|London, Dec 03: A biological defect in the way blood flows in the brain rather than a psychological defect could be one reason why some people become criminal psychopaths, a new study shows.
Researchers from the Institute of Psychiatry, King`s College London monitored the emotional responses of six men who had committed repeat offences such as attempted murder, rape with strangulation and grievous bodily harm.
"We`ve never been able to look directly in the brain before and what we found is that when psychopaths were exposed to frightened faces the distress cue didn`t increase the psychopath`s blood flow. It decreased it," Declan Murphy, a professor of psychiatry at the institute, told news agencies.
He added psychopaths might not stop their attacks because they may have learned to dampen their brain`s response to other peoples` distress signals.
All six subjects scored highly on the Hare Psychopathy Checklist, a test which looks for the presence of cunning, manipulative or exploitative behaviors as well as lack of guilt or remorse.
The results were published on Friday in the British Journal of Psychiatry. Their scans were compared to nine healthy volunteers who were also shown images of fearful, happy and neutral faces.
Tom Fahy, professor of forensic mental health and co-author of the study, said the condition may be inherited or acquired through very deprived and abusive childhoods.
He added the findings of the study opened possibilities for new treatments other than counseling therapies and could be used to identify people who had a higher risk of re-offending.
"Psychopaths currently respond pretty poorly to treatment but this biological problem could be used as a marker for people who say they have recovered but actually haven`t," Murphy said.