Cognitive activity of children from 1.5 to 5 years of age participating in problem solving and in spontaneous play was analyzed in terms of the successive coordination of existing patterns and the incorporation of new mental components. Analysis identified a series of developmental levels. (Author/RH)

Assessed through two studies the organization and basis for preschool children's (n=240) and adults' (n=60) categorization of emotions. In one, children and adults chose facial expressions that exemplify emotion categories such as fear, anger, and happiness. In another they grouped emotions differing in arousal level or pleasure-displeasure…