In a range of species, females show clear preferences when it comes to the choice of their partner - they decide on the basis of external features like antler size or plumage coloration whether a male will be a good father to her offspring, or whether he will provide them with good genes. Erik Postma, an evolutionary biologist at the University of Zurich, has now demonstrated that humans have similar skills. The faces of riders that performed better during the Tour de France were deemed more attractive, showing that we can assess a men's endurance performance by looking at his face.
During the course of human evolution, hunting success and, by extension, feeding a family depended on the ability to chase game for hours and days. "That's why endurance performance was a key evolutionary factor", says Postma. Given the benefits a physically fit partner would have provided, the researcher hypothesised that facial attractiveness has evolved to signal, among others, endurance performance. If correct, then women should find those men who perform well in terms of endurance particularly attractive.
A comparison of 80 faces and cycling performance
To test this hypothesis, the scientist found his ideal study subjects in the participants of the 2012 Tour de France. "The Tour de France is the ultimate test when it comes to endurance performance", explains Postma. But although they are all top fit, there are still considerable differences in their performance. More than 800 people, both women and men, rated the portraits of 80 of the riders in terms of facial attractiveness, without knowing how fast they really were. Subsequently, the evolutionary biologist measured the performance of each rider on the basis of how long it took them to complete the three time trials and the complete race. He then related this to the attractiveness ratings each rider received and found that riders rated as more attractive had also fared better during the race. "Attractive riders are, therefore, faster", summed up Postma.
Hormones play an important role
The link between attractiveness and physical performance was strongest in women who were not using a hormonal contraceptive. These women found the faces of men who did well in the race to be particularly attractive. By contrast, the preference for fast riders was less pronounced in both women on the pill and in men. "These results are in line with other studies showing that hormones play an important role when assessing potential sexual partners", says Erik Postma from the Institute of Evolutionary Biology and Environmental Studies.