Differences in executive functioning between violent and non-violent offenders.
BACKGROUND
A growing body of neuropsychological and neurobiological research shows a relationship between functioning of the prefrontal cortex and criminal and violent behaviour. The prefrontal cortex is crucial for executive functions such as inhibition, attention, working memory, set-shifting and planning. A deficit in these functions - a prefrontal deficit - may result in antisocial, impulsive or even aggressive behaviour. While several meta-analyses show large effect sizes for the relationship between a prefrontal deficit, executive dysfunction and criminality, there are few studies investigating differences in executive functions between violent and non-violent offenders. Considering the relevance of identifying risk factors for violent offending, the current study explores whether a distinction between violent and non-violent offenders can be made using an extensive neuropsychological test battery.


METHODS
Male remand prisoners (N = 130) in Penitentiary Institution Amsterdam Over-Amstel were administered an extensive neuropsychological test battery (Cambridge Automated Neuropsychological Test Battery; CANTAB) measuring response inhibition, planning, attention, set-shifting, working memory and impulsivity/reward sensitivity.


RESULTS
Violent offenders performed significantly worse on the stop-signal task (partial correlation r = 0.205, p = 0.024), a task measuring response inhibition. No further differences were found between violent and non-violent offenders. Explorative analyses revealed a significant relationship between recidivism and planning (partial correlation r = -0.209, p = 0.016).


CONCLUSIONS
Violent offenders show worse response inhibition compared to non-violent offenders, suggesting a more pronounced prefrontal deficit in violent offenders than in non-violent offenders.
Department of Clinical, Neuro- and Developmental Psychology,Vrije Universiteit Amsterdam,Amsterdam,The Netherlands.
J
J
Meijers
Department of Criminal Law and Criminology,Vrije Universiteit Amsterdam,Amsterdam,The Netherlands.
J M
JM
Harte
Department of Philosophy,Faculty of Humanities,Vrije Universiteit Amsterdam,Amsterdam,The Netherlands.
G
G
Meynen
Department of Clinical, Neuro- and Developmental Psychology,Vrije Universiteit Amsterdam,Amsterdam,The Netherlands.
P
P
Cuijpers
D000328:Adult; D057237:Criminals; D056344:Executive Function / Q000502:physiology*; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D008875:Middle Aged; D017397:Prefrontal Cortex / Q000503:physiopathology*; D011329:Prisoners; D014754:Violence; D055815:Young Adult
CANTAB; executive function; inhibition; neuropsychology; offenders; prison