The Mouse Trap reports on a New Scientist article that looks at the roots of punishment and revenge.
Another article in the New Scientist , takes this one step forward and looks at motivations and mechanisms behind why we punish. The researcher, Terry Burnahm, asks the question as to why people indulge in a punishment behavior, though the punishment comes with a cost to themselves. Is it driven by a moral sense outrage, a desire for fairness or due to some other biological mechanism. The paradigm they use is the ultimatum game, wherein one person is given some money (say 10 $) and he is supposed to share it with another person. If the second person accepts the money, both get to keep the money; else both lose their money. Experimentally it is found that if low offers are made (say 1 $), they are usually rejected by the second person. This is due to the fact that the second personal wants to punish the first person for making an unfair offer.
What Terry discovered was that the propensity to refuse low offers was correlated with testosterone levels in males. Testosterone levels have also been correlated with aggression in the past and with dominance seeking behavior. The author suggests that the high testosterone connection is due to dominance seeking behavior of humans and by refusing to accept the low bet, the male saves putting himself in a subordinate position. It is presumed that this was beneficial in evolutionary times and thus has been selected for.
Link (Via Mind Hacks)