Reviews research which demonstrates that responses from different behavior systems to a given stimulus situation may be far from perfectly correlated with each other. Discusses the phylogenetic and ontogenetic development of these systems and the roles of both the species and the individual in bringing the systems into mutual correspondence.…

This review argues that an hypothesis about longitudinal development may be derived from, and tested exclusively by, cross-sectional data, when the potential sources of interpretive errors are dealt with adequately. The argument is illustrated by cross-sectional data relevant to developmental mediation theory. (Author/SS)

Studies the effects of perceptual salience on performance in problems requiring the coordination of information. Subjects were groups of children, younger adults, and older adults. For each of the age groups, those problems containing the most salient information were solved faster and more accurately than problems containing the least salient…