Four features of early adolescent friendship have received the greatest attention in the literature: intimacy of conversations, friends' responsiveness to each other's needs and desires, the degree of similarity or complementarity between friends, and the stability of friendships over time. Each of these features and its potential effect on the…

Four studies examined the claim that preschoolers understood biological inheritance. Found that it was not until age seven that children demonstrated that they understood birth as part of a process selectively mediating the acquisition of physical traits and learning or nurturance as mediating the acquisition of beliefs. (MDM)

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…