Pretty people are not inclined to cooperate. When people will do what you want because you’re better looking, why compromise?

Santiago Sanchez-Pages, who works at the universities of Barcelona and Edinburgh, and Enrique Turiegano, of the Universidad Autónoma de Madrid, base their claims on the “prisoner’s dilemma” model of behaviour, played out under laboratory conditions. Two players were each given the option of being a “dove” and co-operating for the greater good; or a “hawk”, taking the selfish option, with a chance of gaining more if the other player chose “dove” and co-operated. The subjects’ faces were then analysed.

The study found that people with more symmetrical faces were less likely to co-operate and less likely to expect others to co-operate. The findings will be presented at the annual Nobel Laureate Meetings in Lindau, Germany, from 23 to 27 August.

The explanation may be found in evolution. The two academics speculate that, on a subconscious level, people tend to view symmetrical physical attributes as a sign of good health and find people with them more attractive as a result. Earlier studies have suggested that individuals with symmetrical faces tend to suffer fewer congenital diseases and therefore make better potential mating partners. As a result, the studies suggest, they are more self-sufficient and have less need for seeking the help of others.