In the last two decades, an approach to the study of motivation has emerged that focuses on specific cognitive and affective mediators of behaviour, in contrast to more general traits or motives. This 'social-cognitive' approach grants goal-oriented motivation its own role in shaping cognition, emotion and behaviour, rather than reducing goal-directed behaviour to cold-blooded information processing or to an enactment of a personality type. This book adds to this process-oriented approach a developmental perspective. Critical elements of motivational systems can be specified and their inter-relations understood by charting the origins and the developmental course of motivational processes. Moreover, a process-oriented approach helps to identify critical transitions and effective developmental interventions. The chapters in this book cover various age groups throughout the life span and stem from four big traditions in motivational psychology: achievement motivation, action theory, the psychology of causal attribution and perceived control, and the psychology of personal causation and intrinsic motivation.