Neurological subtypes of violent behaviour: differences in inhibition between affective and instrumental violence

Violent behaviour is a complex problem, not only for the society but also from a scientific perspective. It is not a generic, homogeneous phenomenon, but it is associated with social, psychological and biological determinants that interact and contribute to the violent act.

Auteurs: Thijs W. van de Kant, Swaantje F. Boers, Maaike Kempes en Jos I.M. Egger.

Forensic assessment is primarily focused on psychosocial factors to understand aggressive behaviour. However, evidence suggests a relation between neurocognitive factors and violence. Inhibition is one of those factors possibly related to violent behaviour, but prior research regarding inhibition remains inconclusive.

One explanation may be the existence of distinct neuropsychological profiles for subtypes of violent offenders. This study aims at differentiating groups of affective and instrumental violent defendants on their ability to inhibit behaviour.

Methods: We compared a group of 26 affective defendants with a group of 37 instrumental defendants on several tasks for executive functioning. Results: Affective defendants have more trouble inhibiting an ongoing response on the Stop Signal Task. There were no further differences between affective and instrumental defendants.

Conclusion: Violent defendants constitute of a heterogeneous group, as affective violent defendants possibly have more trouble inhibiting an ongoing response and may therefore be more prone to evoke impulsive violent acts than instrumental defendants.