Psychopaths may come in two varieties

Some men and women regularly prey on the people around them. Through charm and

manipulation, they take what they want and do as they please. Even the vilest acts

leave these predators remorseless.

People with this personality, who are known to psychologists as psychopaths,

sometimes pay for their deeds by going to jail or psychiatric facilities for

criminals. In the August Journal of Abnormal Psychology, researchers report

finding that psychopaths who evade the law may constitute a breed apart from those

who at some point end up behind bars.

In previous studies, imprisoned psychopaths speaking in front of a camera or

performing other stressful tasks expressed little emotion, either verbally or as

signaled by increases in heart rate and other bodily measures. They also displayed

problems in planning ahead, thinking flexibly, and controlling their impulses.

In the new study, a stressful task induced sharper heart-rate hikes in male

psychopaths who had eluded criminal conviction than in their previously convicted

counterparts or in nonpsychopathic men, reports a team of psychologists led by

Sharon S. Ishikawa and Adrian Raine, both of the University of Southern California

in Los Angeles. Moreover, nonconvicted psychopaths scored highest on a test of

decision-making skills and impulse control. The three groups scored comparably on

an IQ test.

“Heightened physiological reactivity to stress may improve the ability of some

psychopaths to evaluate risky situations and make decisions that benefit their

criminal careers,” Raine says.

The researchers recruited men from five temporary-employment agencies in the Los

Angeles area. Participants, aged 21 to 45, were assured that they couldn’t be

subpoenaed regarding uninvestigated crimes they revealed.

A total of 29 volunteers were identified as psychopaths on a self-report

questionnaire. The test probes for characteristics such as superficial charm,

frequent lying, shallow emotions, impulsiveness, a need for excitement, and a

tendency toward violent outbursts.

Court records showed that 17 of these men had past criminal convictions. Another

26 men recruited from the same agencies weren’t psychopaths and had no previous


Each participant had 2 minutes to prepare a speech detailing his personal faults

before presenting it in front of a researcher while being videotaped, a task

intended to elicit embarrassment and guilt. During this exercise, nonconvicted

psychopaths experienced a much greater rise in heart rate than men in the other

groups did, the researchers say.

This apparent higher emotional sensitivity to risky situations may also have

allowed nonconvicted psychopaths to outscore their peers on a card-sorting task

that requires subtle judgments, the researchers add.

“The stress-induced heart-rate rise in nonconvicted psychopaths is a big

surprise,” remarks psychologist Scott O. Lilienfeld of Emory University in

Atlanta. These results don’t establish that there are basic differences among

psychopaths, Lilienfeld cautions.

It may be that the traits underwriting success in society are the very ones that

help some psychopaths evade capture, Lilienfeld speculates. Having the moxie to

found and run large companies, for example, would put a smart psychopath in a

position to get away with the crimes he or she commits.

Psychologist Robert D. Hare of the University of British Columbia in Vancouver is

skeptical of the new findings. Jumps in heart rate could indicate that

nonconvicted psychopaths simply tried harder on the speech test and may not

reflect differences in their core personality traits, he says.

Bruce Bower has written about the behavioral sciences for Science News since 1984. He writes about psychology, anthropology, archaeology and mental health issues.