Men perform good deeds to impress the opposite sex While carrying a stranger's suitcase up a flight of stairs may seem like a selfless act, a study found that for men it may in fact be a case of "peacocking," or showing off to the opposite sex. Men will actively compete to outdo each other with generous acts when being watched by women, making more and larger displays of generosity if they are attracted to them, researchers from Sheffield Hallam and Oxford universities found. They asked a group of men and women to play a computer game in which each participant was given £3. They could either invest it in a shared fund which would later be doubled and shared between six players - or keep it for themselves. Men donated much more often when the game was being observed by a woman, and the size of their contribution was directly linked to how attractive they judged her to be. Women's selflessness remained the same whether they were being watched by women, men or nobody. The study, published in the British Journal of Psychology. suggests that men will compete with each other through public good deeds to impress women - and spend more time doing so.