Evidence suggests there are neural differences in the brains of offenders and non-offenders
Much of this evidence involved individuals with antisocial personality disorder (APD)
APD is associated with reduced emotional responses and a lack of empathy, features commonly associated with criminals
Prefrontal cortex
Raine studied the brains of people with APD and found that individuals with APD have reduced functionality in the prefrontal cortex, which regulates emotional behaviour
Raine et al. also found an 11% reduction in the volume of grey matter in the prefrontal cortex
Mirror neurons
Research suggests that people with APD experience empathy more sporadically than the rest of us
Keysers found that only when offenders were asked to empathise with the victim on the screen did their empathy reaction activate (controlled by mirror neurons in the brain)
Individuals with APD may have a neural 'switch' that can be turned on and off
MAOA gene
A mutated variant of the MAOA gene is inherited (MAOA-L) and this codes for the MAOA enzyme
Thus, demonstrating the impact of abnormalities in a person’s neurochemistry on violent and potentially criminal behaviour
Neurochemistry of offending behaviours
Noradrenaline hyperactivity - lowers the threshold for aggressive responses to the fight-or-flight system, heightens arousal and vigilance
Serotonin hypoactivity - low levels are linked to the inability to inhibit responses to emotional urges
Dopamine hyperactivity - high levels make it difficult to delay gratification or consider consequences - reckless behaviour, increases reward-seeking behaviour - criminal behaviour may provide rewarding/reinforcingdopamine highs.
