Date of Award


Publication Type

Doctoral Thesis

Degree Name




First Advisor

Menna, Rosanne (Psychology)






ABSTRACT In light of recent findings suggesting that physical aggression peaks during the toddler years then declines steadily beginning in preschool (e.g., Alink et al., 2006; Tremblay et al., 2004), greater emphasis has been placed on identifying early factors that might predispose children to disruptive behaviour problems as they mature. The present study investigated the effects of early language development, executive functioning, and maternal scaffolding on physically aggressive behaviour among a sample of preschool-aged children (N = 126). In step one, regression analyses revealed various preschooler language abilities negatively predicted physical aggression after controlling for potential confounding variables (e.g., children's IQ, family structure, socioeconomic status, or maternal education). The second set of analyses showed preschoolers' executive functions (i.e., inhibitory self-control, emergent metacognition) mediated the relation between their language abilities and physical aggression. Maternal scaffolding was introduced in the third step of analyses and was found to predict preschoolers' semantic language abilities. After separating the sample on the basis of scaffolding quality, differences were found in terms of the specific executive functions that mediated the language-aggression relation between groups. The results are interpreted from a developmental perspective, with reference to the work of Vygotsky (1962, 1978). The implications of these findings for early intervention of disruptive behaviour problems are also discussed and recommendations are made for future research in the area of selfregulation.