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Neuropsychological and Intellectual Differences Between Types of Murderers: Affective/Impulsive Versus Predatory/Instrumental (Premeditated) Homicide

NCJ Number
Criminal Justice and Behavior Volume: 40 Issue: 8 Dated: August 2013 Pages: 933-948
Robert E. Hanlon; Michael Brook; John Stratton; Marie Jensen; Leah H. Rubin
Date Published
August 2013
16 pages

This study examined whether offenders who commit proactive versus reactive types of murder are characterized by distinct neurocognitive profiles.


The notion that affective/impulsive violence and predatory/instrumental violence constitute distinct behavioral phenotypes has been supported in the forensic literature. Prior research suggests that offenders committing affective/impulsive homicide exhibit differing patterns of anomalous regional brain activation and decreased executive functions relative to predatory/instrumental homicide offenders. However, no prior research has examined the extent to which murderers who kill impulsively versus those who kill as the result of the execution of a premeditated strategic plan differ with regard to other neuropsychological functions and intelligence. Based on established criteria, the authors classified 77 murderers into affective/impulsive and predatory/instrumental groups, and compared their performance on standardized measures of intelligence and neuropsychological functioning. Results revealed significant differences between the affective/impulsive group (mean Full Scale IQ = 79) and the predatory/instrumental group (mean Full Scale IQ = 93) on indices of intelligence, memory, attention, and executive functioning. Most differences remained significant after controlling for relevant background factors. Abstract published by arrangement with Sage Journals.