Outcomes and intentions in children's, adolescents', and adults' second- and third-party punishment behavior.

Theories of morality maintain that punishment supports the emergence and maintenance of moral behavior. This study investigated developmental differences in the role of outcomes and the violator's intentions in second-party punishment (where punishers are victims of a violation) and third-party punishment (where punishers are unaffected observers of a violation). Four hundred and forty-three adults and 8-, 12-, and 15-year-olds made choices in mini-ultimatum games and newly-developed mini-third-party punishment games, which involved actual incentives rather than hypothetical decisions. Adults integrated outcomes and intentions in their second- and third-party punishment, whereas 8-year-olds consistently based their punishment on the outcome of the violation. Adolescents integrated outcomes and intentions in second- but not third-party punishment.