By Carey Goldberg, Globe Staff, 7/15/2003
Scientists may slowly be closing in on the psychopath.
New research tools, from brain scans to psychological tests, are yielding more sophisticated insights into what makes psychopaths such cold-blooded predators, raising the prospect of improved tests to identify them and possibly even treatment.
''We can treat most other emotional disorders pretty successfully, and we will be able to treat this one soon,'' said Dr. James Blair, a researcher at the National Institute of Mental Health.
Psychologists estimate that one in every 100 people is unfeeling enough to qualify as a psychopath, with an especially heavy concentration among criminals. The ranks include serial killers such as Ted Bundy, who charmed and killed dozens of young women in the 1970s, and cannibal-murderer Jeffrey Dahmer, who fatally seduced 17 men and boys before he was caught in 1991, as well as a great many other people who never commit a crime punishable by law, but go through life heartlessly using and manipulating others without remorse.
Blair is an admitted optimist, but even skeptical scientists say that the last few years have brought progress, as researchers have largely reached agreement on how to define a psychopath and have begun pinpointing what happens in their brains.
Even the last few weeks have brought intriguing new findings. Among them: A psychological test designed to detect unconscious or frowned-upon attitudes picked up a decided tendency among psychopathic murderers to have abnormally positive attitudes toward violence, British researchers reported in the May 29 edition of the journal Nature.
No one has ever pinned down that attitude among psychopaths before, said Nicola Gray, coauthor of the Nature paper, because they relied on explicit questions, and psychopaths lie a lot.
Spinal taps on more than 50 imprisoned criminals in Sweden produced new evidence that psychopaths may have an imbalance of the brain chemicals serotonin and dopamine, according to a paper in last month's Journal of Neurology, Neurosurgery and Psychiatry.
Experiments using brain scanners while psychopaths perform various tasks also have been accumulating.
They suggest that ''the psychopath finds it difficult to process, handle, or use emotional material in the same way the rest of us do,'' said Robert D. Hare, professor emeritus of psychology at the University of British Columbia and widely considered the world's foremost authority on psychopaths.
Of course, that is the obvious problem, the very definition of a psychopath: They lack normal feelings, like empathy and remorse. And researchers have known for decades that psychopaths also tend to show some unusual physical responses: They sweat less and generally exhibit less distress when exposed to frightening or threatening stimuli, for example.
But research is now focusing on the brain abnormalities in psychopaths, said Dr. Bruce Price, chief of neurology at McLean Hospital in Belmont.
And, he said, ''the seismic shift is that, up until a decade or so ago, this was the realm of psychologists and sociologists. We now are at the point where biological science can try to make sense of this.''
That point has been reached partly thanks to new tools like brain scanners, researchers say, but also partly thanks to Hare's development of a broadly accepted clinical standard for who is a psychopath, a test called the PCL-R, or psychopathy checklist-revised.
The PCL-R allows psychologists to rate a subject's level of psychopathic behavior and emotional makeup by extensive interviewing and examination of his or her record. (It is almost always a man.) It measures how callously the subject has used others, for example, and how antisocial and unstable the subject's life has been.
The development and broad acceptance of the PCL-R gave researchers a basis for making sure they compared apples to apples across studies. Research on psychopaths has ''skyrocketed'' in recent years, Hare said, with particular interest in Scandinavia, Germany, the United States and Canada. It was, he said, ''a ruler not made out of rubber.''
Among all those researchers, those examining brain activity have tended to find abnormal activity in the amygdala, a part of the brain seen as the seat of basic emotions like fear, and the orbito-frontal cortex, which is involved in helping people adjust their behavior in response to reward or punishment.
Some studies also indicate problems in the connection between the deep, emotional brain and the thinking part of the brain.
That anatomical finding combined with psychological tests show with new precision that psychopaths have problems processing emotional information, particularly things that make normal people afraid or sad, Blair said.
And consider, he said, that ''the best way of teaching a child to feel guilt about harming another individual is to focus the child's attention on the victim's sadness. But that sort of socialization technique doesn't work well with individuals with psychopathy,'' because they tend to be unable to feel empathy and to respond poorly to cues associated with negative emotions.
In essence, Hare said, it appears that ''emotion for the psychopath is like a second language,'' one he or she must struggle to speak and never master deep down. Emotions for psychopaths are abstractions, much as they are for Data or Mr. Spock on ''Star Trek,'' he said.
Even their murders tend to be dispassionate: A study of 125 Canadian murderers found that among those with high psychopath scores on the PCL-R, 93 percent of their killings were ''instrumental,'' practical, rather than crimes committed in the heat of high emotion. That cold-blooded quality makes them particularly dangerous, experts say.
So, with all this research, how about a definitive test to catch the potential serial killers before they start killing?
It is conceivable, researchers say, but not yet doable: ''The false positive rate would be horrific,'' Hare said. But, eventually, it should be possible to combine the telltale signs in psychopaths' brains -- once it becomes much more clear what those are -- with a clinical tool like the PCL-R and get an excellent predictor of future danger, he said.
But to get there would require large-scale, expensive studies, he added.
The psychological test of attitudes toward violence published in Nature may be usable to predict how violent a psychopath is likely to be, but more research is needed, according to Gray. A similar test shows promise in revealing attitudes toward pedophilia, she said.
But a Harvard expert on the test used in the Nature study, which is called an Implicit Association Test, expressed concern: ''The IAT is not, and never will be a test like a DNA test,'' said Mahzarin Banaji. ''It is meant for research, not diagnosis,'' she said.
As for treatment, past research has shown that most conventional treatment, like group therapy, only makes psychopaths worse; it seems to train them in manipulating people and faking emotions.
But Blair and some others believe that, within a few years, a drug may be developed to treat psychopaths. People with depression and anxiety problems can be helped by adjustments of their brain chemicals, he said, and psychopaths effectively have the opposite problem in that they feel too little.
''You would be able to help the systems that aren't working particularly well by using a drug, so long as we understand what's not working well,'' he said. So, perhaps ''we can give emotions to people who lack them.''
Carey Goldberg may be contacted at goldberg@globe.com.
This story ran on page C1 of the Boston Globe on 7/15/2003.
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