The purpose of this study was to investigate the longitudinal prevalence of relative age effects (RAEs) across playing levels and positions in Northern Ireland international male soccer. Birthdates of U17 (n = 276), U19 (n = 320), U21 (n = 331), and senior (n = 108) international players between 2011 and 2023 were recorded. Chi-square tests and…

Self-injurious and aggressive behaviors are common in fragile X syndrome (FXS). However, little is known about the persistence of these behaviors and associated risk markers. We established the prevalence and persistence of self-injurious and aggressive behaviors over eight years in males with FXS, and associations with risk markers. Results…

Since the onset of the Great Recession over six years ago, restoring full employment has been the most urgent labor market priority. As the economy slowly recovers, long-term labor market challenges will receive renewed attention. Among the most significant is the growing earnings divide between different types of workers and the potential role of…

One of the most consistent findings in developmental criminology is the "age-crime curve"--the observation that criminal behavior increases in adolescence and decreases in adulthood. Recently, Brown and Males (Justice Policy J 8:1-30, 2011) conducted an analysis of aggregate arrest, poverty, and population data from California and…

The perpetration of bullying is a significant issue among researchers, policymakers, and the general public. Although researchers have examined the link between bullying and subsequent antisocial behavior, data and methodological limitations have hampered firm conclusions. This study uses longitudinal data from 411 males in the Cambridge Study in…

Using prospective, longitudinal data spanning 10 years (age = 10-20) from a study of 295 economically disadvantaged males, the current investigation evaluated a developmental model that links early family environment and later educational aspirations, extracurricular activities, and educational attainment to substance use in early adulthood. The…

This paper draws on the story of "Mikael", a schoolboy from northern Finland, to examine how his affective ties of compassion and his pursuit of dominant forms of masculinity evolve in his journey from middle childhood to young adulthood. In his earlier years, Mikael's speech regarding his relationships with peers and family members…

It is important to account for timing of puberty when studying the adolescent brain and cognition. The use of classical methods for assessing pubertal status may not be feasible in some studies, especially in male adolescents. Using data from a sample of 478 males from a longitudinal birth cohort, we describe the calculations of three independent…

Infants and their mothers participated in a longitudinal study of the sequelae of infant goal-blockage responses. Four-month-old infants participated in a standard contingency learning and goal-blockage procedure during which anger and sad facial expressions to the blockage were coded. When infants were 12 and 20 months old, mothers completed a…

A meta-analysis of 187 studies containing 247 independent studies (N = 68,429) on gender differences in academic self-efficacy identified an overall effect size of 0.08, with a small difference favoring males. Moderator analysis demonstrated that content domain was a significant moderator in explaining effect size variation. Females displayed…

This longitudinal study examined the direction of effects between adolescents' generalized anxiety disorder (GAD) symptoms and perceived parent-adolescent attachment relationship quality, as well as the moderating role of gender and age. 1,313 Dutch adolescents (48.5% boys) from two age cohorts of early (n = 923, M[subscript age] = 12 at W1) and…

Objectives: To investigate whether smoking prevalence in grade-level networks influences individual smoking, suggesting that peers are important social multipliers in teen smoking. Methods: We measured gender-specific, grade-level recent and life-time smoking among urban middle-school students who participated in Project Northland Chicago in a…

Background: Preliminary evidence suggests that prenatal testosterone exposure may be associated with language delay. However, no study has examined a large sample of children at multiple time-points. Methods: Umbilical cord blood samples were obtained at 861 births and analysed for bioavailable testosterone (BioT) concentrations. When…

Objective: This article first summarizes key research findings from the Pittsburgh Youth Study from 1987 to the present, and focuses on delinquency in 1,517 young men who have been followed up from late childhood into their 20s. Second, the article addresses how indicators of self-control prospectively predict later offending, and whether the…

This study examined reciprocal relationships between adolescents' perceptions of parental nurturance and two types of adolescent aggressive behaviors (indirect and direct aggression) using a transactional model. Three waves of longitudinal data were drawn from the Canadian National Longitudinal Survey of Children and Youth. The sample included…