The Dimensional Change Card Sort (DCCS) task requires children to switch from sorting cards based on shape or color to sorting based on the other dimension. Typically, 3-year-olds perseverate, whereas 4-year-olds flexibly sort by different dimensions. Zelazo and colleagues (1996, Cognitive Development, 11, 37-63) asked children questions about the…

Category formation lies at the heart of a number of higher-order behaviors, including language. We assessed the ability of human adults to learn, from distributional information alone, categories embedded in a sequence of input stimuli using a serial reaction time task. Artificial grammars generated corpora of input strings containing a…

Looking-time studies examined whether 11-month-old infants can individuate two pairs of objects using only shape information. In order to test individuation, the object pairs were presented sequentially. Infants were familiarized either with the sequential pairs, disk-triangle/disk-triangle (XY/XY), whose shapes differed within but not across…

A preschool curriculum for lower class children was developed based on Piaget's theory. Evaluation procedures were developed to parallel a Piagetian curriculum. According to Piagetian theory, the mechanism of classification is the coordination of the intensive and extensive properties of a group of objects. The ability to dichotomously classify…

An overview is provided of the similarities and distinctions between individuals with autism and those with Asperger syndrome (AS). The cognitive and neurocognitive profiles underlying deficits characteristic of autism spectrum disorders are reviewed and particular emphasis is placed on comparisons of high-functioning autism to AS on the basis of…

Presented are the results of an investigation of stimulus integration capabilities of three- and four-year-old children in judgments of small and large numbers. There is much evidence that suggested young children have a concept of number for small numbers, but not for large ones. A concept of number was hypothesized by Piaget to rest on the…

Variation is a key concept in the study of statistics and its understanding is a crucial aspect of most statistically related tasks. This study aimed to extend and apply a hierarchy for describing students' understanding of variation that was developed in a sampling context to the context of a natural event in which variation occurs. Students aged…

This study identified behaviors of sibling pairs interacting on a cognitive task and related these behaviors to sibling structure variables (age and sex of each sibling and age spacing between them) and to measure of cognitive abilities of the younger sibling. Subjects were 160 sibling pairs randomly selected from appropriate subpopulations of…