Crime Library: Criminal Minds and Methods

Dr. Robert Hare: Expert on the Psychopath

Psychopathy and the Brain

In a segment of "The Mind," a PBS documentary that looked at many aspects of behavior and the brain, Hare assessed "Al," a middle-aged man with 46 convictions for criminal acts from drugs to bank robbery.  Using a neurological diagnostic test to eliminate obvious brain damage, Hare's team then gave Al tests that measure the processing of language.  The question under investigation was whether or not there is something measurably different about the brain of a person who has been so socially deviant.

In a clinical interview, Al admitted to being extraordinarily good at lying; said he was never diagnosed as hyperactive; grew up in a violent area of Vancouver, BC, in Canada; and recalled incidents in which he had acted out in anger or in irrational ways, just to prove something about his macho self-image.  He felt no concern for his victims, he says, or any remorse. 

By the time he was 15, he was in prison, where he mingled with hardcore prisoners.  He became more sensitive to how others treated him, and more reactive.  He ended up stabbing someone.

Hare first tested Al on a dichotic listening device, through which words came to him via alternating ears.  The results appeared to be consistent with the evidence that psychopaths may not process words primarily by left hemisphere activity, but instead involve both hemispheres equally.

The next test was even more revealing.  Al watched different words come onto a monitor screen.  Some of the words were generally considered to have emotional associations and others were considered neutral.  Whereas most people respond more quickly to emotional words, Al's response time was the same to both emotional and neutral words.

"The impetus for this research," Hare says for the documentary, "is the clinical observation that psychopaths can say one thing and do something else.  This has perplexed a lot of people.  Is it simply lying, dissimulation, or hypocrisy?  Probably not.  There's more than that involved in it."

Hare points out that some people have described psychopaths as somewhat robotic, two-dimensional, emotionally shallow, and lacking in conscience.  They may know intellectually they should not do something, but without the feeling component there could be less motivation to respond to the moral imperative. Their inhibitions for antisocial or violent behavior are much weaker than in normal individuals, and they readily learn and adopt behavior patterns that involve manipulation, deception, and violence to attain their own ends.

  Because they don't understand the feelings of others and dont feel remorseful for harming them, psychopaths can easily rationalize their violence or deception as acceptable behavior. 

Hare and his colleagues continued this research to learn more about the brain's involvement in psychopathic behaviors.  They used whole brain functional magnetic resonance imaging (fMRI) to see if there were neurological manifestations of the way psychopaths process different types of words. When non-psychopaths processed negative emotional words (e.g., rape, death, cancer), activity in the limbic regions of the brain increased.  For psychopaths there was little or no increased activity in these regions.  Curiously, however, there was increased activity in other areas.  In short, the emotional word does not have the same limbic implication for psychopaths that it does for normal people.

Limbic system
Limbic system

"They seemed to be like Spock or Data on Star Trek," Hare explains, "What I thought was most interesting was that for the first time ever, as far as I know, we found that there was no activation of the appropriate areas for emotional arousal, but there was over-activation in other parts of the brain, including parts of the brain that are ordinarily devoted to language.  Those parts were active, as if they were saying, 'Hey, isn't that interesting.'  So they seem to be analyzing emotional material in terms of its linguistic or dictionary meaning."       

Yet Hare does not think that psychopathy is caused by brain damage.  Instead, he says, "there are anomalies in the way psychopaths process information.  It may be more general than just emotional information.  In another functional MRI study, we looked at the parts of the brain that are used to process concrete and abstract words. Non-psychopathic individuals showed increased activation of the right anterior/superior temporal cortex.  For the psychopaths, that didnt happen."

Hare and his colleagues then conducted an fMRI study using pictures of neutral scenes and unpleasant homicide scenes.  "Non-psychopathic offenders show lots of activation in the amygdala [to unpleasant scenes], compared with neutral pictures," he points out. "In the psychopath, there was nothing.  No difference.  But there was overactivation in the same regions of the brain that were overactive during the presentation of emotional words.  It's like they're analyzing emotional material in extra-limbic regions."  

Does this mean they're trapped in a certain way of being?  Is treatment even possible?