The goals of this thesis were to: (1) provide additional validation of the Revised Social Goals Inventory; (2) examine predictors of maternal social beliefs; (3) test a conceptually-derived model linking maternal social beliefs, maternal behaviours promoting children's peer relations, and indices of children's peer engagement. Participants were N=262 mothers and children (aged 4-7), recruited from schools in south-eastern Ontario. Mothers reported on their own social beliefs, behaviours, and personality, and their children's temperament and peer activities. Additional measures were obtained from children and teachers. Results indicated the RSGI demonstrated good psychometric properties. Both maternal personality and child temperament predicted social beliefs. Maternal behaviours were found to mediate the link between social beliefs and children's peer engagement. Mediation effects differed as a function of type of maternal behaviour, child gender, and domain of children's peer activity. Results are discussed in terms of the role social beliefs play in children's social development.