Even in cartoons, kids fight.

Adult intervention can help moderate antisocial behavior among children.

Scientists studying the degree to which brain function, parental involvement and environment determine antisocial outbursts in children have found that social support and intervention can successfully moderate misbehavior.

Researchers at the University of Michigan studied the amygdala — the part of the brain that processes fear and impulsive reactions — for clues about extreme behavior in children. The amygdala is associated with aggressive behavior, anxiety disorders and depression. Once that region of the brain is stimulated, they found, some people become anxious and overreact to perceived threats.

According to the study, if the child is not getting help from others — family, neighbors or professional — then the link between the amygdala and anxious behavior is stronger.   The tendency to overreact can be altered by a child’s environment, and the same researchers found in another study  that impulsive kids are at higher risk of engaging in antisocial behavior if they live in ‘dangerous’ neighborhoods.

Scientists Michigan’s Institute for Social Research used neurogenetics, which combines genetics, neuroscience and psychology, to understand the propensity to extreme behavior. They also drew a distinction between normal childhood misbehavior and serious behavioral issues that will persist into adolescence.

Throwing a tantrum is common, the study found, but a number of other behaviors might indicate other issues. Among those were cruelty to animals, lack of guilt, lying, deceptive behavior and an inability to change behavior after punishment.

“The results of this test aren’t really meaningful until age 3 or 3 1/2,” said researcher Luke Hyde.  “Before that, many of these behaviors are fairly common and don’t predict anything.  But after age 3, if children are still behaving in these ways, their behavior is more likely to escalate in the following years rather than improve.”

Hyde found that even children who regularly exhibited antisocial behavior did well when parents or others  intervened by spending time with their children, using timeouts instead of physical punishment and rewarding good behavior.

julie.cart@latimes.com

Twitter: @julie_cart