In this book Heckhausen and Heckhausen give an extensive and in-depth overview of the diverse lines of research in motivational psychology, in terms of its historical foundations, up-to-date conceptual developments and empirical research. The major classes of motivated behavior, such as achievement, affiliation and power, are addressed and the critical processes involved in motivation and volition are discussed in detail. Different conceptual and empirical lines of research, such as implicit/explicit motivation, intrinsic/extrinsic motivation/volition, causal attribution, childhood and lifespan development, education, personality and psychopathology are integrated and analyzed as to the common issues and phenomena they address, thus providing a most useful guideline for understanding debates in current motivational, educational and social psychology.