Vol. 6, No. 2, 2000 Page 2&5
| Vol. 6, No. 2, 2000 Page 2&5 |
Like a busy CEO, your brain is constantly making long-term plans and carrying them out. This activity requires a host of cognitive processes, known collectively as “executive functioning” (EF), that allow you to set goals, make and modify mental “models” of actions, organize your activity, focus your attention selectively, and avoid impulses and distractions that could sidetrack you from accomplishing your aims.
Recently, Alex Morgan and Scott Lilienfeld investigated the association between antisocial behavior and EF skills, which are believed to be mediated largely by the frontal lobes of the brain (see related article on page 1). The researchers pooled data fro om 39 studies, involving more than 4,500 participants. Analyzing the results, they concluded, “Overall, antisocial groups performed .62 standard deviations worse on EF tests than comparison groups; this effect size is in the medium to large range.”
The researchers note that the EF deficits found in antisocial individuals could not be conclusively linked to specific areas of the frontal lobes, an issue which they say could be resolved by brain imaging studies (see p. 1). In addition, they say, the st trength of the correlation between EF deficits and antisocial behavior varied according to the types of antisocial behaviors exhibited by study subjects, with criminality and delinquency showing a stronger relationship than conduct disorder, psychopathy, or clinically defined antisocial personality disorder. The researchers also note that some evidence of deficits in skills other than EF also was revealed by the studies they evaluated.
Nonetheless, Morgan and Lilienfeld say, “The results of this meta-analysis indicate that there is a robust and statistically significant relation between antisocial behavior and executive functioning deficits.”
“It would appear,” the researchers conclude, “...that neuropsychological deficits are present in many of these youngsters when they are first diagnosed in the preschool years.”
The verbal deficits seen in Speltz et al.s’ subjects may be a more robust finding than the finding of EF deficits. When the researchers controlled for disruptive behaviors, the clinic boys did not differ from normal controls on measures of EF, but still s showed reduced verbal ability. However, the researchers note that executive function is very difficult to measure in preschool children, and that one study of older children found that EF deficits were a stronger predictor of physical aggressiveness than were poor verbal skills.
“A meta-analytic review of the relation between antisocial behavior and neuropsychological measures of executive function,” Alex B. Morgan and Scott O. Lilienfeld, Clinical Psychology Review, Vol. 20, No. 1, January 2000, pp. 113-136. Address: Alex x B. Morgan, Department of Psychology, Emory University, Atlanta, GA 30322, abmorga@emory.edu.
“Neuropsychological characteristics and test behaviors of boys with early onset conduct problems,” Matthew L. Speltz, Michelle DeKlyen, Rose Calderon, Mark T. Greenberg, and Philip A. Fisher, Journal of Abnormal Psychology, Vol. 108, No. 2, 1999, p pp. 315-325. Address: Matthew L. Speltz, Psychiatry and Behavioral Sciences, University of Washington, Box 359300-CL08, Seattle, WA 98195.