Children should engage in 1 hr/day of moderate-to-vigorous physical activity (MVPA) that results in increased heart rates (HRs) (CDC, 2022). However, precise individualized HR criteria for MVPA are not provided, and it is unclear whether observed behaviors classified as MVPA are associated with elevated HRs indicative of MVPA. The current study…

Background: Speech in individuals with cleft lip and/or palate (CLP) is a complex myriad of presenting symptoms. It is uniquely associated with the structural difference of velopharyngeal insufficiency (VPI), together with a wide and heterogeneous range of other aetiologies which often co-occur. The nature of the speech sound disorder (SSD)…

The overall pattern of vocabulary development is relatively similar across children learning different languages. However, there are considerable differences in the words known to individual children. Historically, this variability has been explained in terms of differences in the input. Here, we examine the alternate possibility that children's…

In this 8-year longitudinal study, we traced the vocabulary growth of Chinese children, explored potential precursors of vocabulary knowledge, and investigated how vocabulary growth predicted future reading skills. Two hundred and sixty-four (264) native Chinese children from Beijing were measured on a variety of reading and language tasks over…

The adaptive calibration model (ACM) is an evolutionary-developmental theory of individual differences in stress responsivity. In this article, we tested some key predictions of the ACM in a middle childhood sample (N = 256). Measures of autonomic nervous system activity across the sympathetic and parasympathetic branches validated the 4-pattern…

The numerous temperament and personality constructs in childhood impede the systematic integration of findings on how these individual differences relate to developmental psychopathology. This paper reviews the main temperament and personality theories and proposes a theoretical taxonomy representing the common structure of both temperament and…

Fuzzy trace theory explains why children do not have to use rules of logic or premise information to infer transitive relationships. Instead, memory of the premises and performance on transitivity tasks is explained by a verbatim ability and a gist ability. Until recently, the processes involved in transitive reasoning and memory of the premises…

Individual differences in children's performance on a classification task are modeled by a two component binomial mixture distribution. The model accounts for data well, with variance accounted for ranging from 87 to 95 percent. (RJC)

This study examined the effect of exemplar typicality on reaction time and accuracy of categorization. High-functioning children (age 9-12), adolescents (age 13-16), and adults with autism (age 17-48) and matched controls were tested in a category verification procedure. All groups showed improved processing throughout the lifespan for typical and…

This study examined effects of individual differences in speak-span scores and variations in memory demands on class-inclusion performance of 10-, 13-, and 15-year-olds. Results from regression analyses and the mathematical model indicated that differences in age, speak span, and memory load affected performance. Effects of speak span and memory…

Three studies examined the ability of 8- and 9-year-olds and young adults to use sample monotonicity and diversity information according to the similarity-coverage model of category-based induction. Found that children's difficulty with this information was independent of category level, and may be based on preferences for other strategies…

The case is made for basing analysis of longitudinal data on each subject's curve of scores. In this analysis of IQ scores from a longitudinal study, fitted curves yielded significant error reduction, rendering untenable the doctrine of IQ constancy. A visual method of curve classification is also presented. (Author/SJL)

A series of Piagetian concrete operations period tasks dealing with classificatory concepts was administered to 280 children (40 subjects from each of seven levels--preschool, kindergarten, and first, second, third, fourth, and sixth grades). Significant main effects for age were found for all the tasks. Few significant sex differences were…

The research reported here was designed to measure the abilities of school-age children to form and generalize "visual concepts" on the basis of their observation of prepared sets of art reproductions. The art reproduction sets displayed similarities based upon various visual attributes. Discrimination of the attributes common to any…