Research on early physical reasoning has shown surprising discontinuities in developmental trajectories. Infants possess some skills that seem to disappear and then re-emerge in childhood. It has been suggested that prediction skills required in search tasks might cause these discontinuities (Keen, 2003). We tested 3.5- to 5-year-olds'…

We discuss the limitations of hypothesis testing using (quasi-) experiments in the study of cognitive development and suggest latent variable modeling as a viable alternative to experimentation. Latent variable models allow testing a theory as a whole, incorporating individual differences with respect to developmental processes or abilities in the…

The present study investigated the role of the causal status of features and feature type in biological categorizations by young children. Study 1 showed that 5-year-olds are more strongly influenced by causal features than effect features; 4-year-olds exhibit no such tendency. There therefore appears to be a conceptual change between the ages of…

Young children's integration of weight and distance information was examined using a new methodology that combines a single-armed apparatus with functional measurement. Weight and distance values were varied factorially across the item set. Children estimated how far the beam would tilt when different numbers of weights were placed at different…

Items studied as pictures are better remembered than items studied as words even when test items are presented as words. The present study examined the development of this picture superiority effect in recognition memory. Four groups ranging in age from 7 to 20 years participated. They studied words and pictures, with test stimuli always presented…

Examined development of ability to inhibit thoughts within free speech by manipulating the content requirements of overt streams-of-consciousness. Investigation with kindergartners, second graders, fifth graders, and adults revealed a developmental improvement in inhibitory ability over the middle-childhood years; results are consistent with…

Switching between tasks produces decreases in performance as compared to repeating the same task. Asymmetrical switch costs occur when switching between two tasks of unequal difficulty. This asymmetry occurs because the cost is greater when switching to the less difficult task than when switching to the more difficult task. Various theories about…

Two experiments examined theory of mind in middle childhood by examining changes in the organization of mental verbs of knowing. Found that older children and comprehension monitors placed greater emphasis on the certainty aspects of mental activity than did younger children and comprehension nonmonitors, suggesting that important aspects of a…

Tested 13-, 16-, and 20-month olds' and 24- and 28-month olds' categorization of global- and basic-level object sets composed of prototypical and nonprototypical exemplars. Findings offer new information on the effects of prototypicality and on the process of differentiation of early global categories into more specific basic-level ones. (DR)

Examined nascent understanding of desire in cases where a child judges another's desire while holding a strong conflicting desire. Found that difference in ability to attribute beliefs versus desires to others is not due solely to difference in representational nature of two mental states; instead, beliefs differ from desire in their potential to…

Implicit understanding of false belief was investigated by monitoring where preschoolers looked in anticipation of a protagonist reappearing, when the protagonist mistakenly thinks that his desired object is in a different place from where it really is. Two-year olds erroneously looked at the object's real location whereas most older children…

Reviews "The Language Instinct: How the Mind Creates Language" (S. Pinker). Defines generative grammar, examines the evidence for Pinker's Generative Grammar as Instinct hypothesis, and discusses Pinker's use of language acquisition as support for the hypothesis. Suggests alternative theories of language that begin from different…

Three experiments (sorting and theory-of-mind tasks) examined whether, for preschoolers, a particular form of reasoning applied to theory-of-mind and a set of problems requires understanding of mental states. Found that advances in theory of mind, card sorting, and causality depend on ability to switch judgments across conditions; reasoning by…

Previous research suggests that not until about age six do children recognize that one can gain knowledge through inferential rather than direct means. Three experiments were conducted in which important task information was made more salient to determine whether children's performance in previous research on their understanding of inference had…

Tested children with apparatus that dropped balls through clear or opaque interwoven tubes. Found that older children could solve configurations with greater number of tubes than younger children. Success with clear tubes did not transfer to opaque tubes. Significantly, errors were consistently directed to location directly below ball's last seen…