Sexy Science

It seems that the closer to symmetrical a man’s facial features are, the more likely it is that a woman will choose him as a partner. However, there also appear to be other unexpected benefits

WHEN checking out the opposite sex, what makes one face more attractive than another? Lots of things come into play, including apparent healthiness, age, masculinity or femininity, and even the resemblance of the face to your opposite sex parent, but one quality that has consistently been shown to make a person’s face appealing to the opposite sex is a high degree of symmetry.

And it would seem that this is no socially constructed preference that we learn from looking at perfect airbrushed models in magazines. According to a paper given by psychologist Tony Little of Stirling University at a recent international conference in Edinburgh, these preferences are observed across cultures and are rooted deep in our evolutionary past.

So, what’s the big deal with a symmetrical face? Little and his colleagues carried out experiments where they asked men and women to rate the attractiveness of images of faces that had been computer manipulated to vary the degree of symmetry.

Both men and women preferred the more symmetrical images, and Little suggests that this is because symmetry is an indicator of good genes and a good immune system that have allowed the body to withstand the rigours of development.

If you go for a symmetrical partner, then any children that you have together are likely to inherit these good qualities.

It makes sense, then, that the researchers found that women showed a much greater preference for symmetry in men’s faces when in the most fertile phase of their cycle. In general it may be better for women to go for less symmetrical men because the good-looking guys might be less inclined to commit to their partner and invest in children since they tend to have other opportunities. However, although of course women make any conscious partner choices they like, it seems biology could be propelling women towards hooking up with symmetrical men when it comes to getting genetic benefits for their kids.

In support of this idea, Randy Thornhill and Steven Gangestad of the University of New Mexico, found that more symmetrical men (according to measurements of foot, ankle, hand, wrist, elbow and ear dimensions) had more lifetime partners and they were more likely to be chosen by women for extramarital liaisons. Another study found that T-shirts worn by more symmetrical men were rated as smelling better than those worn by less symmetrical men, but only by women who were in their fertile phase. Finally, and perhaps most astonishingly, Thornhill found that women experienced more orgasms if their partner was more symmetrical. Not only that, but the degree of symmetry was linked to the rate of high sperm-retention orgasms when coming together, as it were, which, it has been suggested, increase the chances of pregnancy.

All this points to the fact that our preferences for symmetry have a biological basis and it seems that this predilection goes back a long way into our evolutionary past – even monkeys, our distant relations, are partial to a bit of facial symmetry.

Little, along with his colleague Corri Waitt, checked out the reactions of captive male and female rhesus macaques to pictures of macaque faces that had again been manipulated to vary in bilateral symmetry. They found that males preferred feminine symmetrical faces and that females preferred masculine symmetrical faces, as measured by the length of time and number of times the monkeys looked at such images versus less symmetrical or masculine/feminine images. Female macaques then don’t seem to vary in their preferences in the way that women do depending on whether or not they’re fertile.

Why not? Well, it most likely comes down to what female monkeys can get from their guys. I can guarantee you won’t see a male macaque feeding the baby or pushing the Hoover round, so basically the females are likely to choose mates only on the basis of their genetic qualities that show up in a masculine, symmetrical appearance and should enhance the health of their babies. Then again, maybe they’re just after good sex.

• Help Tony Little with his research at www.alittlelab.com