Suggests that, with the waning influence of Piaget and shortcomings of information-processing perspectives of cognitive growth, cognitive developmentalists lack a metatheory to guide their research. Posits developmental biology as metatheory for cognitive development. Introduces basic principles of evolutionary psychology, and examples of…

Argues that developmental psychologists need attitudes, methods, and conceptual schemes that integrate the distinctive contributions of both nature and nurture in order to study change and consistency in developmental functions, as well as individual differences in behaviors of interest. A conceptual scheme for early mental development is…

Piaget's class-inclusion task was revised class-inclusion tasks were administered to 64 kindergarten and 64 first-graders. Each of the revisions enhanced performance as compared with Piaget's standard procedures. These results are considered in terms of two possible interpretations. (Author/SDH)

Tests the hypothesis that the presence of attentional deficits in autistic children interferes with their performance on tests of intellectual development and status. Twelve autistic, 12 normal, and 12 trainable mentally retarded children ages four through nine were administered six "Piagetian" tasks assessing performance at…

Asserts that findings on whether young infants look longer at incorrect addition and subtraction have been inconsistent or negative. Hypothesizes that imprecise ordinal calculating with very small numbers of objects develops in late infancy and that precise calculating develops in early childhood. (Author/KB)