This study tests the hypothesis that components of play such as immagination contribute to cognitive development. Twenty-four middle-class children attending a university-affiliated preschool were observed for 20 one-minute play observations during the Spring Semesters of 1978 and 1979. Play was coded using categories for both social (solitary,…

An extension of discrimination-learning theory based on the inhibition of stimulus intensity was proposed and supported as a mechanism of cognitive development. Among 48 normal and 37 educable mentally retarded children the predominant category of transistional children conserved at a low level of stimulus intensity but failed to conserve at a…

The four purposes of this study were (1) to test the long-range effects of classification training (CT) on disadvantaged black children, (2) to evaluate the effects of reintroducing CT to those previously trained, (3) to compare CT at two age periods (5 and 6 years old), and (4) to compare CT with attention training (AT). Of the 69 children used…

This study attempted to develop a valid instrument for the assessment of attitudes in kindergarten children and to evaluate two potential curriculum procedures for facilitating attitude growth. One experimental treatment evolved from role-theory and emphasized perceptual awareness and the ability to put oneself in the place of another; the other…