Using a genetic design of 840 60-month-old twins, this study investigated the genetic and environmental contributions to (a) individual differences in four components of cognitive school readiness, (b) the general ability underlying these four components, and (c) the predictive association between school readiness and school achievement. Results…

Stability in cardiac indicators before birth and their utility in predicting variation in postnatal development were examined. Fetal heart rate and variability were measured longitudinally from 20 through 38 weeks gestation (n = 137) and again at age 2 (n = 79). Significant within-individual stability during the prenatal period and into childhood…

This study uses latent class analysis (LCA) to empirically identify victimization groups during middle school. Approximately 2,000 urban, public middle school students (mean age in sixth grade = 11.57) reported on their peer victimization during the Fall and Spring semesters of their sixth, seventh, and eighth grades. Independent LCA analyses at…

Eighteen-month-olds' spatial categorization was tested when hearing a novel spatial word. Infants formed an abstract categorical representation of support (i.e., placing 1 object on another) when hearing a novel spatial particle during habituation but not when viewing the events in silence. Infants with a productive spatial vocabulary did not…

This training study investigates how children learn to refer to things unambiguously. Two hundred twenty-four children aged 2.6, 3.6, and 4.6 years were pre- and post-tested for their ability to request stickers from a dense array. Between test sessions, children were assigned to a training condition in which they (a) asked for stickers from an…

Knowledge about racism is a critical component of educational curricula and contemporary race relations. To examine children's responses to learning about racism, European American (Study 1; N = 48) and African American (Study 2; N = 69) elementary-aged children (ages 6-11) received history lessons that included information about racism…

This article uses longitudinal data from approximately 2,000 low-income families participating in the national evaluation of the Comprehensive Child Development Program to examine the associations between preschool children's living arrangements and their cognitive achievement and emotional adjustment. The analysis distinguishes families in which…

Do preadolescent sport self-concepts influence subsequent sport performance? Longitudinal data (Grades 3, 4, and 6) for young boys and girls (N = 1,135; mean age = 9.67) were used to test reciprocal effects model (REM) predictions that sport self-concept is both a cause and a consequence of sport accomplishments. Controlling prior sport…

Life history theorists have proposed that humans have evolved to be sensitive to specific features of early childhood environments and that exposure to different environments biases children toward development of different reproductive strategies, including differential pubertal timing. The current research provides a longitudinal test of this…

A social developmental framework was applied to test for the socialization of homophobic attitudes and behavior within adolescent peer groups (Grades 7-11; aged 12-17 years). Substantial similarity within and differences across groups were documented. Multilevel models identified a group socializing contextual effect, predicting homophobic…

The primary aim of the present study was to examine longitudinal models to determine the function that best describes developmental change in processing speed during childhood and adolescence. In one sample, children and adolescents (N = 503) were tested twice over an average interval of 2 years on two psychometric measures of processing speed:…

This study tests the firm distinction children are said to make between living and nonliving kinds. Three, 4-, and 5-year-old children and adults reasoned about whether items that varied on 3 dimensions (alive, face, behavior) had a range of properties (biological, psychological, perceptual, artifact, novel, proper names). Findings demonstrate…

For this study, information on "Who Bullies Who" was collected from 54 school classes with 918 children (M age = 11) and 13,606 dyadic relations. Bullying and victimization were viewed separately from the point of view of the bully and the victim. The two perspectives were highly complementary. The probability of a bully-victim relationship was…

Two hypotheses--high self-esteem leads children to act on antisocial cognitions (disposition-activating hypothesis) and high self-esteem leads children to rationalize antisocial conduct (disposition-rationalizing hypothesis)--were investigated in two longitudinal studies. In Study 1 (N = 189; mean age = 11.1 years), antisocial behavior was…

Factors that influence the incidence of utilization deficiencies and other recall/strategy-use patterns on a strategic memory task were evaluated in two hundred and fourteen 7- and 9-year-old children. Both utilization deficiencies and the incidence of children showing increases in both recall and strategy use over phases were more likely to be…