Children's acquisition of tool use abilities is an important part of development but is not yet well understood. This study compares two modes of tool-use learning, observation and individual haptic experience. Two- and 3-year-olds had haptic experience with tools, observed tool use by others, had both haptic and observational experience, or no…

We compared the performance of 3- and 5-year-old children with that of chimpanzees in two tasks requiring collaboration via complementary roles. In both tasks, children and chimpanzees were able to coordinate two complementary roles with peers and solve the problem cooperatively. This is the first experimental demonstration of the coordination of…

In three experiments, children aged between 3 and 5 years (N = 38, 52, 94; mean ages 3-7 to 5-2) indicated their confidence in their knowledge of the identity of a hidden toy. With the exception of some 3-year-olds, children revealed working understanding of their knowledge source by showing high confidence when they had seen or felt the toy, and…

Studied development of procedural knowledge in 14 adults, aged 18 to 35 years, engaged in a novel task using a toy tractor-trailer rig. Results revealed three phases of development in subjects' knowledge of steering procedures and the rig's movement patterns, and their use of feedback information. Subjects also manifested different levels of…

Relations among patterns of conceptual and procedural knowledge and grade were examined in 90 six- to eight-year-olds in order to explore addition and subtraction development. Conceptual knowledge was assessed by examining children's responses to pairs of problems reflecting various part-whole relations. Children solved related problems as part of…