Aggressive behavior in English nurseries and play groups: sex differences and response of adults.

Aggressive behaviors were incident sampled in 5 nursery schools, 5 play groups, and 5 day nurseries in England. In 13 of 15 institutions, boys had a greater probability of being involved in aggressive incidents than girls. The initiator of an aggressive encounter was likely to be successful if there was no adult interaction, but to be unsuccessful if an adult intervened. There was no consistent evidence that adults intervened differentially in boy-boy, boy-girl, and girl-girl encounters.