Multilevel selection theory and major evolutionary transitions

ABSTRACT—The concept of a group as comparable to a single organism has had a long and turbulent history. Currently, methodological individualism dominates in many areas of psychology and evolution, but natural se-lection is now known to operate at multiple levels of the biological hierarchy. When between-group selection dom-inates within-group selection, a major evolutionary tran-sition occurs and the group becomes a new, higher-level organism. It is likely that human evolution represents a major transition, and this has wide-ranging implications for the psychological study of group behavior, cognition, and culture. KEYWORDS—group selection; human evolution; multilevel selection theory; group psychology; culture The concept of a social group as a single organism has a lon