Female Attractiveness Over Time

UPDATE Jan. 2013: If I had to redo the graph today, I would extend the peak of psychological qualities through to at least 30. This would probably produce a combined peak around age 24-27. It's hard to define "attractiveness" though. If you're in a bar or night club, men will judge based on mostly appearance alone. In a situation where you get to know people over a longer period of time, the woman's psychological characteristics will play a greater role in defining her attractiveness. So the 50:50 ratio in the weighting of these two traits is a kind of compromise. 

In comparison to male sexual attractiveness, female attractiveness over time is easier to model and exhibits less variation. This is probably because the biological constraints on reproduction for women are greater than for men in light of their far greater energy investment in offspring. Again, this model is an oversimplification, but I think female attractiveness over time can be effectively modeled based on 2 rather than 3 (for males) factors:

1. Physical qualities: sexual maturity and fertility, physical maturity, health and fitness level, probability of surviving childbirth and critical years of childrearing
2. Psychological qualities: confidence, flirtatiousness, independence, ability to manage complex family relationships and responsibilities

Part of the second set of qualities could be separated into a third category, but this would reduce the comparative weight of physical qualities, which are important enough to deserve half the weight of the overall attractiveness index.

In contrast to men, a woman's physical attractiveness goes through ups and downs as she becomes pregnant, gives birth, recovers, and is once more physiologically ready to give birth. Likewise, her psychological attractiveness goes through swings as she becomes correspondingly more or less flirtatious. One can imagine such "wiggles" on the graphs below instead of smooth curves.

A woman's graph of attractiveness over her lifetime depends in part upon decisions such as when and how many children to have. A woman who has many children successively may in effect "squander" her attractiveness more quickly than one who has just one or two, because of the greater physical toll of having multiple children close together. Also, a woman who begins having children later can enjoy more years of peak attractiveness than one who starts early. However, by having children when the body is most equipped to have them, the woman who starts early might do better at preserving her health in the long run.

In terms of difficulty of childbirth, risk of death during childbirth, and the physiological toll of having offspring, I believe Homo Sapiens takes first or near first place among the Animal Kingdom, with our unusually large-headed offspring, long gestation, and lengthy period of breastfeeding. This heightens the importance of physiological fitness and in effects skews the attractiveness curve of a woman towards her early childbearing years when she has the most strength and has not yet put her body through the ordeal of childbearing. In other species the age of the female may be less important as long as she is fertile.

One might suppose that a woman would become entirely sexually unattractive upon reaching menopause, since she can no longer reproduce. However, at least in modern societies, this is clearly not the case. As reproduction becomes a more and more of a secondary "goal" of intimacy (thanks to medical advances, contraception, and a host of related phenomena), post-menopause women become comparatively more and more attractive than they were before. Also, as populations age, there are fewer and fewer young women to focus sexual energy on, and older women and their sexuality have become increasingly "normal."

There are many individual variations in the graph below depending on individual factors such as how quickly and completely a woman's body recovers from childbirth, however, the graph below seems to be fairly accurate for women in modern societies in general.

It is rare for a woman's peak overall attractiveness to extend beyond age 30. This might occur if she has a very youthful appearance and matured late as an individual, with complexes or lack of experience at age 20-25 finally giving way to spontaneity and flirtatiousness by age 30. In primitive societies peak attractiveness might come as early as age 18. Not too long ago this was the average age of first pregnancies in many traditional societies.

Once again, as in the previous post, we find that sexually attractive psychological qualities are expressed in approximately the degree to which a woman senses she is attractive to the opposite sex. Are these qualities a cause or an effect? Probably a bit of both. With physical attractiveness comes confidence, but with age may also come greater freedom to be oneself, greater spontaneity, etc. These qualities may enable a woman to remain attractive to potential mates well into middle and even old age, even though her peak attractiveness was still somewhere back around age 25.