This chapter provides an historical perspective about the growth of interest in mastery motivation. It describes the ways in which the terms have been employed and consider distinctions between them. The terms include mastery motivation, intrinsic motivation, competence motivation and, with older children, achievement motivation. The chapter outlines the theories of White, Hunt, Harter and Yarrow. Particular attention is paid to four issues: the conceptualizations of the goal-directed nature of motivation; the description of the relationship between intrinsic and extrinsic sources of motivation;. The relationship between motivation; and cognition, and the types of behaviour influenced by motivation. The chapter discusses the possibility that mastery motivation is one component of young infant's attentional system, and is related to habituation and novelty preference. The argument is developed that infant's attentional systems may be influenced by adult-infant interaction, which provides a means of increasing the ability to process information and extending infant attention span in exploration and persistence.