In certain economic experiments, some participants willingly pay a cost to punish peers who contribute too little to the public good. Because such punishment can lead to improved group outcomes, this costly punishment has been conceived of as altruistic. Here, we provide evidence that individual variation in the propensity to punish low contributions is unrelated to altruism. First, individual use of punishment was uncorrelated with contribution to the public good, contrary to the hypothesis that punishers are proximally motivated by prosocial preferences. Second, individual use of punishment was positively correlated across situations where the use of punishment is typically group beneficial and situations where the use of punishment is typically group detrimental, as well as across situations of radically different strategic structures. These findings contrast sharply with the premise that the tendency to use punishment can fruitfully be regarded as an adaptation for solving social dilemmas.