Monday 26 October 2015

Sexual selection has been done mostly by the bride's parents - i.e. middle aged couples - hence it is much more economically-rational, and culturally sensitive, than is generally supposed

Mate choice, throughout human evolutionary history, has been mostly done by parents, that is by middle aged people - and especially the woman's parents:

Therefore, there has not been much in the way of natural selection for women to be good at choosing their sexual partners or husbands - and it should not be surprising if modern women are in fact not good at this.

(Which, clearly, they aren't.)

This means that it is not a valid test of sexual selection in humans to ask young women to rate men for attractiveness - from an evolutionary perspective this is all but irrelevant.

If modern young women happen to prefer to choose 'hot' young men as sexual partners or husbands (charming men, dominant men, men with strong jaws and big shoulders and narrow hips in a V-shape, 'guns' or 'six pack' etc...) this kind of preference is highly likely to be a contingent and ephemeral cultural artefact - resulting from women's instinctive susceptibility to peer pressure, as amplified and distorted by the modern mass media.

The fact is that modern young women - instinctively speaking, in terms of evolved adaptations - haven't a clue about how to choose a good sexual or marriage partner! Indeed - why should they? since such preferences had little or no impact on human evolutionary history.

(Sex outside of marriage may lead to children being born, but in the past - in a context of average child mortality rates of more than a half - these children lacking the support and resources of a long-term marriage type relationship would almost certainly have died before maturity, and/ or been unhealthy and low in status.)

To test for what traits have been sexually selected, a far better test would be to ask middle aged parents to choose what kind of men they would want as a husband for their daughter - because that decision is the one that was under strong selective pressure over many generations.

I think it would be found that parents chose - on average - rationally, on the basis of whatever (unglamorous!) traits best indicated a faithful, steady and good provider for their grandchildren.

In other words, sexual selection as it actually was would quite often (in many types of economy - although not all situations) favour 'Dads' not 'Cads' - and if their daughters found the Dad type of man was not much of a turn-on... well so what! There are more important things when life is harsh and very few children survive to maturity.

Under most ancestral conditions, the sexual preferences of young women would not make any difference - one way or the other.

Reference: Apostolou, M. (2012). Sexual selection under parental choice: Evidence from sixteen historical societies. Evolutionary Psychology, 10, 504-518. This paper makes clear why, in traditional societies, Dads need not fear spousal infidelity with Cads. Apostolou looked at the level of punishment when a woman is discovered to have committed adultery. Three levels were coded: No punishment/ light punishment; moderate (!) punishments including beating and divorce; severe punishment such as beating to death. No punishment/  light punishment were found in 5 out of 54 of agropastoral societies; while severe punishments for adultery were found in about two-thirds of these societies - a large majority of 35 out of 54.