Analyzes the relationship between the development of formal operations and the development of the adolescent personality, as hypothesized by Inhelder and Piaget. It is suggested that the concepts of possibility and reflectivity have a variety of meanings, and that once these meanings are examined, the logical foundation for the…

Spontaneous thematic play behavior in children is investigated. Environmental prerequisites of play and possible functions of play in cognitive and personality development are discussed. Whether modelling is a prerequisite for thematic play, and the relationship between level of play and creativity test performance in children are assessed. (DP)

Summarizes the theory of psychological differentiation and reviews recent cross-cultural research on the roles of child rearing, culture, and ecology in the development of individual, group, and sex differences in the field dependence-field independence cognitive style component of psychological differentiation. (SS)