Why is physical attractiveness more important for women?

In many animals, including most mammalian species (roughly, milk-producing animals), the male looks much more spectacular than the female and is more dependent on his looks for reproductive success.  A classic example is that of peacocks and peahens, where the male looks magnificent and the female comparatively dull; another example is of lions vs. lionesses.  A general theme in such species is that the investment of the female in producing and rearing offspring is much greater, making the females largely choose the males and the males court the females, for which they need to impress the females, which they often do through their looks.  Among humans, women invest more heavily in raising children, and courtship, with a minority of exceptions, mostly comprises of males seeking to impress women, but the general theme in human societies is that physical attractiveness (henceforth attractiveness) is more important for women.  Why is this so?

The feminist explanation is straightforward: patriarchy attempts to preoccupy women with their looks in order to keep them down.  However, concern about looks and bodyweight have been documented in a sample of young adult Iranian women born after the Islamic revolution (late 1970s) and having grown up with hardly any exposure to Western culture.⁽¹⁾  So a better explanation is needed.

Charles Darwin argued that among humans, mate choice on the part of men became more important, and the males selected for beauty in women, making women more attractive than men in an absolute sense.  I personally find attractive women more impressive looking than attractive men, and a couple of years ago would have found Darwin’s hypothesis appealing, but the problem is that some heterosexual women may find attractive men more impressive than attractive women.  So how does one make the definitive argument that in humans the females have ended up looking better than the males?

Jonathan Gottschall^{(2, pdf)} has come up with a revised solution to the problem by adding to a previous explanation by Symons, who argued that in humans “a female’s reproductive value can be assessed more accurately from her physical appearance than a male’s reproductive value can,” leading to a greater emphasis on attractiveness in women.

Gottschall addresses the role of parental investment.  Human babies take a long time to mature and are totally dependent on parental care for survival during the first couple of years.  So successful child rearing requires extensive parental investment on the part of men also.  Hence, in choosing a man for reproductive purposes, women will emphasize how likely a man is to stay around and help raise the child.  This will translate to reduced emphasis on how attractive a man is.  This is a reasonable argument and undoubtedly partially accounts for the lesser emphasis on attractiveness in men.

Gottschall elaborates on Symon’s notion for why there is greater emphasis on attractiveness in women.  At any given time there is large variation among women regarding how fertile they are, and the fertility of women can be assessed to a good extent from their looks, better so than the case with men.  These facts altogether make men somewhat choosier, i.e., place a stronger emphasis on women’s looks.  Gottschall describes humans as a partially sex-role reversed species by virtue of the men being more involved in raising children and the men being choosier with respect to mate selection.  There are some shortcomings with this notion.

Whereas it is true that at any given time there is great variation among women with respect to fertility, age accounts for a lot of this variation, much more so than in men (e.g., many 60-year-old men can father a healthy child, but hardly any woman this old could give birth to a healthy child).  So it should be clear that young adulthood will be more important for women’s attractiveness than men’s attractiveness.  But what about body shape variables after removing the age factor? 

Men strongly prefer above average femininity in women’s faces and physiques, and physical femininity is related to fertility and fecundity.^{(face shape; physique)}  Yet, the great majority of men will not refuse an opportunity for sex with women who are nowhere close to what they find optimally appealing.  So why is a need for beauty causing anguish for a lot of women when most women do not have to be anywhere close to this ideal to attract men?  And, as long as the woman is a young adult, how does it hurt men to impregnate as many women as they can get a hold of as long as they are not choosing less attractive women over more attractive ones?  Gottschall’s explanation is inadequate.       

When men have lots of women to choose from, they will pick the best looking ones, but very few men are normally in this position.  There was a time when humans who moved into the northern hemisphere encountered a very harsh environment and suffered an excess of male deaths because they were more dependent on hunting for survival.  So at any given time there was an excess of women and most men were not in a position to support multiple wives.  This would be a prime scenario where a woman’s attractiveness would especially matter.  This scenario is the most plausible reason behind the rapid rise of hair and eye color diversity in Northern Europe as well as the more feminine waist-hip proportions of Northern European women,^{(3, pdf)} their finer facial features, etc.  But, a comparably stronger emphasis on women’s attractiveness is typical of non-European societies also.  So Gottschall’s hypothesis needs to be modified.

There are two additional factors that are reducing the emphasis on men’s attractiveness and increasing the emphasis on women’s attractiveness.

The general pattern of men courting women by impressing them holds true for humans but men have become less dependent on looks because of the way human intelligence has developed.  Many men attract women through their musical instrument-playing ability, writing ability, sense of humor, artistic skills and other abilities uniquely associated with human intelligence.  Just as many male animals look more impressive than their female counterparts and use their looks to attract females, the highest expression of many courtship-relevant uniquely human abilities such as artistic skills and musical ability are typically found in men, and men gifted in these abilities use them to impress women.  So the way human intelligence has developed makes physical attractiveness less important for men.

The other factor is competition between females for males,^{(4, pdf)} seen in light of the development of human intelligence.  If most women share a similar notion of an ideal man, and there are few such men, these men will have their choice of women and will naturally select the best looking ones.  Because of the way human consciousness has developed and mirrors, most women know how they look in comparison to others, and if they are not very attractive, then this will be a source of anguish for many because they are at a disadvantage when it comes to competing with other women for desirable men.  So the source of anguish for women, notwithstanding the willingness of most men to have sex with women nowhere close to what they find optimally attractive, is inter-female mate competition given women’s high standards for men, whereby they will typically reject many if not most interested men and lament that just about all other women are after the men they want.

So here is a summary of why attractiveness has become more important for women in humans, at odds with the common pattern in mammals:

• Greater paternal investment in children on the part of men – corresponds to reduced emphasis on male attractiveness on the part of women.
• Narrower age range of optimal fertility in women – corresponds to increased emphasis on youth for women.
• Human intelligence development, giving men cognitive abilities to impress women – corresponds to reduced need for male attractiveness.
• Inter-female mate competition in light of human consciousness development and the development of mirrors – a source of anguish pertaining to looks, originating from within women.

There may be additional factors that I am unaware of, but patriarchy is an unlikely factor.

References               

1. Abdollahi, P., and Mann, T., Eating disorder symptoms and body image concerns in Iran: comparisons between Iranian women in Iran and in America, Int J Eat Disord, 30, 259 (2001).
2. Gottschall, J., Greater emphasis on female attractiveness in Homo sapiens: A revised solution to an old evolutionary riddle, Evolutionary Psychology, 5, 347 (2007).
3. Frost, P., European hair and eye color: A case of frequency dependent selection?, Evol Hum Behav, 27, 85 (2006).
4. Campbell, A., Female competition: causes, constraints, content, and contexts, J Sex Res, 41, 16 (2004).