Evidence indicates that the newborn infant must first develop cognitive systems, through his experience with various stimuli, to differentiate each modality separately before he can integrate any two modalities in classical conditioning. (Author/NH)

Preschool play behavior of today was compared with play norms collected more than 40 years ago. Present play behavior was judged to be significantly less social. (NH)

A series of investigations were conducted to determine whether reflexive crying occurs in newborns and to define the parameters that control his behavior. (NH)

The effect of subject age, sex, examiner, and stimulus word differences on developmental sequences of idiodynamic set responses in children's word associations was investigated. Subjects were 100 children, ages 7-11. The findings could not be interpreted as evidence of stage progressions, or hierarchical rankings in mediational processes. (NH)

To test the hypothesis that children learn concepts better through linguistic cues than through exemplars, 58 kindergarten children in four matched groups were taught four new concepts using different combinations of sentences and exemplars. Neither main effect, variety of exemplars, nor level of linguistic context was significant. However, a…

Reports on an experiment which involved 42 7 1/2-10 1/2-month-old infants playing a two-position hidden-object game. Results were interpreted to support and extend previous explanations of Stage IV of object-concept development. This report is a revised version of a paper presented at the biennial meeting of the Society for Research in Child…

Reinforcement conditions of approval, disapproval, or silence were used during a discrimination task assigned to 96 boys and 96 girls. Children receiving criticism responded at slower rates and made more errors than children receiving praise or silence. Retention was measured after 8 days. Results suggest that disapproval negatively affects both…