Wednesday, March 26, 2014, at 4:00 pm
Room 200, Graduate Student Center
Title: Executive Functions and Subtypes of Childhood Aggression
Co-Supervisors: Dr. Laurie Ford & Dr. Shelley Hymel (ECPS)
Supervisory Committee: Dr. Adele Diamond (Psychiatry)
University Examiners: Dr. Nancy Perry (ECPS) & Dr. Amori Mikami (Psychology)
External Examiner: Dr. Jamie Ostrov, University of Buffalo, State University of New York
ABSTRACT
In the present study, linkages between early aggression and Executive Functions (EFs), the cognitive control processes associated with goal-directed behavior and novel problem solving, were evaluated. Of interest was how specific EFs were related to early dimensional subtypes of aggression, specifically disaggregated into its forms (overt, relational) and functions (proactive, reactive). A sample of 255 Kindergarten children was individually rated by teachers in terms of their tendencies to engage in four different subtypes of aggression — proactive and reactive physical aggression, and proactive and reactive relational aggression. Children identified as high versus low in each of the four subtypes of aggression were compared in terms of differences in “cool EFs,” such as executive attention, inhibition, working memory, flexibility, planning, and the conjoint use of several EFs, and “hot EF” or more affectively-based cognitive control.
Results of a series of 2 (high, low aggression) by 2 (male, female) analyses of variance, conducted for each of the four subtypes of aggression, indicated significant differences in executive functioning as a function of both levels of aggression and sex (main effects), with few interactions of sex and aggression. Males were rated by their teachers as displaying higher levels of proactive and reactive physical aggression, and also more attention problems than females, whereas no significant sex differences in proactive or reactive relational aggression were observed. Differential patterns of EFs were observed across aggression subtypes and for male versus female children. Higher levels of proactive physical aggression were associated with weaknesses in several specific EFs (i.e., more attention problems, lower visual working memory, conjoint attention, shifting and working memory, and delay of gratification), as were higher levels of reactive physical aggression (i.e., more attention problems, poorer inhibition, visual working memory, flexibility, and conjoint attention, shifting and working memory). Boys with reactive physical aggression demonstrated additional EF impairments, including lower delay of gratification and marginally lower planning abilities. Further, girls high in proactive relational aggression demonstrated stronger verbal working memory and planning abilities, and marginally higher verbal abilities, whereas boys high in reactive relational aggression demonstrated poor planning abilities, and marginally poorer visual working memory abilities.