Testing theories about psychopathy's roots

The most dangerous criminals are psychopaths, described by researcher Robert Hare as "predators [whose] game is to find and exploit prey." Psychopathic criminals, Hare says, are grandiose, egocentric, manipulative, dominant, cold-hearted, conscienceless, and impulsive. He estimates that 15 to 20 percent of persistent criminals are psychopaths, and says that "a psychopath released from prison is five or six times more likely than other offenders to commit another offense and perhaps six or seven times more e likely to commit a violent offense."

Much recent research has focused on the cognitive deficits of psychopaths, with two theories currently prevailing. One is the "violence inhibition mechanism" model, which suggests that psychopaths lack a normal response to distress cues from other people. . A second model, the "response modulation" hypothesis, postulates that psychopaths have difficulty shifting their attention from the performance of a behavior to an evaluation of its consequences. "This model," L. Fisher and R. J. R. Blair say, "specific cally predicts that individuals with psychopathy will be more likely than non-psychopathic individuals to persist in a previously rewarded response, even if the rate of punishment for this response increases." New research by Fisher and Blair suggests tha at both theories are true-and that deficits in response modulation and violence inhibition may stem from the same neurological roots.

Fisher and Blair studied 39 boys between the ages of 9 and 16, all attending a special school for children with emotional and behavioral problems. Subjects took a verbal IQ test and were administered the Psychopathy Screening Device, a rating scale for ps sychopathic behavior in children. In addition, the children were given two tests:

• A card-playing game, designed to measure the children's ability to modulate their responses in reaction to changing stimuli. In this test, the children turned over cards in a deck, receiving a token each time a "Y" card was turned up and losing a toke en each time an "N" card was turned up. Over 100 trials, the number of Y cards gradually dropped from 100% to 10%. Children could choose to stop playing at any time.
• A "moral/conventional distinction" test, in which the children were read four stories about moral transgressions (hitting, stealing, smashing a piano with a hammer, etc.) and four stories about "conventional" transgressions (a boy wearing a skirt, a c child leaving class without permission, etc.). The children were asked if the actions in the stories were acceptable, and further asked, "If there was no rule about people doing [the transgression], would it be okay?," and "If the teacher in the school sa aid that anybody can do [the transgression], would it be okay to do it?" Scores were based on the children's understanding that moral transgressions are unacceptable, even if there are no rules against them, because they cause distress in others.

"Cognitive impairment and its relationship to psychopathic tendencies in children with emotional and behavioral difficulties," L. Fisher and R. J. R. Blair, Journal of Abnormal Child Psychology, Vol. 26, No. 6, December 1998, pp. 511-520. Address n not listed.