The sanctioning of norm-transgressors is a necessary--though often costly--task for maintaining a well-functioning society. Prior to effective and reliable secular institutions for punishment, large-scale societies depended on individuals engaging in 'altruistic punishment'--bearing the costs of punishment individually, for the benefit of society. Evolutionary approaches to religion suggest tha...

Pro-social punishment, whereby cooperators punish defectors, is often suggested as a mechanism that maintains cooperation in large human groups. Importantly, models that support this idea have to date only allowed defectors to be the target of punishment. However, recent empirical work has demonstrated the existence of anti-social punishment in public goods games. That is, individuals that defe...

Nearly half of U.S. parents use physical punishment for child discipline. Although some studies relate physical punishment and later dysfunction, others suggest that its effects depend on the context in which it is used. The authors analyzed data from the Commonwealth Fund Survey of Parents With Young Children, a national sample of 2,017 parents with children younger than 3. Parents reported th...

abstract The notion of invariant subspaces is useful in a number of theoretical and practical applications. In this paper we give an elementary treatment of invariant subspaces that stresses their connection with simple eigenvalues and their eigenvectors.

Experiments have shown that punishment enhances socially beneficial cooperation but that the costs of punishment outweigh the gains from cooperation. This challenges evolutionary models of altruistic cooperation and punishment, which predict that punishment will be beneficial. We compared 10- and 50-period cooperation experiments. With the longer time horizon, punishment is unambiguously benefi...

The Economics of Altruistic Punishment and the Demise of Cooperation Explaining the evolution and maintenance of cooperation among unrelated individuals is one of the fundamental problems in biology and the social sciences. Recent experimental evidence suggests that altruistic punishment is an important mechanism to maintain cooperation among humans. In this paper we explore the boundary condit...

Costly punishment of cheaters who contribute little or nothing to a cooperating group has been extensively studied, as an effective means to enforce cooperation. The prevailing view is that individuals use punishment to retaliate against transgressions of moral standards such as fairness or equity. However, there is much debate regarding the psychological underpinnings of costly punishment. Som...