Testosterone and ultimatum behavior

In a recent research paper, Terry Burnham investigated whether testosterone modulates behavior in the ultimatum game. Proposers and responders had to split $40. Proposers could either offer $25 or $5 out of 40, i.e, a fair or an unfair offer. It turns out that men with a higher level of testosterone are more prone to reject low offers than low-testosterone man:



Given that testosterone is associated with competition and dominance, Burnham interprets these results as indicating that low offers are construed as a challenge, and that high-testosterone men reply more aggressively.

Another--but closely related--interpretation would suggest not that high-testosterone men see low offers as a challenge (it not clear, by the way, how that could be a challenge), but rather that they are more irritated by a lack of fairness. They are more prone to punish those who do not behave fairly toward them by rejecting their offer.

see also a report in The Economist.

• Burnham, Terence C. High-testosterone men reject low ultimatum game offers. Proceedings of the Royal Society B: Biological Sciences.
  

see also a report in The Economist.