Asymmetry could account for a fifth of the variation in romantic jealousy from person to person, says a Canadian researcher. Just about everyone is lopsided to some extent. But in recent years, a series of animal and human studies have suggested that the implications of asymmetry go far beyond struggling to find shoes that fit both feet. It seems that people who are more symmetrical are not only healthier, more fertile and perhaps even smarter - they are also more attractive. This led William Brown at Dalhousie University in Halifax, Nova Scotia, to wonder about jealousy. "If jealousy is a strategy to retain your mate, then the individual more likely to be philandered on is more likely to be jealous," he speculated. And if people who are less symmetrical are less desirable, they are more likely to be cheated on. To test his theory, Brown looked at 50 men and women in various kinds of heterosexual relationships, comparing the sizes of paired features such as feet, ears and fingers. The volunteers then filled in a questionnaire already used in other studies to assess romantic jealousy. He found a strong link between asymmetry and romantic jealousy. Asymmetry could account for over a fifth of the variation in romantic jealousy from person to person, he says. To make sure less symmetrical people are not simply cursed with more jealous personalities, Brown also assessed their propensity to be jealous outside the relationship, in the workplace for example. But the less symmetrical people were no more likely to be jealous in general, he found, than more symmetrical folk.
A separate study by UK researchers has revealed that women with the most alluring voices have the most attractive faces. Sarah Collins and Caroline Missing, at the University of Nottingham, played recordings of 30 young women to men who later saw their photos. The men judged women with attractive voices as the best looking, reveals the study published in the latest Animal Behaviour.
Beauty really is in the eye of the beholder. Rather than always chasing the best-looking members of the opposite sex, some animals prefer mates that the majority find decidedly unattractive. Studies of how birds, fish and people choose mates have found that members of the same species tend to find the same things attractive. For instance, peahens prefer to mate with brightly colored, long-tailed peacocks, while women prefer tall men. Those attractive traits are supposed to signal beneficial characteristics such as an increased chance that any offspring will survive. Male lions with long, dark manes are more attractive to females and more intimidating to rivals, US research involving dummy animals shows. Manes vary from light blond to black and can be up to foot long. The research team planted pairs of life-sized toy lions with different types of mane near males and females in the Serengeti National Park in Tanzania, and monitored the lions reactions to the 'intruders'. In all cases, males preferred to approach dummies with lighter, less shaggy manes. But females did the opposite. They preferred to approach darker males, suggesting they are a better bet as a mate. Next, the team examined data on blood samples from several dozen males that had been sedated. They found a strong correlation between blood testosterone levels and mane color.
According to a recent news story in the New Scientist, 'handsome men have the best sperm'. And how do we know this? Because researchers recruited 66 women in Valencia, Spain, who looked at the faces of 66 male students and happened to identify as the most handsome those men who also have the best sperm. The authors of the study conclude: 'Our study has shown that women are able to recognize reproductively fit males on the basis of their facial appearance alone.'
It's difficult to see how they could come to such a conclusion. In the study, 66 women made a subjective assessment of the attractiveness of 66 men; and the men they judged to be most good looking happened to have more motile and more morphologically normal sperm. All the research shows, therefore, is that in a small sample of young men, good looks seems to correlate with good sperm. What we don't know from the New Scientist story is other information that might be relevant, such as how much the men smoke or drink. Intriguingly, the study doesn't show a correlation between good looks and a good sperm count - a measurement often used as an indicator of male fertility.
Studies such as these are becoming increasingly common in the media today. But why we are so interested in them? Perhaps drawing grand conclusions from such research findings fulfils a need in us to find causes for our behavior that are not the result of our own free will and for which, consequently, we don't have to take responsibility. In this case, our search for causes of human behavior that are beyond our control leads us to conclude that women are attracted to handsome men for sound biological reasons. It can't possibly be that we are simply driven by such shallow reasons as the desire to be surrounded by beautiful things, can it?
