Do Mock Jurors Equate Offenders to Their Brains? Effects of Neuroscientific Testimony on Punitiveness

• In Event: Challenging Perceptions: Rethinking Detainees, Former Prisoners, Human Rights and Dispute Resolution

Abstract

In growing numbers of court cases, neuroscience is presented to document the mental state of the defendant at the level of the brain. While a limited body of research has tested the effect of questioning the culpability of the defendant by documenting abnormal brain function and structure, no study has yet tested the alternative use of neuroscience; that is to assert the culpability of the offender by documenting normal brain function in the defendant.

In this online mock court experiment, 1000 mock jurors sentenced a hypothetical offender, described as having committed a serious assault on impulse. The defence testimony either made no reference to self-control or described the offender as typically displaying normal or low self-control. In turn, this level of self-control was described either in cognitive or neurobiological terms. When the offender was described as typically displaying normal self-control, the neurobiological testimony significantly increased punitiveness. In contrast, when the offender was described as typically displaying low self-control, the neurobiological testimony moderately reduced punitiveness. Hence neuroscience exerted a larger effect on punitiveness when used to document normal, compared to low, self-control. Therefore, lay people may be more receptive to neuroscientific means of asserting, than questioning, the culpability of the defendant.

Authors

• Robert Blakey, University of Oxford

• Tobias Kremsmayer, A