Men motivated by 'superior wage'

On receiving a paypacket, how good a man feels depends on how much his colleague earns in comparison, scientists say.

Scans reveal that being paid more than a co-worker stimulates the "reward centre" in the male brain.

Traditional economic theory assumes the only important factor is the absolute size of the reward.

But researchers in the journal Science have shown the relative size of one's earnings play a major role.

In the study, 38 pairs of male volunteers were asked to perform the same simple task simultaneously, and promised payment for success.

Both "players" were asked to estimate the number of dots appearing on a screen. Providing the right answer earned a real financial reward between 30 (£22) and 120 (£86) euros. Each of the participants was told how their partners had performed and how much they were paid.