Proposes that humans may have evolved a special sensitivity to certain types of social information during rough-and-tumble play that facilitates social cognition. Describes the cognitive benefits of physical play as providing a break from demanding intellectual tasks and hypothesizes that physical play is related to gender differences in spatial…

Specifies some problems in the Piagetian characterizations of assimilation and accommodation and offers an alternative formulation intended to resolve some conceptual anomalies. On the basis of the revision, the orthogenetic law of developmental progression is explicitly derived. Further, Piaget's notion of "equilibrium" is extended into…

Provides an evolutionary account of the human affectional system. Warmth is conceptualized as a reward system which evolved to facilitate cohesive family relationships and paternal investment in children. Warmth must be distinguished from security of attachment. Relationships based on warmth can coexist with relationships based on exploitation.…

Comments on Belsky, Steinberg, and Draper's article in this issue. Discusses the claim for a connection of stressful childhood environments and early pubertal maturation. Argues that early puberty need not imply a shift from a "quality" toward a "quantity" reproductive strategy and that nonevolutionary factors can account for…

Argues that an evolutionary account provides insight into developmental function and individual differences. Outlines some assumptions of evolutionary psychology related to development. Introduces the developmental systems approach, differential influence of natural selection at different points in ontogeny, and development of evolved…