RESUMO
Mastery motivation is a psychological force that stimulates an individual to attempt to master a task that is challenging to him or her. This prospective longitudinal study examined the relationship between maternal stress, using the Parenting Stress Index-Short Form, and infant mastery motivation, using the Dimensions of Mastery Questionnaire, for 150 mother-infant pairs assessed at both 6- and 18-months of age. Infants of mothers with elevated stress levels at 6 months tended to show lower mastery motivation at 18 months (standardized beta=-.46, p=.001). Conversely, infants with lower general competence (standardized beta=-.24, p=.021) and lower persistence during social interactions with other children (standardized beta=-.18, p=.037) at 6 months of age had mothers with elevated total stress at 18 months of age. Implications for programs which simultaneously intervene with child and mother are discussed.