Behavioral flexibility--the ability to tailor motor actions to changing body-environment relations--is critical for functional movement. Navigating the everyday environment requires the ability to generate a wide repertoire of actions, select the appropriate action for the current situation, and implement it quickly and accurately. We used a new,…

Although algebra is a prerequisite for higher mathematics, few studies have examined the mathematical and cognitive capabilities that contribute to the development of algebra word problems solving skills. We examined changes in these relations from second to ninth grades. Using a cross-sequential design that spanned 4 years, children from 3…

These experiments explored the role of prior experience in 12- to 18-month-old infants' tool-directed actions. In Experiment 1, infants' use of a familiar tool (spoon) to accomplish a novel task (turning on lights inside a box) was examined. Infants tended to grasp the spoon by its handle even when doing so made solving the task impossible (the…

Examined the relationship between 6- to 8-year olds' conceptual understanding of additive composition, commutativity, and associativity principles and addition problem-solving procedures. Results revealed that conceptual understanding was related to using order-indifferent, decomposition, and retrieval strategies and speed and accuracy in solving…

Three experiments tested 21- and 27-month olds' ability to construct a path to a mentally re-presented goal. After seeing the goal-state configuration of problems, both age groups evinced planning. Demonstration of initial solution step was less effective than goal-state exposure. Even with specification of a greater proportion of the goal path,…

Reflective subjects generated characteristically different and more efficient hypothesis-testing strategies than impulsive subjects. (Author)

A sample of 86 college students aged 18 to 35 years of age were asked to solve three formal operations tasks and to participate in a problem-finding task. No relation was found between performance on problem-finding and the formal operations task. (JMB)

Three experiments examined the role of representations in adolescents' deductive reasoning. Findings indicated that, with age, conditional reasoning improved on tasks containing permission conditional relations; reasoning fallacies increased on tasks containing causal conditional relations. Valid conditional inferences were more common on problems…

Purpose of this study was to determine whether some major aspects of children's role-playing behavior can be coded reliably and whether role-playing behavior is related to role-problem characteristics and individual variables. (Authors)

Two marble-and-ramp experiments investigated whether a simple-to-embedded-rules account can explain changes in children's causal reasoning. Results indicated that the same difference between three- and four-year olds in the prediction experiment appeared in the action experiment, suggesting that the same rules may underlie causal action as well as…

Examined patterns of conceptual and procedural knowledge of addition in 5- to 8-year-olds. Found that children were more successful in noticing that addends had been reordered rather than decomposed and in noticing the decomposition of addends presented with objects rather than with symbols. Also found that profiles of procedural competence were…

Examines a model for children's strategies for inclusion tasks. Suggests that young children are not consistent in task strategies and that they display mixed response strategies. Strategies may change with development. (ET)

Three experiments explored the development of formal logical reasoning between Grades 4 and 12 and the role of semantic content in the solution of Wason's (1966) selection task problems. Results suggest that formal logical reasoning is not generally present during the fourth or sixth grades and that formal logical competence becomes available in…

It was shown that hierarchies change with development and that relative salience of a dimension is negatively associated with both reaction time of choice and number of errors on the identity task. (Authors)