Throughout adolescence, both sleep and emotion regulation abilities undergo significant developmental changes. The maturational systems that govern sleep and emotion regulation are closely intertwined leading many researchers to posit a mutually reinforcing relationship. Although there is support for a bidirectional relationship among adults,…

This study examined the development of caregiver mind-mindedness--defined as the propensity to see one's child as an agent with an independent mind--across the first 1,000 days of life. At four timepoints (i.e., third trimester of pregnancy, 4, 14, and 24 months postpartum), 384 first-time mothers (M[subscript age] = 32.55, SD = 3.63 years) and…

Very few studies have assessed infant capacity for bidirectional, contingent communication at birth, and to our knowledge there are none with preterm infants in the neonatal period. Presence versus absence of such interactive contingency makes a difference for our theories of development. We examined whether preterm infants can contingently…

Victimization during school years can have detrimental effects on individuals' adjustment, lasting even into adulthood. In the current study, we examine whether there is an indirect effect of victimization on adult depression and aggression, via sad and angry rumination about past victimization. Participants included 1,319 Finnish individuals…

The COVID-19 pandemic is placing demands on parents that may amplify the risk of parents' distress and poor parenting. Leveraging a prepandemic study in New Zealand, the current research tested whether parents' psychological distress during a mandated lockdown predicts relative residual changes in poorer parenting and whether partner support and…

The current study examined the interaction between maternal depressive symptoms and child temperament in predicting subsequent child language skills. Participants were 252 mother-child dyads recruited from the All Our Families longitudinal cohort, a primarily middle-class sample (62.9% completed postsecondary education) from Alberta, Canada (90.5%…

This study examined how family context at age 18 (parent-adolescent conflict, parental support, parent education) predicted between-person variation in subjective well-being (SWB; depressive symptoms and self-esteem) trajectories from age 18 to 50 years. Timing of leaving home, getting married, and becoming a parent were explored as life…

Six waves of data from 944 Canadian high school seniors surveyed for 25 years (age 18 to 43) were analyzed to compare three models of the temporal associations between expressed anger and depressive symptoms (anger [right arrow] depression; depression [right arrow] anger; anger [left right arrow] depression) and a between-persons differences only…

One key objective of life span research is to examine how individual development is shaped by the historical time people live in. Secular trends favoring later-born cohorts on fluid cognitive abilities have been widely documented, but findings are mixed for well-being. It remains an open question whether secular increases in well-being seen in…

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…

Research has documented various family and individual risk factors associated with severe conduct problems, but little is known about the developmental origins of children who engage in both aggressive and prosocial interactions with others. The present study utilized growth-mixture modeling to identify distinct trajectories of physical aggression…

This longitudinal study of midage women has two main aims: to examine the effect of disordered eating (DE) on quality of life (QoL) among women, including a comparison with a younger cohort and to investigate the mediating roles of both depressive symptoms and social support on the longitudinal relationship between DE and QoL as potential…

Developmental processes are inherently time-related, with various time metrics and transition points being used to proxy how change is organized with respect to the theoretically underlying mechanisms. Using data from 4 Swedish studies of individuals aged 70-100+ (N = 453) who were measured every 2 years for up to 5 waves, we tested whether…

Links between social relationships and emotional well-being in old age are well documented, but little is known about daily life fluctuations in momentary affective experiences of the oldest-old while interacting with specific social partners. We examined associations between the presence of different types of social partners and moment-to-moment…

Children who are iron deficient (ID) or iron-deficient anemic (IDA) have been shown to seek and receive less stimulation from their caregivers, contributing to "functional isolation". Over time, the reduced interactions between child and caregiver are thought to interfere with the acquisition of normative social competencies and…