Nature magazine reports that macho, testosterone men tend to drive a hard bargin, unless they have been exposed to images like the one below.

Researchers at the University of Leuven in Belgium asked men to play an ultimatum game, in which they split a certain amount of money between them. High-testosterone men drove the hardest bargain — unless they had previously viewed pictures of bikini-clad models, in which case they were more likely to accept a poorer deal.

The sight of flesh had less effect on the bargaining tactics of low-testosterone men.