Psychopathy
Some psychopaths are able to detect the emotions of others with such a theory of mind and can mimic caring and friendship in a convincing manner, often in an effort to exploit others. While some psychopaths can detect what others are feeling, they do not experience any reciprocal emotion or sympathy. However, some research indicates that components of neural circuits involved in empathy may also be dysfunctional in psychopathy.[48]
[edit] Enjoyment of others' suffering
The same ability may underlie schadenfreude (taking pleasure in the pain of another entity) and sadism (being sexually gratified through the infliction of pain or humiliation on another person). Recently, a functional MRI study conducted by Jean Decety and colleagues at the University of Chicago has demonstrated that youth with aggressive conduct disorder (who have psychopathic tendencies) have a different brain response when confronted with empathy-eliciting stimuli.[49] In the study, researchers compared 16- to 18-year-old boys with aggressive conduct disorder to a control group of adolescent boys with no unusual signs of aggression. The boys with the conduct disorder had exhibited disruptive behavior such as starting a fight, using a weapon and stealing after confronting a victim. The youth were tested with fMRI while looking at video clips in which people endured pain accidentally, such as when a heavy bowl was dropped on their hands, and intentionally, such as when a person stepped on another's foot. Results show that the aggressive youth activated the neural circuits underpinning pain processing to the same extent and, in some cases, even more so than the control participants without conduct disorder. However, aggressive adolescents showed a specific and very strong activation of the amygdala and ventral striatum (an area that responds to feeling rewarded) when watching pain inflicted on others, which suggested that they enjoyed watching pain. Unlike the control group, the youth with conduct disorder did not activate the area of the brain involved in self-regulation and moral reasoning.[49]