There is no argument about the fact that women spend a lot more time, effort, and money on their appearance than men do. Clearly, they do so because how they look is more important to them.
That begs the question of why appearance is so much more important to women than men.1 One view is that women's greater interest in appearance is socially learned — that it derives purely from social promotion and marketing of a feminine image.
Just as people acquire a taste for drinking coffee, so they acquire a belief that appearance is more important to women than men.
The alternative evolutionary explanation harks back to an evolutionary past where women competed over the most desirable men based on their own physical attractiveness.
The greater importance of physical appearance for women's mate value is confirmed by the fact that their bodies have been more extensively remodeled by sexual selection than is true of men.2,3 Sexually selected feminine traits include narrow waists, permanently enlarged breasts, shorter faces, smaller hands and feet, and conspicuous subcutaneous fat stores. Men are sexually selected for height, muscularity, and beardedness.
A Thought Experiment
If the social learning theory were correct, it would mean that children adopted into a society where physical appearance is unimportant would not care about how anyone looked and would not see female appearance as more important than male appearance. There is no such society. The next best thing is a society where men take more care of their appearance than women do. There is only one good example of this — the Wodaabe of the Sahel that is often mistakenly cited as closing the case for the social learning explanation.
The problem is that these cattle herders have a very unusual marriage system where fathers invest little in children during their early years.4 Wodaabe women pay an unusual amount of attention to masculine physical attractiveness as a way of increasing the chances that their offspring are healthy.
So there is a good evolutionary explanation that is peculiar to this society but that clearly includes social learning. Social learning is thus part of the evolutionary process and not a rival explanation after all.
Not all evolutionary explanations have to be gene-based, or biological. Even so, if a long history of gene selection contributed to our perceptions of physical attractiveness, there ought to be some evidence of this from brain biology and sex differences in brain development.
Insights from Gender Development and Androgen Insensitivity
Androgen insensitive genetic males are of interest here. Because their bodies do not react to testosterone, they grow up with a female body in external appearance.5 They are also attracted to men and evince a feminine psychology and behavior, including taking more interest in their appearance than most men.
The issue here is that much of what manifests as typical masculine psychology and behavior is contingent on masculinization of the brain before birth that does not occur in androgen insensitive individuals. Such developmental mechanisms are subject to natural selection.
The counterpart to this phenomenon involves genetic females whose brains are masculinized before birth. This can happen if mothers happen to produce more testosterone than usual from their adrenal glands. Another reason for masculinized female brains was the drug diethylstilbestrol (DES) that used to be used as a contraceptive.2 When women accidentally continued to use the drug during pregnancy, their daughters' brains were masculinized.
As a result, there was greater interest in stereotypically masculine toys and activities, and a higher probability of growing up to be homosexual. In some cases, this may involve diminished interest in personal appearance.
Critics of the biological perspective would argue that women are forced to present themselves as desirable objects because they lack social power. If that were true, one would predict that with increasing gender equality in employment and political leadership that women would take less care over their appearance.
Insights from Gender Equality
Yet, the opposite would appear to be true. Female spending on clothes averages $400 each year at the age of 20 and rises steadily up to the early forties when it peaks at over $700 before declining in old age. So, as women increase in earning power and social status, their interest in physical appearance does not decline, and may actually increase, if the amount spent is any guide.
For purposes of comparison, single men spend around $400 on clothes annually whereas married men average just $280. So while men may dress to impress potential mates, married men who solved the problem of attracting a mate, make do with the bare utilitarian minimum in their clothing budget
Attracting mates is not everything, of course, and a woman who takes care over her dress and appearance before work is probably more interested in seeming professional and competent than sexy.
That is yet another example of women's appearance being held to a high standard. There is nothing new about that. It is as old as our species.
1 Jackson, L. (1992). Physical appearance and gender: Sociobiological and sociocultural perspectives. Albany: State University of New York Press.
2 Barber, N. (2002). The science of romance. Buffalo, NY: Prometheus.
3 Barber, N. (1995). The evolutionary psychology of physical attractiveness. Ethology and Sociobiology, 16, 395-424.
4 Bovin, M. (2001). Nomads who cultivate beauty: Wodaabe dances and visual arts in Niger. Uppsala, Sweden: Nordic Africa Institute.
5 Galani, A. Kitsiou-Tzeli, S., Sofokleus, C., Kanavakis, E., and Kalpini-Mavrou, A. (2008). Androgen insensitivity syndrome: Clinical features and molecular defects. Hormones, 7, 217-229.