Findings from previous cross-sectional studies showed that while toddlers around their first birthday imitate selectively, that is, they systematically omit some kinds of target action steps or they copy only the goal, but not the means of the modeled actions, older toddlers imitate more exactly. The aim of the present article is to provide…

In the present investigation, we studied the development of 6 physically aggressive behaviors in infancy and toddlerhood, posing 3 questions (a) How do the prevalences of individual physically aggressive behaviors change from 8, 15, and 24 months? (b) Are there groups of children who show distinctive patterns in the way individual physically…

The purpose of this study was to examine time-varying associations of parent-adolescent cultural conflict with depressive symptoms and grade point average (GPA) among Chinese Americans from ages 11-22. We pooled two independently collected longitudinal data sets (N = 760 at Wave 1) and used time-varying effect modeling (TVEM) to show that the…

We examined children's sleep at age 9 as a predictor of developmental trajectories of cognitive performance from ages 9 to 11 years. The effects of sleep on cognition are not uniform and thus we tested race/ethnicity, socioeconomic status (SES), and sex as moderators of these associations. At the first assessment, 282 children aged 9.44 years (52%…

Identity formation in adolescence is closely linked to searching for and acquiring meaning in one's life. To date little is known about the manner in which these 2 constructs may be related in this developmental stage. In order to shed more light on their longitudinal links, we conducted a 3-wave longitudinal study, investigating how identity…

This study focuses on the development of the understanding of historical time of pupils in primary school. We present a developmental model with three stages: "emergent," "initial" and "continued" understanding of historical time. Based on this model, we constructed an instrument to measure how pupils aged 6-12…

Bullying in schools is an international problem impacting negatively on children's well-being. Children's drawings can provide an insight into their emotional states. There is little published literature that uses children's drawings to gain better understandings of the nature and impact of bullying. We report two studies using indicators of…

Purpose: We aimed to provide novel information on utterance duration as it relates to vocal type, facial affect, gaze direction, and age in the prelinguistic/early linguistic infant. Method: Infant utterances were analyzed from longitudinal recordings of 15 infants at 8, 10, 12, 14, and 16 months of age. Utterance durations were measured and coded…

Background: Intra-individual variability reflects temporal variation within an individual's performance on a cognitive task. Children with developmental disorders, such as ADHD and ASD show increased levels of intra-individual variability. In typical development, intra-individual variability decreases sharply between the ages 6 and 20. The tight…

Consistently with a priori predictions, school retention (repeating a year in school) had largely positive effects for a diverse range of 10 outcomes (e.g., math self-concept, self-efficacy, anxiety, relations with teachers, parents and peers, school grades, and standardized achievement test scores). The design, based on a large, representative…

For decades, scholars have examined how children first recognize emotional facial expressions. This research has found that infants younger than 10 months can discriminate negative, within-valence facial expressions in looking time tasks, and children older than 24 months struggle to categorize these expressions in labeling and free-sort tasks.…

This study examines historical variation in age 18 to 26 binge drinking trajectories, focusing on differences in both levels of use and rates of change (growth) across cohorts of young adults over 3 decades. As part of the national Monitoring the Future Study, over 64,000 youths from the high school classes of 1976 to 2004 were surveyed at…

This three-year follow-up study investigated the associations of narrative and reading skills in typically developing Finnish children. Twenty children performed narrative retelling and story generation tasks twice, at five and eight years of age. Reading comprehension and word recognition tests were performed at the age of eight. Narratives were…

This study examined pubertal maturation, pubertal timing and outcomes, and the relationship of puberty and sexual identity developmental milestones among 507 lesbian, gay, and bisexual youth. The onset of menarche and spermarche occurred at the mean ages of 12.05 and 12.46, respectively. There was no statistically significant difference in…

One way to avert negative influences on well-being when confronted with blocked goals is the flexible adjustment of one's goals to the given situation. This study examines developmental differences in flexible goal adjustment (FGA) regarding age and gender in a sample of N = 815 participants (10 to 20 years; M = 13.63, SD = 2.60, 48.5% male).…