Mastery Motivation in Young Children with Williams Syndrome or Down Syndrome

Abstract Mastery motivation supports goal-directed behavior and contributes to learning and development, yet little is known about this construct in children with intellectual and developmental disabilities. This study – the first to examine mastery motivation in individuals with Williams syndrome (WS) – compared 31 preschoolers with WS (M age =4.12 years) to 31 preschoolers with Down syndrome (DS; M age =4.22 years) using both a task-based observational measure of mastery motivation and a parent-report questionnaire. Standardized measures of intellectual ability and adaptive behavior were also administered. Children with WS demonstrated significantly less mastery persistence and mastery pleasure than children with DS on the task-based measure, despite having significantly higher overall intellectual ability. The groups did not differ significantly on task-based competence. Parents rated children with WS significantly lower than children with DS on overall persistence and general competence but not on mastery pleasure. Relative to the norming sample for the parent measure, both syndrome groups had lower overall persistence and general competence but did not differ significantly on mastery pleasure. Task-based and parent-reported measures of corresponding mastery motivation constructs were not significantly correlated, suggesting they capture different aspects of behavior across contexts. In a multiple regression, overall intellectual ability and parent-reported overall persistence each accounted for significant unique variance in adaptive behavior, whereas syndrome group did not. These findings establish mastery motivation as a meaningful developmental construct in children with WS and DS, beyond consideration of intellectual ability and diagnosis, and highlight the importance of assessing its instrumental and expressive/affective components across both structured and everyday contexts.