ABSTRACT
The purpose of this chapter is to describe three studies that shed light on (1) the validity of our conceptualization of mastery motivation and (2) developmental changes in such motivation during infancy and toddlerhood. For each study, we first examine the relation between task persistence and task pleasure, indices of two central aspects of mastery motivation. Second, we examine correlates of persistence and pleasure, to help provide construct validation for them as measures of mastery motivation. Third, we examine continuities and changes in behaviour, to provide evidence regarding the development of mastery motivation between 6 and 30 months of age.
