Not being so mean keeps women keen

Modern-day man has developed a number of ways to prevent his female partner being unfaithful that compensate for his inability to keep watch over her every move.

Modern-day man has developed a number of ways to prevent his female partner being unfaithful that compensate for his inability to keep watch over her every move.

A man will display signs of jealousy, buy gifts and have more sex with his partner - all of which allow him, and her, to pursue their careers, a study presented at the American Psychological Society conference in Miami claims.

Evolutionary theory says that men have much to lose if their partner strays, because they could end up using their time and resources on another man's child. Dr Todd Shackelford, a psychologist at Atlantic University in Florida and one of the study's authors, said: "Men appear to be designed to be able to gauge the risk of infidelity and take appropriate action." He said that men were particularly sensitive to how much time they were spending with their partners, which he said was their "clearest predictor of infidelity".

Men who suspect or detect infidelity will employ "mate-guarding" techniques such as "being a nice guy" or buying gifts, he said. And if they still expecte that their partners will be unfaithful, they will launch a "sperm war" where their sperm count increases or they have more sex to give their genetic heritage a better chance than that of their rival.

"Men who are motivated to copulate sooner rather than later following a suspected infidelity stand to benefit enormously," Dr Shackelford said."Mate-guarding may be too costly or for other reasons may not be an option."