In this study of the visual placing response (an extension of the paws or arms on approach to a visual surface), infants extended their arms almost as much to a gray surface as to a patterned one. (Author/CS)

Five experiments were conducted in order to determine what effect independent movement of an internal element has on the externality effect in young infants, and to consider the value of contrasting explanations of the effect itself. Subjects were 90 infants ranging in age from 28 to 49 days. (MP)

Two groups of infants were studied to demonstrate that changes in reaching are determined by the interaction of organismic and environmental constraints. The infants were placed in three different positions and observed for quantity and quality of reaching. Results indicated that both environmental constraints and growth contribute to reaching in…

Evaluated in three experiments a dynamic systems theory account of perseverative errors on "A-not-B" task. Found that 9-month-olds perseverated when reaching for identical targets, but made nonperseverative responses when reaching in the presence of a highly distinctive B target. Reach direction was jointly determined by target's…

Examined influence of child's sex on mothers' expectations about their 11-month-olds' motor development. Found that mothers of girls underestimated their performance on the novel task of crawling down steep and shallow slopes and mothers of boys overestimated their performance. Girls and boys exhibited identical levels of motor performance during…