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...

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.

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...

The trade-off between mercy and justice is a classic moral dilemma, particularly for organizational leaders and managers. In 3 complementary studies, we investigated how resolving the "punishment dilemma" influences interpersonal trust. Study 1 used controlled scenarios to show that uninvolved observers trusted leaders who administered large or medium punishment more than leaders who administer...