For a healthy relationship, men should be ugly and rich, women pretty and mixed-race

Have you ever seen a happy couple walking down the street, holding hands, laughing and being generally smoochy, and thought to yourself, "How did that guy get her?"

I’m that guy.

As a fully paid-up member of the "batting out of my league club," it comes as no surprise to me that the happiest hetero relationships are those in which the female is objectively more attractive than the male.

McNulty, Neff and Karney in their report Beyond initial attraction: Physical attractiveness in newlywed marriage, published in the Journal of Family Psychology, found that the relative difference between partners’ levels of attractiveness is one of the most important factors when predicting marital behaviour. In relationships in which the wives were more attractive than their husbands, both the husband and wife were happier than in situations where the husband was more attractive than the wife. Indeed, a strong conclusion of this study was that relatively more attractive husbands were less satisfied. As opposed to new relationships, where being similarly attractive helps form a strong bond, similarity in attractiveness was unrelated to a married couple’s satisfaction and behaviour.

This got me thinking, what does it mean to be attractive? How can you measure this?

Michael B Lewis from the School of Psychology, Cardiff University has an interesting take on this. He recently published Why are mixed-race people perceived as more attractive? on perceptionweb, and also presented Who has the ‘X Factor’? at the 2010 British Psychological Society’s Annual Conference.

To test his theory that people from a mixed-race background appear proportionally over-represented in TV talent competitions such The X Factor, 1205 images from Facebook were shown to 20 white psychology students (is this a large and diverse enough group?), who rated each face on its attractiveness on a 9-point scale (5 being average). The racial background of those in the photos was inferred from the Facebook group from which the photos were taken. The result was that there was a small but highly significant difference in the attractiveness of mixed-race faces compared to white and black faces.

This is an interesting result and could point towards a perceptual demonstration of heterosis in humans. Heterosis is the idea that breeding with people genetically different to you leads to offspring genetically fitter than you. The theory is that the child would possess the genetic strengths of each parent and less of their weaknesses. Two genetically similar parents (that is, both black or both white) may have similar strengths and weaknesses, so the weaknesses may not be bred out.

But does facial attractiveness really correlate to genetic fitness?

There have been numerous studies on this topic, and the answer would seem to be yes. In terms of evolution, it makes sense that those you are attracted to are also those with whom you would have genetically strong children.

Or in the paraphrased words of Thornhill and Gangestad, “Humans discriminate between potential mates on the basis of attractiveness and it is reasonable to hypothesise that the psychological mechanisms underlying attractiveness judgments are adaptations that have evolved in the service of choosing a mate so as to increase gene propagation throughout evolutionary history.”

For a summary of how facial attractiveness can represent the health of a subject and their overall genetic well-being, see Thornhill and Gangestad’s Facial attractiveness in Trends in Cognitive Sciences, from where the above quote comes. There is also a nice discussion of how preferences change during menstrual cycles.

My conclusion therefore is that if you’re a hetero guy, you should find a girl better looking than you are, and to widen the attractiveness gap even further, it would help if she was mixed-race. Don't push it too far though, as there is bound to be some limit on how much more attractive a girl can be. Remember, similar looks at the start can help get the relationship going, it is after this point when an attractiveness gap can help.

This seems quite easy for men so far, as all the criteria have been placed upon the women. Not so.

In the seminal report Partner wealth predicts self-reported orgasm frequency in a sample of Chinese women, published in Evolution and Human Behaviour, Thomas V. Pollet and Daniel Nettle investigated the relationship between women’s self-reported orgasm frequency and the characteristics of their partners. They found that women report more frequent orgasms the higher their partner’s income. They controlled for age, health, happiness, educational attainment, relationship duration, wealth difference between the partners, difference between the partners in educational attainment, and regional location. They consider that wealth is seen as desirable in potential partners by women all over the world and studies in diverse populations have found that increasing wealth increases male marriage success. Thus, all other things being equal, richer men are preferred to poorer ones as mates.

The purpose of this study was to understand the evolution of the female orgasm – what is its adaptive significance? They come to a number of conclusions:

• The results could be an artefact of reporting bias. Reporting bias can act in two ways, either by women with frequent orgasms overestimating their partner’s income or by women with high-quality mates over reporting their orgasm frequency.
• There may be assortative mating of desirable men with women susceptible to being highly orgasmic. There is a heritable component to female orgasmic function (go on, ask your Mum…), but it is not known whether these particular genetic features are also involved in attraction and mate choice.
• More desirable mates may cause women to experience more orgasms. This is the interpretation most consistent with the functional view of the female orgasm – that is, as the orgasm feels good and comes about more often with desirable males, then this helps females find good men.

I love the fact they cite Alcock (1987) and Thornhill, Gangestad & Comer (1995)...

In conclusion therefore, men should be rich and ugly, women should be attractive and mixed race. QED.

Two asides:

• This conclusion is exceptionally shallow (I don't believe it myself). There are layers and layers of human psychology and culture that go on top of this. Plus the Lewis study used 20 white psychology students - surely we need a bigger base than this. Feel free to pick this apart, I was just having fun with it.
• I suspect that humans are evolutionarily wired to find women better looking than men. It was seen in the Lewis study that the female photos had a higher average score than the male photos for each race studied. Could this make sense with regards to sexual selection? I’m sure there are studies out there looking into this idea. I’d like to hear you thoughts on this, and the above topics.