October 1, 2008

Study Finds “Fight Or Flight” Hormone Limits Aggression

British researchers said on Wednesday that the stress hormone cortisol, involved in our "fight or flight" response, might also limit aggressive antisocial behavior.

The researchers found that in stressful situations cortisol levels failed to spike normally in boys with behavioral problems. The study suggests that the roots of antisocial behavior may be more biologically based than thought.

Graeme Fairchild, a psychologist at the University of Cambridge, who led the study, said most research has looked at social factors like peer groups, family life and socioeconomic factors.

"These findings basically indicate that antisocial behavior is probably more biologically based than many people recognize and is similar to conditions like depression and anxiety."

He said an estimated 3 percent to 5 percent of children in the developed world exhibit antisocial behavior -- such as vandalism, mugging and starting fights -- that can get them expelled from school, in trouble with the police or even sent to jail.

The research evaluated 100 boys from mainstream schools aged between 14 and 18 and another 75 adolescents with known antisocial behavior. Males are four times more likely than females to behave antisocially.

The researchers first made sure the boys had similar cortisol levels, then they were brought to a lab to monitor changes in the hormone during a game rigged to provoke stressful responses.

The data showed that Cortisol levels in the students without aggression problems spiked during the experiments but remained steady in youths who had exhibited antisocial behavior.

Fairchild said the hormone is important in helping people form memories and people with high levels tend to be more cautious and better at controlling their impulses.

"They looked as if they weren't under stress even though they said they were because their bodies didn't show it," Fairchild said.

The findings published in the journal Biological Psychiatry said better understanding biological causes of antisocial behavior raises the possibility that drug treatment could help some people curb their aggression.


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