This longitudinal study - conducted in the Midwestern United States - examines the child-level factors that promote Spanish-English bilingual toddlers' (n = 47; M[subscript age] = 18.80 months; SD[subscript age] = 0.57) productive vocabulary skills from 18 to 30 months of age. At 6-month intervals, caregivers reported on toddlers' Spanish and…

Friends are a vital source of social relations throughout the lifespan and across developmental stages. Our knowledge of how friendships develop over time, especially from childhood through adulthood, is limited. Furthermore, it is now recognized that this specific type of relationship influences health across the life course in unique ways. Using…

A foundational mechanism underlying human cooperation is reciprocity. In the context of repeated interactions with others, it is not always clear the degree to which in-kind responses reflect responsiveness to partners' prior behaviors ("reactive" responses), an interest unrelated to the partner ("nonreactive" responses), or…

This study examined parental romantic attachment security as a mediator of prospective associations between hostile interparental conflict and parental discipline (i.e., power-assertive, permissive, and inductive discipline) for mothers and fathers of young children. Furthermore, this study utilized a novel, automatic assessment of romantic…

Children show less positivity toward gender-nonconforming (GN) than gender-conforming (GC) peers. Yet, little is known about children's reasoning about peers of varying gender expressions, including age-, gender-, and culture-related influences. We investigated how children aged 4- to 5- and 8- to 9-years-old in Hong Kong and Canada (N = 678)…

Theory and research highlight the mismatch between puberty-associated challenges and personal coping resources among youth with early actual or perceived pubertal timing. This study (N = 167; M[subscript age] = 12.41 years; 51.5% female; 77.8% White American) examined whether coping resources provided by mothers (maternal socialization of coping)…

Self- and group orientations represent distinct ways of perceiving the relations between the world and the self and are relevant to adolescents' development. Most of the existing studies in this area are cross-sectional, providing little information about how self- and group orientations develop. This 3-year longitudinal study examined the…

Data from 83,423 parent reports of temperament (surgency, negative affectivity, and regulatory capacity) in infants, toddlers, and children from 341 samples gathered in 59 countries were used to investigate the relations among culture, gender, and temperament. Between-nation differences in temperament were larger than those obtained in similar…

Drawing on the situated expectancy-value, dimensional comparison theories, and the intersectionality approach, this article examined the changes in adolescents' math and science motivational beliefs, the parental and college correlates of those beliefs, and the differences at the intersection of gender and college generation status (i.e., female…

Both parasympathetic nervous system regulation and receipt of social support from close relationships contribute to prosocial development, although few studies have examined their combined influences in adolescence and particularly within racially and ethnically minoritized populations. In this longitudinal study of 229 U.S. Mexican-origin…

The heterogeneity in the developmental trajectories of math motivational beliefs (i.e., expectancies for success and subjective task value beliefs) was examined among Asian and Latinx male and female students from Southern California across Grades 8 through 10 (n = 2,710; 50% female; 85% Latinx; 15% Asian; M[subscript age] = 13.77). By conducting…

Perceived control is an important psychosocial resource for health and well-being across the lifespan. Global control (i.e., overall perceived control) decreases over time in studies following people every few years to upwards of 10 years. Changes across wider intervals of the lifespan, however, have yet to be examined. Further, how perceived…

Children and adolescents benefit from positive intergroup peer interactions, but they are unlikely to have many opportunities for these interactions if their parents are uncomfortable with them. Drawing primarily on social identity theory (SIT), this study investigated how U.S. parents' (N = 569) comfort with their children's potential intergroup…

Developmental science suggests that the consequences of mental health problems for life-course outcomes may depend on the timing of their onset. This study investigated the extent to which mental health predicted educational attainment at ages 17, 20, and 25 and whether gender moderated the links between mental health and educational attainment.…

Increasing evidence suggests that success in science, technology, engineering, and math (STEM) fields is not only dependent upon one's actual STEM-relevant abilities but also upon one's STEM-relevant attitudes--in particular, math and spatial attitudes. Here, we examine whether simply mentioning the math or spatial relevance of a task affects…