Evolutionary psychologists explain, however, that survival skills are inherent in our choice of a mate. According to this hypothesis, we are attracted to people who look healthy—for example, a woman with a 70 percent waist-to-hip ratio is attractive because she can likely bear children successfully. A man with rugged features probably has a strong immune system and therefore is more likely to give his partner healthy children.
On the other hand, perhaps our choice of a mate is a simple matter of following our noses. Claus Wedekind of the University of Lausanne in Switzerland conducted an interesting experiment with sweaty T-shirts. He asked 49 women to smell T-shirts previously worn by a variety of unidentified men. He then asked the women to rate which T-shirts smelled the best and which the worst.
He found that women preferred the smell of a T-shirt worn by a man who was the most genetically different form her. This genetic difference means that it is likely that the man’s immune system possesses something hers does not. By choosing him as the father of her children, she increases the chance that her children will be healthy.