First-grade children at risk for a learning disability (LD) in mathematics, reading, or both were compared to a control group on experimental tasks assessing number comprehension and production skills, counting knowledge, arithmetic skills, working memory, and ease of retrieving information from long-term memory. Found different patterns of intact…

Compared performance of 9-year-olds with arithmetic difficulties to that of age-matched and ability-matched controls on 10 tasks used to assess different aspects of working memory, including subtypes of executive function. Found deficits in executive and spatial aspects of working memory that seem likely to be important factors in poor…

Speeded performance on simple mental addition problems of 6- and 7-year-olds with and without mild mental retardation was modeled from a person perspective and an item perspective, both inferred from Siegler's work. Models from item response theory were used to test hypotheses. Found that all children follow same developmental path in acquiring…

Children from grades 2, 3, 4, 6, and 8 made speeded, bimanual parity (odd/even) judgments of numerals. Response times indicated that from fourth grade on, parity information was retrieved directly from memory. By grade 3, children represented magnitude information as a left-to-right number line which was accessed obligatorily and, by grades 6 and…

Examined whether preschoolers could recognize numerical equivalence for comparisons involving sequentially presented sets. Found that children recognized numerical equivalence for static sets earlier than for sequential sets. Memory of the number of sequentially presented objects emerged earlier than memory for the number of sequential events.…

Examined role of spontaneous gesture in 2- to 4-year-olds' counting and assessment of counting accuracy. Found that correspondence of children's speech and gesture varied systematically across age. Children adhered to one-to-one correspondence principle in gesture prior to speech. Counting accuracy related to correspondence of speech and gesture,…

This study compared 6- to 7-year-olds' knowledge of numerical fractions prior to school instruction in Croatia, Korea, and United States. Results suggested that the Korean vocabulary of fractions may influence the meaning children ascribe to numerical fractions and that this results in children being able to associated numerical fractions with…

Two studies examined preschool children's beliefs about maternal intention as a mechanism for trait inheritance. Study 1 indicated that preschoolers believe that maternal intention plays a role in inheritance of physical traits. Study 2 suggested that children see some properties as outside maternal control, and that maternal intention operates…

Two experiments investigated 4- to 7-year olds' memory for a specific episode of a repeated event. In Experiment 1, younger children had more difficulty remembering when a new activity type had been experienced, although experience improved memory for schema-atypical activities introduced in repeated events. Experiment 2 showed younger children…

Explored the effects of differences between English-language and Chinese numerical systems for naming months and days on calendar calculations. Chinese and U.S. 8- and 10-year olds and undergraduates were asked to name a date coming before or after another given date. Found that Chinese speakers used calculations; English speakers recited names.…

Three experiments examined 3- to 4-year olds' judgments about physical representations which no longer matched their references. Results showed that children tended to misidentify the name of a sticker in a written list to match a change to its referent. Children's incorrect judgments indicated that realist errors to external representations…

Examined 4-year olds' strategy development using a new kind of "same-different" judgment task that minimized memory demands. Found that children's spontaneous behavior was highly strategic, and over trials it developed differently for "same" and "different" trials. Most children who did not spontaneously use the most effective strategy could be…

Examined abilities of 3- to 16-year olds and adults to resist interference during the processing of two auditory dimensions of speech--the speaker's gender and spatial location. Found that the degree of interference from irrelevant variability in either dimension did not vary with age. In the presence of conflicting task-irrelevant information,…

Investigated the emergence of class and propositional reasoning skills as a function of the developing ability to coordinate increasingly complex negation and affirmation operations with children from grades 1, 3, 5, and 7. Found that children's reasoning follows a logical development sequence and that different groups of items account for…

Two experiments examined the effects of a culture-general factor, pattern redundancy, on the discrimination of five-tone melodies that differed in their adherence to Western tonal conventions, among 9-month olds, 5-year olds, and adults. Increasing exposure seemed to attenuate the effects of the pattern redundancy while amplifying the influence of…