By Nick Collins, Science Correspondent 4:47PM GMT 02 Feb 2012
Men become more generous when attractive women are around because they want to impress them, a study claims.
Just as a peacock reveals its spectacular plumage when it spots a female, men are more likely to show off by doing good deeds if they are in the company of attractive members of the opposite sex.
A study showed that men actively compete to outdo each other with generous acts when being watched by attractive women, and not when observed by other men.
But the same does not apply to women, whose selflessness remains the same whether in the company of men or other women, psychologists from Oxford and Sheffield Hallam universities found.