Current prediction instruments for violent recidivism lack accuracy as recidivism rates for violent offenses remain high (Fazel & Wolf, 2015). Part of the issue may be the conceptualization of violent offenders as a homogenous group as opposed to heterogeneous subgroups. Additionally, various studies suggest that cognitive abilities in violent offenders warrant further exploration as cognitive deficits have been associated with antisocial behavior (Brower & Price, 2001; Golden, Jackson, Peterson-Rohne, & Gontkovsky, 1996; Moffitt, 1990; Morgan & Lilienfeld, 2000; Raine, 2013; Syverson & Romney, 1985). However, research on cognition in violent offender subgroups is lacking. The current work addresses this gap with three manuscripts that establish cognitive profiles for subgroups of violent offenders and investigate whether these subgroups differ on descriptive characteristics or cognitive abilities. The first study compares descriptive characteristics and cognitive abilities of mass murderers to single victim murderers using independent t-tests or Wilcoxon Rank-Sum tests for continuous variables and chi-square tests or Fisher’s exact test for categorical variables. The second study compares descriptive characteristics and cognitive abilities of female to male homicide offenders using independent t-tests or Wilcoxon Rank-Sum tests for continuous variables and chi-square tests or Fisher’s exact test for categorical variables. The third study uses classification and regression tree (CART) analysis to determine combinations of factors that best discriminate IPV perpetrators from other violent offenders. Additionally, it compares cognitive performance between IPV perpetrators and other violent offenders with independent t-tests or Wilcoxon Rank-Sum tests. Results suggest that most subgroups of violent offenders do not exhibit cognitive impairment in comparison to test normative data. However, violent subgroups differ on descriptive characteristics and/or cognition. Specifically, mass murderers are more likely to commit a premeditated crime and have better language, processing speed, reasoning, and verbal memory abilities than single victim murderers. Female homicide offenders demonstrate different types of personality disorders, elevated prevalence of mood disorders, greater history of abuse, lower rates of substance abuse, and poorer verbal memory performance than male homicide offenders. While IPV offenders do not differ from other violent offenders on cognitive performance, CART analysis indicates that certain combinations of variables distinguish IPV perpetrators from other violent offenders with high accuracy. Specifically, IPV perpetrators can be identified by three pathways: 1) extensive nonviolent criminal history, 2) interpersonal traits of psychopathy without attentional difficulties, or 3) neurodevelopmental diagnosis without interpersonal psychopathic traits. Overall, findings provide preliminary evidence for distinct criminological factors in various subgroups of violent offenders. Specifically, cognition and life history variables of psychopathy, premeditation, psychiatric history, and abuse history differ among violent subgroups. These differences indicate a need to conceptualize and examine violent offenders as distinct subgroups as opposed to a homogenous group.

Creator

• Fox, Jaclyn Michelle

DOI

• https://doi.org/10.21985/n2-gv8r-g924

Subject

• Clinical psychology

Language

• en

Alternate Identifier

• http://dissertations.umi.com/northwestern:15194
• etdadmin_upload_756237

Keyword

• Homicide
• Forensic Neuropsychology
• Premeditation
• Psychopathy
• Violence
• Cognition

Date created

• 2018-01-01

Resource type

• Dissertation

Rights statement

• In Copyright