This study investigated the extent to which class-specific parameter estimates are biased by the within-class normality assumption in nonnormal growth mixture modeling (GMM). Monte Carlo simulations for nonnormal GMM were conducted to analyze and compare two strategies for obtaining unbiased parameter estimates: relaxing the within-class normality…

Numerical comparison is a primary measure of the acuity of children's approximate number system. Approximate number system acuity is associated with key developmental outcomes such as symbolic number skill, standardized test scores, and even employment outcomes (Halberda, Mazzocco, & Feigenson, 2008; Parsons & Bynner, 1997). We examined…

Objective: Children's health beliefs are significantly related to their adherence; however, pediatric literature has rarely tested health-related theories as a whole. The goal of the present study was to evaluate the use of the health belief model (HBM) in understanding children's adherence, both globally and to individual treatment components.…

Purpose: We aimed to outline the latent variables approach for measuring nonverbal executive function (EF) skills in school-age children, and to examine the relationship between nonverbal EF skills and language performance in this age group. Method: Seventy-one typically developing children, ages 8 through 11, participated in the study. Three EF…

Longitudinal data from a large sample of twins participating in the Netherlands Twin Register (n = 42,827, age range 3-16) were analyzed to investigate the genetic and environmental contributions to childhood aggression. Genetic auto-regressive (simplex) models were used to assess whether the same genes are involved or whether new genes come into…

Purpose: This study used a computational vocal tract model to investigate the relationship of diphthong duration and vocal tract movement magnitude to measures of the F2 trajectory in CV words. Method: Three words ("bough," "boy," and "buy") were simulated on the basis of an adult female vocal tract model, in which…

Children with Specific Language Impairment (SLI) have language difficulties of unknown origin. Syntactic profiles are atypical, with poor performance on non-canonical structures, e.g. object relatives, suggesting a localized deficit. However, existing analyses using ANOVAs are problematic because they do not systematically address unequal…

Representations of numerical value have been assessed by using bounded (e.g., 0-1,000) and unbounded (e.g., 0-?) number-line tasks, with considerable debate regarding whether 1 or both tasks elicit unique cognitive strategies (e.g., addition or subtraction) and require unique cognitive models. To test this, we examined how well a mixed log-linear…

Objective: Accurate estimation of developmental trajectories can inform instruction and intervention. We compared the fit of linear, quadratic, and piecewise mixed-effects models of reading development among students with learning disabilities relative to their typically developing peers. Method: We drew an analytic sample of 1,990 students from…

This study investigates the role of perspective-taking skills in how children explain spatially complex astronomical phenomena. Explaining many astronomical phenomena, especially those studied in elementary and middle school, requires shifting between an Earth-based description of the phenomena and a space-based reference frame. We studied 7- to…

Background: Although callous-unemotional (CU) traits have been associated with bullying among children and adolescents, relatively little is known about whether each of the three sub-constructs of CU traits--callous, uncaring, and unemotional--are associated with bullying when they are considered concurrently in the analysis. Objective: This study…

Background: Despite the benefits of social participation, children and adolescents with developmental disabilities (DD) are often excluded from taking part in social activities. There is a gap in the literature about the factors that contribute to adequate participation of children with severe DD in particular and the barriers to their…

Because of the continued increase in obesity rates and decrease in children's physical activity and fitness levels, this study investigated the relationship between habitual physical activity and perceived competence, enjoyment of physical activity, and cardiorespiratory fitness among upper elementary school children. This study used the…

The article presents the results of an analysis of the moral value judgments of adults (parents, teachers, educators) that directly concern the socialization process of the young generation in the modern metropolis. This paper follows the model study by Jean Piaget that investigated the moral value judgments of children. A comparative analysis of…

This study investigates whether age-related changes in the structure of 5 complex working memory (WM) tasks (a) reflect a general or domain specific system, (b) follows a similar trajectory across different age spans, and (c) contribute domain general or domain specific resources to achievement measures. The study parsed the sample (N = 2,471)…