We examined the development of numerical magnitude representations of fractions and decimals from fourth to 12th grade. In Experiment 1, we assessed the rational number magnitude knowledge of 200 Chinese fourth, fifth, sixth, eighth, and 12th graders (92 girls and 108 boys) by presenting fraction and decimal magnitude comparison tasks as well as…

Guided by the life course perspective, this study investigated the developmental antecedents of contact, closeness/warmth, and negativity in young adults' relationships with their parents. Taking the developmental systems approach, we considered interindividual differences in not only initial levels of parenting quality in early adolescence (Grade…

Tenets of the Boivin et al. (1995) social process model were reexamined with two longitudinal samples using both the original and contemporary analytic strategies. Study goals included reconstructing (e.g., quasireplicating) Boivin et al.'s (1995) original findings and evaluating hypothesized relations across both comparable and longer…

Antisocial peer behavior and low parental knowledge of adolescents' activities are key interpersonal risk factors for adolescent substance use. However, how the magnitude of associations between these risk factors and substance use may vary across adolescence remains less well understood. The present study examined the age-varying associations of…

This research explored whether experiences with warmth in middle childhood are linked to increased levels of positive affect, decreased levels of negative affect, and decreased levels of disagreeable interactions in text-message communication in adolescence. Participants included 218 children (and their parents and peers) who were on average…

This study examines developmental change across adolescence in the similarity of friends versus nonfriends. This differential in similarity is a key aspect of the organization of the peer context of development: The stronger the correlation between friends for an attribute, the more the attribute delineates clustering and divisions of friendships.…

Longitudinal links between early childhood temperament, maternal sensitivity, and adolescents' adjustment have been proposed and found in several longitudinal studies, but the mechanisms of influence have not been explored. The authors examined the paths from maternal sensitivity and temperament in early childhood to adolescents' prosocial,…

Research has shown that the average values for academic interest decrease during adolescence. Looking beyond such quantitative decline, we explored qualitative change of interest in the domain of mathematics across adolescence. Study 1 was based on a longitudinal data set (annual assessments from Grade 5 to Grade 9; N = 3,193). Latent variable…

During the transition to adolescence, several developmental trends converge to increase the importance of peer relationships, the likelihood of peer-related stressors, and the experience of depressive symptoms. Simultaneously, there are significant changes in parent-child relationships. The current study sought to evaluate whether positive…

Using a sample of 767 children (403 girls, 364 boys), this study aimed to (a) identify groups with distinct trajectories of peer victimization over a 6-year period from primary school through the transition to secondary school, and (b) examine the associated personal (i.e., aggression or internalizing problems) and familial (family status,…

We tested 2 hypotheses derived from Moffitt's (1993) taxonomic theory of antisocial behavior, both of which are central to her explanation for the rise in delinquency during adolescence. We tested whether persistently delinquent individuals become more accepted by their peers during adolescence and whether individuals who abstain from delinquent…

Prospective longitudinal data from over 14,000 youth residing in 28 communities in the rural United States were analyzed to examine the emergence of mixed-sex friendship groups in early adolescence. Youth were surveyed on 5 occasions between fall of 6th grade and spring of 9th grade. At each assessment, youth reported the names of up to 7…

In a sample of 711 ethnically diverse adolescents, the observed interpersonal dynamics of dyadic adolescent friendship interactions were coded to predict early adulthood tobacco, alcohol, and marijuana use. Deviant discussion content within the interactions was coded along with dyadic coregulation (i.e., interpersonal coordination, attention…

Many social interactions require the synchronization--be it automatically or intentionally--of one's own behavior with that of others. Using a dyadic drumming paradigm, the authors delineate lifespan differences in interpersonal action synchronization (IAS). Younger children, older children, younger adults, and older adults in same- and mixed-age…

We studied developmental trends in 5 important reasoning tasks that are critical components of the operational definition of rational thinking. The tasks measured denominator neglect, belief bias, base rate sensitivity, resistance to framing, and the tendency toward otherside thinking. In addition to age, we examined 2 other individual difference…