A person's attitude to sex might be written all over their face, according to a study of attractiveness. Psychologists also found that, when it comes to selecting relationships, heterosexual men and women are looking for entirely opposite things.

"What was interesting was the strength of the preference among men for women who were interested in short-term sex and the strength of the preference of the women for men not interested in short-term sex," said Lynda Boothroyd of Durham University, who led the study.

Researchers surveyed 700 men and women in their early 20s, who were asked to look at photographs of the opposite sex and judge how attractive they were and what their attitudes to sex might be - such as whether they were interested in long or short-term relationships. The answers were compared with the real-life behaviour and attitudes of the people in the images.

The results, published in the journal Evolution and Human Behaviour, showed that men and women could generally judge who would be more interested in a short-term fling just by looking at their expression and features. In one study of 153 participants, 72% of people correctly identified the attitudes from photographs more than half of the time. "Men who said they were interested in short-term sex were seen as looking more masculine," said Boothroyd.