Sexual attractiveness as a function of age

Sexual attractiveness varies as a function of age for both men and women. However, the curves must look very different for males and females. Let’s define sexual attractiveness as the percentage of people of the opposite sex that would enjoy having sex with a person. I haven’t checked the literature on this, but I suspect the curves (averaged across individuals) may look something like this…

Note the sudden rise for the female during her teens and the delayed rise for the male. Note also the sudden drop for the female during her thirties and the much later drop for the male. Further note that I’ve drawn the peak lower and wider for the male. This is consistent with the idea that a girl at 20 is desired by a larger proportion of the opposite sex than a guy at his peak.

If we were to define sexual attractiveness as the frequency of consensual heterosexual sex acts, then the integral (i.e. the total count of consensual heterosexual sex acts) would by definition be equal for both sexes – consistent with the curves as shown, where the female’s peak is higher but also narrower, yielding a similar integral over the lifespan.

The sudden rise and fall of the female’s attractiveness may pose challenges to her character and development that the male does not face.

If we were to zoom in on a particular individual’s attractiveness across a few days spanning a range of emotional states and changes of status, I think we’d see a nearly constant curve for the female. A hot girl can be happy and perky or crying in a corner of the room – she is still hot. This constancy of sexual power confers the immense emotional freedom that women enjoy: emotional instability is less of a liability if it does not compromise sexual power.

Not so for a guy. If he breaks down emotionally, he loses all masculine appeal. His sexual power similarly declines when he fails professionally and loses status.

A woman’s attrativeness, though it fades with age, is stable like the price of gold locally in time. A man’s attractiveness is fickle by comparison – more like the market value of modern art or popmusic: largely a social construction arising in an unpredictable process of recurrent message passing.

Does this have implications for mating and long-term partnerships?

Let’s go with the conventional notion that a stable match is one in which both partners are similarly attractive – and neither is too tempted by more attractive alternative options.

But a stable match at one point in time is not necessarily a stable match at a different point, if attractiveness varies differentially for the sexes.

For an age-matched couple, the woman will be more attractive in younger years and the man more attractive in later years, leading to instability over essentially the entire course of the relationship (with a short moment of balance in the middle). If they meet young and she has more alternative options than he does, but sticks with him regardless, she could be thought of as investing in his potential. When the tables turn, he may repay her loyality. Alternatively, he may defect and leave her for someone younger and more attractive. So an age-matched early commitment is risky for the woman in the long term.

This assumes that the particular two people have an equal lifespan integral of sexual attractiveness. If a young age-matched couple is matched in attractiveness as well when they meet, then her risk of losing him is even greater.

If she waits until her 30s to find an age-matched partner for the long term, her chances of getting someone of equal lifespan attractiveness are slim, as her best years are past. For the long term, she is a definite bad deal for an age-matched male partner who is currently or over the lifespan equally attractive. However, he may be interested in the short term, while the match is stable.

If the male is 10-20 years older, then the attractiveness curves are in better alignment and the match is more stable over the long term. This is a common scenario and advantageous to both sides.

Conversely, consider the case where the female is 10-20 years older. His attractiveness at 22 may be a match for hers at 37 – for a short, sweet moment.