The Neglected Offender: Exploring the Role of Executive Dysfunction in Violent Offending

by Crump, Sheree A

Executive dysfunction and aggression and violence have been consistently associated in the research literature over at least the last 50 years. Some literature documents profound behaviour changes and the development of antisocial traits after changes to the prefrontal cortex and it’s supporting neural networks. Other research makes tentative links using brain imaging and neuropsychological methods. Prefrontal dysfunction can lead to executive dysfunction, and executive dysfunction may constitute a pathway to violence. Robust demonstrations of the association between executive function and violence have been limited by poor methodology in previous studies. This study attempts to address methodological concerns and uses a neuropsychological battery to examine the role of the executive functions in the expression of violence through violent offending. It is hypothesised that problems with executive functioning as measured by a neuropsychological battery may be linked to violent offending through impulsivity and disinhibition. Two studies were completed with sixty participants across the two groups. In the first study three groups of men were assessed on tests of executive dysfunction; 21 inmates convicted of violent crimes; 16 inmates convicted of non-violent crimes; and a matched control sample of 16 men in the community who are conviction free. Results demonstrate a positive relationship between executive dysfunction and violent offending. A similar association was demonstrated between the length of formal education each participant across the sample reported, with less years of education increasing the likelihood of participants being in one of the incarcerated groups. The second study examined neuropsychological differences between seven murderers; three who killed impulsively and four who premeditated a murder. There were no conclusive results from this study, which may be due to the small sample size. It is suggested that identifying pathways to violence can inform therapeutic interventions. The indication of executive dysfunction as a pathway to violence was used to develop an intervention specifically geared towards executive deficits in violent offenders. The third study, Study Three (which was not completed due to constraints imposed by the research setting beyond the control of the researcher) includes the design of a study to assess the outcome of an intervention for inmates with ED. The intervention itself is appended to this thesis.