The second year of life is a time of formative developmental change as basic behavioral systems undergo rapid integration and expansion. This study examined the developmental trajectories of social-emotional (SoE) outcomes and the effects of infant sex and household chaos (HC) on the development of SoE outcomes across the second year of life. The…

Despite ample research on empathy development, its social origins have been understudied, particularly in the context of peer relations. This two-wave study of Swedish adolescents (N = 318; M[subscript ageT1] = 16.28, SD = 0.49; 55% females) examined longitudinal associations between youth friendships and empathy. The results showed that…

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…

Past meta-analyses show that both child-mother and child-father attachment insecurity are independently and jointly associated with more externalizing behaviors in children. Little is known, however, on the ways that different types of insecure attachment independently and jointly predict the development of externalizing behaviors over time.…

We investigated the longitudinal associations among maternal pre- and postnatal depression, maternal anxiety, and children's language and cognitive development followed from 15 to 61 months. Furthermore, we assessed the protective role of children's early print experiences with books against the adverse effect of maternal depression on language…

This study quantified changes in self-reported sexual orientation from adolescence to early adulthood, and whether childhood gender nonconformity (GNC) predicted sexual orientation changes. Youth (2,678 boys and 3,359 girls; 96.09% ethnically White) from the Avon Longitudinal Study of Parents and Children (ALSPAC) were included. Self-reported…

Existing research focused on social role destabilization (historical increases in role instability) and destandardization (historical increases in variability of role instability) has primarily focused on discrete social roles during discrete periods of development. Building on this work, we applied a macro approach to elucidate the extent to…

Between 6 and 9 years of age, children's free associations shift from syntagmatic to paradigmatic relationships. "Syntagmatic relations" are words that are syntactically adjacent, thematically related ("summer-vacation"), or both; "paradigmatic relations" are words from the same grammatical class, taxonomic category…

Adolescence and emerging adulthood is likely a sensitive period for the neural effects of stress due to increasing life stress, onset of stress-related disorders, and continued gray matter (GM) development. In adults, stress is associated with GM differences in the medial prefrontal cortex (mPFC), hippocampus, and amygdala, but little is known…

Intrusive parenting has been traditionally considered a negative parenting style and includes actions that are overly directive and controlling of children's behavior. However, current research aims to contextualize this parenting behavior. This study examined the relation between intrusive parenting and early childhood behavior problems or…

We leveraged nationally representative data from the Panel study of Income Dynamics-Child Development Supplement (N = 3,562) and the Early Childhood Longitudinal study (N = 18,174), to chart the development of working memory, indexed via verbal forward and backward digit span task performance, from 3 to 19 years of age. Results revealed nonlinear…

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…

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…

Increasing research shows pubertal development accelerates following threats while it decelerates following deprivation. Yet, these environmental stressors are unlikely to occur in isolation. We investigated how war exposure and energetic stress impact pubertal development using data from the longitudinal Biological Pathways of Risk and Resilience…

Adolescence is a critical period for social development, which COVID-19 has dramatically altered. Quarantined youths had limited in-person interactions with peers. The present study used an intensive longitudinal design to investigate changes in interpersonal dynamics and mental health during COVID-19. Specifically, we investigated whether the…