Given the centrality of prosociality in everyday social functioning, understanding the factors and mechanisms underlying the origins of prosocial development is of critical importance. This experiment investigated whether experience with reciprocal object exchanges can drive the developmental onset of sharing behavior. Seven-month-old infants took…

This study tests the hypothesis that adolescents with romantic partners are less similar to their friends on rates of alcohol abuse than adolescents without romantic partners. Participants (662 girls, 574 boys) ranging in age from 12 to 19 years nominated friends and romantic partners, and completed a measure of alcohol abuse. In hierarchical…

We investigated the role of sociocultural (between-groups) and individual (within-group) factors on the development of preschoolers' resource-allocation preferences. We tested claims of the "joint impact hypothesis" of social values development that social-emotional understanding skills would predict the transition from simpler…

The present longitudinal study addressed the ongoing debate regarding the benefits and risks of infant-parent cosleeping by examining associations between sleep arrangement patterns across the first year of life and infant and parent sleep, marital and family functioning, and quality of mothers' behavior with infants at bedtime. Patterns of infant…

Controversy continues to surround parenting by lesbian and gay (LG) adults and outcomes for their children. As sexual minority parents increasingly adopt children, longitudinal research about child development, parenting, and family relationships is crucial for informing such debates. In the psychological literature, family systems theory contends…

This study used data from 356 children, their mothers, teachers, and peers to examine the longitudinal and dynamic associations among 3 dimensions of social competence derived from Hinde's (1987) framework of social complexity: social skills, peer group acceptance, and friendship quality. Direct and indirect associations among each discrete…

A robust finding across research on early childhood educational interventions is that the treatment effect diminishes over time, with children not receiving the intervention eventually catching up to children who did. One popular explanation for fadeout of early mathematics interventions is that elementary school teachers may not teach the kind of…

Reviews of behavioral genetic studies note that "control" aspects of parenting yield low estimates of heritability, while "affective" aspects (parental feelings) yield moderate estimates. Research to date has not specifically considered whether positive and negative aspects of parenting--for both feelings and control--may…

Developmental studies on heuristics and biases have reported controversial findings suggesting that children sometimes reason more logically than do adults. We addressed the controversy by testing the impact of children's knowledge of the heuristic stereotypes that are typically cued in these studies. Five-year-old preschoolers and 8-year-old…

The authors examined siblings' dyadic and differential conflict frequency with mothers and fathers from 7 to 19 years of age. Participants were first- and second-borns from 201 families who reported their conflict with each parent in 4 home interviews spaced over 5 years. Multilevel models examining trajectories of conflict frequency across age…

Longitudinal analysis of 10-year follow-up data on objectified body consciousness, body esteem, weight-related attitudes and behaviors, and psychological well-being in 74 middle-aged and 72 young women tested hypotheses developed from age-related change and cohort differences models of body experience. Young women's body surveillance and body…