It seems that the more macho a man is — at least according to his hormones — the more the sight of an attractive woman will affect his judgement.

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.