Executive function and theory of mind as predictors of aggressive and prosocial behavior and peer acceptance in early childhood

An information-processing model is outlined that predicts that performance on non-routine tasks can be impaired independently of performance on routine tasks. The model is related to views on frontal lobe functions, particularly those of Luria. Two methods of obtaining more rigorous tests of the model are discussed. One makes use of ideas from artificial intelligence to derive a task heavily loaded on planning abilities. A group of patients with left anterior lesions has a specific deficit on the task. Subsidiary investigations support the inference that this is a planning impairment.

This meta-analytic review of 148 studies on child and adolescent direct and indirect aggression examined the magnitude of gender differences, intercorrelations between forms, and associations with maladjustment. Results confirmed prior findings of gender differences (favoring boys) in direct aggression and trivial gender differences in indirect aggression. Results also indicated a substantial intercorrelation (r = .76) between these forms. Despite this high intercorrelation, the 2 forms showed unique associations with maladjustment: Direct aggression is more strongly related to externalizing problems, poor peer relations, and low prosocial behavior, and indirect aggression is related to internalizing problems and higher prosocial behavior. Moderation of these effect sizes by method of assessment, age, gender, and several additional variables were systematically investigated.

Examine age group effects and sex differences by applying a comprehensive computerized battery of identical behavioral measures linked to brain systems in youths that were already genotyped. Such information is needed to incorporate behavioral data as neuropsychological "biomarkers" in large-scale genomic studies. We developed and applied a brief computerized neurocognitive battery that provides measures of performance accuracy and response time for executive-control, episodic memory, complex cognition, social cognition, and sensorimotor speed domains. We tested a population-based sample of 3,500 genotyped youths ages 8-21 years. Substantial improvement with age occurred for both accuracy and speed, but the rates varied by domain. The most pronounced improvement was noted in executive control functions, specifically attention, and in motor speed, with some effect sizes exceeding 1.8 standard deviation units. The least pronounced age group effect was in memory, where only face memory showed a large effect size on improved accuracy. Sex differences had much smaller effect sizes but were evident, with females outperforming males on attention, word and face memory, reasoning speed, and all social cognition tests and males outperforming females in spatial processing and sensorimotor and motor speed. These sex differences in most domains were seen already at the youngest age groups, and age group × sex interactions indicated divergence at the oldest groups with females becoming faster but less accurate than males. The results indicate that cognitive performance improves substantially in this age span, with large effect sizes that differ by domain. The more pronounced improvement for executive and reasoning domains than for memory suggests that memory capacities have reached their apex before age 8. Performance was sexually modulated and most sex differences were apparent by early adolescence.