Frequent social interactions are strongly linked to positive affect, longevity, and good health. Although there has been extensive research on changes in the size of social networks over time, little attention has been given to the development of contact frequency across the life span. In this cohort-sequential longitudinal study, we examined…

Cognitive performance is characterized by at least two distinct life course trajectories. Many cognitive abilities (e.g., "effortful processing" abilities, including fluid reasoning and processing speed) improve throughout early adolescence and start declining in early adulthood, whereas other abilities (e.g., "crystallized"…

This study investigates whether individual differences in attachment status can be detected by electrophysiological responses to loss-themed pictures. The Adult Attachment Interview (AAI) was used to identify discourse/reasoning lapses during the discussion of loss experiences via death that place speakers in the Unresolved/disorganized AAI…

Given the sharp increase in rates of depression during adolescence, especially in girls, it is important to identify which youth are at greatest risk across this critical developmental transition. During the present research, we examined whether (a) individual differences in cognition-emotion interaction, as reflected in cognitive control (CC)…

This investigation examines the spread of problem behaviors (substance use and delinquency) between twin siblings. A sample of 628 twins (151 male twin pairs and 163 female twin pairs) drawn from the Quebec Newborn Twin Study completed inventories describing delinquency and substance use at ages 13, 14, and 15. A 3-wave longitudinal actor-partner…

Common sense suggests that romantic partners tend to be interdependent in their well-being and self-esteem. The authors tested the degree to which codevelopment in romantic partners (i.e., development in similar directions) is due to mutual influence between partners or due to the effects of shared environment, using longitudinal data from 5…

Preschool children's use of decontextualized language, or talk about abstract topics beyond the here-and-now, is predictive of their kindergarten readiness and is associated with the frequency of parents' own use of decontextualized language. Does a brief, parent-focused intervention conveying the importance of decontextualized language cause…

Expectations about alcohol's effects and perceptions of peers' behaviors and beliefs related to alcohol use are each shown to strongly influence the timing of drinking onset during adolescence. The present study builds on prior work by examining the conjoint effects of within-person changes in these social-cognitive factors on age of adolescent…

Drawing on the framework of social domain theory, this multi-method, multi-informant longitudinal study examined whether callous-unemotional (CU) tendencies moderated the association between U.S. 4 to 7 year olds' (n = 135; M[subscript age] = 5.65, 50% male; 75% White) ability to differentiate hypothetical, prototypical moral and conventional…

Although Erikson (1968) originally conceptualized identity development as a process of becoming at home in one's body, little work has been done linking identity development and research on the body. This study examines how trajectories of the development of body esteem over time are related to young people's sense of identity and psychological…

Both environmental factors and genetic variation, particularly in genes responsible for the dopaminergic system such as "DRD4," "DRD2," and "DAT1" ("SLC6A3"), affect adolescent delinquency. The school context, despite its developmental importance, has been overlooked in gene-environment research. Using data…

The developmental trajectories of selective and divided attention were examined in relation to the processing of hierarchically integrated stimuli. The participants included children in 4 age groups (6, 8, 10, and 12 years) and a group of young adults (24 years) who completed 2 computer-based attention tasks. In the selective attention task, the…

Infants' motor skill development triggers changes in parent-infant interactions, exploration, and play behaviors, particularly during periods of locomotor transitions. We investigated how these transitions reorganized infants' and mothers' explorations of spatial layouts. Thirteen infants and their mothers were followed biweekly from the age of 6…

The present study explored how romantic relationship qualities develop with age and relationship length. Eight waves of data on romantic relationships were collected over 10.5 years during adolescence and early adulthood from a community-based sample in a Western U.S. city (100 males, 100 females; M age Wave 1 = 15.83). Measures of support,…

We apply a biopsychosocial conceptualization to attention development in the 1st year and examine the role of neurophysiological and social processes on the development of early attention processes. We tested whether maternal behavior measured during 2 mother-child interaction tasks when infants (N = 388) were 5 months predicted infant medial…