This preregistered, longitudinal study examined how much adolescents value and integrate their parents' and peers' attitudes into their own attitudes from early to middle adolescence. Across three waves, participants (N = 172, 91 female, 11-16 years across three waves; 439 data points) decided whether to pay money to learn their parents' or peers'…

Infant motor development is affected by the sociocultural context in which it takes place. Because societal and cultural practices are dynamic, this exploratory study examined whether the ages at which infants typically learned to crawl, cruise, and walk changed over the past 3 decades. We compiled archival data from 1,306 infants born between…

Neighborhood is a key context where children learn to process social information; however, the field has largely overlooked the ways children's individual characteristics might be moderated by neighborhood effects. We examined 1,030 six- to 11-year-olds (48.7% female; 82% White) twin pairs oversampled for neighborhood disadvantage from the Twin…

Prior theoretical and empirical research has highlighted links between positive parenting and the socioeconomic characteristics of the family's neighborhood, but has yet to illuminate the etiologic origins of this association. One possibility is that the various predictors of parenting outlined by Belsky (1984; e.g., characteristics of the child,…

The aim of the study was to examine associations between life events and self-assessed loneliness in adolescence. We used data from a Norwegian population-based twin sample including seven birth cohorts (N = 2,879, 56% females). The participants completed self-report questionnaires three times throughout adolescence, with 2 years in between (i.e.,…

Previous research on parent-led race conversations reports robust racial differences in the content of race conversations between Black and white parents. It was unknown, however, whether these racial differences shifted in the months immediately following the summer of 2020 when there was heightened public attention directed toward white parents,…

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…

Adolescence is a critical developmental period that is marked by drastic changes in face recognition, which are reflected in patterns of bias (i.e., superior recognition for some individuals compared to others). Here, we evaluate how race is perceived during face recognition and whether adolescents exhibit an own-race bias (ORB). We conducted a…

While there is considerable evidence that children's early ability to understand others' mental states, called "theory of mind," is shaped by family experiences, it remains unclear whether children's social interactions at school influence theory of mind (ToM) beyond early childhood. We tested whether the mean level…

Although parent-child conversations about race are recommended to curb White U.S. children's racial biases, little work has tested their influence. We designed a guided racism discussion task for U.S. White parents and their 8-12-year-old White children. We explored whether children's and parents' (a) pro-White implicit biases changed pre to…

This study examines the moment-to-moment within-person associations between maternal and child behaviors during a challenging puzzle task and compares these associations between mother--child dyads from the United States (n = 99, 52 boys, M[subscript child age] = 56.05 months, SD = 6.44) and China (n = 101, 46 boys, M[subscript child age] = 57.41…

Independent locomotion is associated with a range of positive developmental outcomes, but unlike cognitive, linguistic, and social skills, acquiring motor skills requires infants to generate their own input for learning. We tested factors that shape infants' spontaneous locomotion by observing forty 12- to 22-month-olds (19 girls, 21 boys) during…

The number of U.S. children living in households with extended families has greatly increased in the last 4 decades. This demographic shift calls for a reevaluation of the impact of household size on children's development. Household density (HHD), measured as the ratio of people to bedrooms in a home, has been shown to negatively relate to…

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…

Sometime before their second birthday, many children have a period of rapid expressive vocabulary growth called the vocabulary spurt. Theories of the underlying mechanisms differ: Accumulator models emphasize the accumulation of experience with words over time to yield a spurtlike pattern, while cognitive models attribute the spurt to cognitive…