A new study by a Harvard University-led team has shed some light on the underlying causes of psychopathy. Explaining their findings in the journal Neuron, these researchers describe how they uncovered the neurological “wiring” that makes psychopaths so impulsive and sometimes dangerously reckless.
Although it’s previously been assumed that it’s their lack of empathy that engenders reckless choices and actions, this team have concluded that it’s the appeal of the short-term reward that’s really motivating their decisions.
“Because it's the choices of psychopaths that cause so much trouble, we've been trying to understand what goes on in their brains when they make decisions that involve trade-offs between the costs and benefits of action,” senior author Josh Buckholtz, an associate professor of psychology, said in a statement.
In order to achieve this, his team took a mobile brain scanner to 50 incarcerated prison inmates that had shown psychopathic tendencies in the past. While hooked up to the MRI machine, the prisoners were then given a “delayed gratification” test, wherein they had to decide whether to take less money from a pile sooner, or wait and get more money hours down the line.
The more impulsive and thus more psychopathic individuals required gratification far sooner, as expected. Individuals with high psychopathy scores showed greater activity in the region of the brain associated with immediate reward.
As they pondered on their decisions, the MRI scanners were looking at two key regions of the brain – one that is associated with “mental time travel”, which allows us to think about the future consequences of our actions, and one that is associated with more immediate decision-making.
The team found that the wiring between these two sections of the brain was far weaker in the more psychopathic inmates. Remarkably, the correlation between the strength of the wiring and the tendency towards impulsivity was so strong that they could use the brain scans alone to correctly predict how many times the inmates had been convicted of crimes.