Children's hypothetical reasoning about a complex and dynamic causal system was investigated. Predominantly White, middle-class 5- to 7-year-old children from the Greater Toronto Area learned about novel food chains and were asked to consider the effects of removing one species on the others. In Study 1 (N = 72; 36 females, 36 males; 2018),…

Trajectories of cognitive and neural development suggest that, despite early emergence, the ability to extract environmental patterns changes across childhood. Here, 5- to 9-year-olds and adults (N = 211, 110 females, in a large Canadian city) completed a memory test assessing what they remembered after watching a stream of shape triplets: the…

This study examined bidirectional associations between cross-racial friendships and children's social and academic adjustment. Participants were 583 elementary school-age children in western Canada, or the midwestern United States (4-10 years; 279 girls; 143 Asian, 88 Black, 65 Hispanic or Latinx, 171 White, 116 mixed). Children's adjustment…

This study examined judgments and reasoning about four parental discipline practices (induction or reasoning and three practices involving "psychological control"; Barber, 1996; two forms of shaming and love withdrawal) among children (7-14 years of age) from urban and rural China and Canada (N = 288) in response to a moral…

This study examined the associations between intrinsic motivation and achievement in mathematics in a sample of 1,478 Canadian school-age children followed from Grades 1 to 4 (ages 7-10). Children self-reported their intrinsic motivation toward mathematics, whereas achievement was measured through direct assessment of mathematics abilities.…

Two experiments investigated response tendencies of preschoolers toward yes-no questions about actions. Two hundred 2- to 5-year-old children were asked questions concerning actions commonly associated with particular objects (e.g., drinking from a cup) and actions not commonly associated with particular objects (e.g., kicking a toothbrush). The…

This study examined the contribution of nonparental child-care services received during the preschool years to the development of social behavior between kindergarten and the end of elementary school with a birth cohort from Québec, Canada (N = 1,544). Mothers reported on the use of child-care services, while elementary school teachers rated…

This study assessed the genetic and environmental contributions to peer difficulties in the early school years. Twins' peer difficulties were assessed longitudinally in kindergarten (796 twins, "M"[subscript age] = 6.1 years), Grade 1 (948 twins, "M"[subscript age] = 7.1 years), and Grade 4 (868 twins, "M"[subscript…

Recollection of early childhood experiences was investigated in 225 European Canadian and 133 Chinese children (ages 8, 11, and 14) by a memory fluency task that measured accessibility of multiple early memories and elicited the earliest memory. Younger children provided memories of events that occurred at earlier ages than older children.…

This study examined how the link between neighborhood poverty and the timing of sexual initiation varies as a function of age, gender, and background characteristics. A sample of N = 2,596 predominately White Canadian adolescents from the National Longitudinal Survey of Children and Youth was used. Sexual initiations occurring between 12 and 15…

Children as young as eight years of age can discriminate between affect-eliciting statements, differentially rate up to five concurrent emotional responses, and predict response patterns similar to those predicted by adults. During adolescence, there are sex differences in the prediction of secondary emotions. (RH)

Thirty-four pairs of same-sex siblings were observed for two one-hour periods in their homes. The younger siblings averaged 20 months of age and the age interval between siblings was either large (2.5-4 years) or small (1-2 years). (JMB)

Using a genetic design of 840 60-month-old twins, this study investigated the genetic and environmental contributions to (a) individual differences in four components of cognitive school readiness, (b) the general ability underlying these four components, and (c) the predictive association between school readiness and school achievement. Results…

Systematic observations of affiliative interaction in 15 stable peer groups were conducted across three years in an urban day care center. Groups contained 193 French-speaking children ranging in age from one to six years. (Author/RH)

In a longitudinal study of sibling interaction, same-sex and mixed-sex pairs of siblings were observed twice in their homes. Interaction patterns remained stable over the 18 months separating the two observations. Older children initiated prosocial and combative behavior more often than younger children and submitted less often to dominant…