This book aims to provide the reader with a critical, synthetic, and systematic overview of theories concerning psychological complexity, self-generation of behavior, and personality development.

Developed in the United States (in Rochester and Chicago, respectively), Deci's and Ryan's self-determination theory and Csikszentmihalyi's optimal experience or flow theory are well-known in psychology. Indeed, they have brought many researchers to gather data and develop models and hypotheses regarding behavioral responses, motivational processes, and experiential states. However, these theories reveal their proper meaning only when considered from a wider perspective. Hence our overarching question is: How ought the above-mentioned theoretical contributions be inserted into a more general conceptual framework?

An initial development of these contributions is provided by considering general theories concerning the complexity and self-generation of behavior. Starting from evidence and data derived from other disciplines, such as biology and physics, we will emphasize psychological theories highlighting evolving, rather than homeostatic, aspects of behavior in order to avoid theoretical reductionism. Chapter 1 offers a series of reflections on this issue. It also elaborates on those conceptions that emphasize the central role of psychic functioning in the domain of biological and cultural evolution. By culture we mean the whole of human artifacts, from objects of daily use, to laws, to academic or political institutions.

This central role of psychic functioning needs to be viewed as two sets of mutually determining processes. On the one hand, biology and culture evolve due to numerous moments of daily psychological selection, meaning moments of specific organizations of experience by virtue of which individuals select, internalize, and transmit the biocultural information at hand.