Costly punishment, in which one person punishes another at a cost to himself, rarely pays off. In cooperation games, those who engage in costly punishment do not benefit from their behavior individually, and the use of punitive behavior bestow no benefit on the group as a whole. In an extremely competitive setting, the winners are those who resist the temptation to escalate conflicts, while the losers punish and perish. These results demonstrate that costly punishment is not an effective force for promoting cooperation, and our tendency to engage in acts of spiteful punishment must have evolved for other reasons, such as establishing a dominance hierarchy or defending ownership.
