This study, funded by National Institutes of Health, the National Science Foundation and private sources, may indicate that peoples aversion to hurting each other may actually be hard-wired into the brain.
The ventromedial prefrontal cortex processes feelings of empathy, shame, compassion and guilt. Damage to this part of the brain, which occupies a small region in the forehead, causes a diminished capacity for social emotions but leaves logical reasoning intact.
Researchers from USC, the University of Iowa, Harvard University and Caltech posed 50 hypothetical scenarios to six people whose ventromedial prefrontal cortices were damaged by strokes or tumors. Their responses were compared to those given by 12 people without brain damage and 12 others with damage in brain areas that regulate other emotions, such as fear.
Researchers are not sure if this study will have any legal implications in criminal cases, but this was not the reason for the study. Instead, researchers want to use this study to explore why some people do not use moral decisions when determining what is right or wrong.
Joshua D. Greene, a Harvard psychologist not involved in the research, said the study showed that moral judgment was shaped by two brain systems — one focused on intuitive emotional responses and another that controlled cognition.
"When one of those systems is compromised, decisions are skewed," he said.
This study may help to explain why some people have no problem sacrificing other people mainly because the people with damage to their ventromedial prefrontal cortex may not understand the harm they are causing to someone else is wrong.