamina, initiative, risk-proneness, assertiveness, dominance - should be particularly useful where a woman must depend on her own resources to support herself and her family.'"

In societies where women tend to be less economically independent, the typical female WHR is lower than in societies where women bear more responsibility for providing for themselves and their families.

The question Dr. Cashman's research raises in my own mind is this: given that I'm both curvy and prefer a more traditional gender role, which is the direction of the causality? Am I curvy because I'm more traditional or am I more traditional because I'm curvy?


Elisheva Hannah Levin said...

Good question.

Most likely, you're more traditional because you're curvy. That is the hormone balance that explains the curviness is pretty straight forwardly the result of genetic inheritance. But hormone balance does more than determine the amount and placement of body fat in all the right places; they also influence the brain and behavior.

Of course, nuture does influence hormone excretion, just as nature does, but in the case of female fertility, the hormonal balance must be reasonably stable in order for the human race to continue in good times as well as bad times.
However, epigenetics (the influence of the environment on gene expression) could explain the anthropologist's hypothesis. However, it sounds speculative. I am going to have to look up the paper and see what genetic data she has.

Kristina said...

This is extremely interesting. I, too, will have to take a closer look. I think hormones play a huge roll in many genetic functions. Of course, I am not a scientist...