19 January 2000

The Meanest Kid In School

by Kate Melville

An interesting study, has just been released that as one of it's key tools asked students to name the three boys in class who had the most fights and were the 'meanest'.

This unusual line of inquiry was part of a four-year study of thirty eight boys with behavioral problems, conducted by the University of Chicago. The study also measured the salivary level of the stress hormone Cortisol, which is secreted in response to stressful or threatening situations.

The results indicate that a low level of cortisol in young boys (aged seven to twelve) seems to be linked to the onset and persistence of extremely aggressive behavior. Indeed the boys with low levels of cortisol were three times as likely to be singled out as mean or combative by their classmates.

According to Keith McBurnett, Ph.D., assistant professor of psychiatry at the University of Chicago and lead author of the study the findings suggest a, "lasting biological and not just parental or short-term environmental component to this type of chronic antisocial behavior. Children with persistent conduct disorder may have genes that predispose them to produce certain hormones differently, or their hormone production may have been altered before or soon after birth. Boys with consistently lower cortisol levels may not be as afraid of retribution. In many aggressive children, the system that responds to the threat of punishment does not react normally.

They may not feel stress in the same way and so they don't avoid stressful situations." Psychiatrists may be able to use these results to try and understand differences between adolescent males who are going through a short period of aberrant behavior and those with a severe and lasting conduct disorder. Children with persistent conduct disorder be liable to remain disruptive for decades and are hugely over represented in statistics relating to crime and violent acts.

Each participant in the study was given a through psychiatric evaluations and interviews were conducted with parents, teachers and classmates. Researchers found that cortisol levels were "strongly and inversely related to aggressive conduct disorder, peer aggression nominations and oppositional defiant disorder" (all participants had similar IQ's, socioeconomic and ethnic characteristics).

Twelve boys with low levels of cortisol averaged 5.2 symptoms of conduct disorder, compared to 1.5 symptoms in the twenty six boys who had higher levels. One third boys with low cortisol were seen by their classmates as the "meanest" in the class.

While the link between cortisol levels to aggressive behavior is not understood, variation in levels may be a useful indicator for abnormalities in the stress hormones that influence the body's response to conflict.

So if your kid is the meanest in school test their cortisol levels, or failing that steer them in the direction of a career where aggression is a bonus not a handicap like software mogul, police officer, taxi driver or professional sportsperson.