The author shows how simple models based on mutual interactions between children and their environments explain not only smooth evolutions but also sudden jumps, temporal regressions, cycles and chaotic change in cognitive and language development. A central concept of the system is non-linearity - small causes can have big effects and variables may be sensitive to threshold effects.

This book presents a thorough overview of a model of human functioning based on the idea that behavior is goal-directed and regulated by feedback control processes. It describes feedback processes and their application to behavior, considers goals and the idea that goals are organized hierarchically, examines affect as deriving from a different kind of feedback process, and analyzes how success expectancies influence whether people keep trying to attain goals or disengage. Later sections consider a series of emerging themes, including dynamic (...) systems as a model for shifting among goals, catastrophe theory as a model for persistence, and the question of whether behavior is controlled or instead 'emerges'. Three chapters consider the implications of these various ideas for understanding maladaptive behavior, and the closing chapter asks whether goals are a necessity of life. Throughout, theory is presented in the context of diverse issues that link the theory to other literatures. (shrink)