A pair of brain regions work together to assess the threat of punishment and override our selfish tendencies.
Whether you subscribe to the Ten Commandments, the Golden Rule or some instinctive moral code, society functions largely because most of its denizens adhere to a set of norms that allow them to live together in relative tranquility.
But, why is it that we put a vast amount of social resources into keeping stealing, murdering and other unfair (not to mention violent and illegal) acts to a minimum? Seems it all comes down to the fact that most of us don't cotton to being punished by our peers.
"The reason why punishment for norm violations is important is that it disciplines the potential norm violators," says Ernst Fehr, an economist at the
In the new study, Fehr and colleagues uncovered activity in two areas of the brain underlying the neural mechanism involved in conforming to society's values. They further determined that subjects with Machiavellian personalities—a strong sense of self-interest, opportunism and manipulation—have heightened activity in one of these regions, which the authors believe is related to assessing the threat of punishment.
Jorge Moll, principal investigator of the cognitive and behavioral neuroscience unit at the Rede Labs-D'Or Hospitals in Rio de Janeiro, says the most interesting findings were that individual scores on Machiavellianism predicted "how much a given subject will change his behavior depending on the presence of punishment," and "that the level of activity within the lateral orbitofrontal cortex is strongly related to Machiavellian personality style."
Researchers say the results could have wide-reaching implications, potentially paving the way to understand—and perhaps one day reverse—the neurobiology behind psychopathic and sociopathic personalities. They intend to repeat the study with patients suffering from antisocial anxiety and personality disorders to determine if their behavior can be explained by a lack of impulse control or a poor assessment of punishment.
Fehr argues the results could also impact the criminal justice system since the dorsolateral prefrontal cortex does not fully develop until after a person is around 20 years old.
"This area seems to be critically important in overriding self-interest," he says. Thus, "you just can't treat an immature adolescent the same way as a mature adult—that's at least my view of doing justice." It's unclear whether judges and juries see it that way, however.
Kemo D. (a.k.a. no.7)