Harassing behavior isn’t something all children outgrow.

Who knew that our kindergarten classes are full of bullies? A recent study conducted on a Wichita school playground showed that children were the targets of verbal or physical harassment about once every five minutes. The study, conducted by Wichita State University and funded by the National Institute of Mental Health involved about 266 kindergartners — yes, kindergartners!

Not only do we not like to think of innocent 5-year-olds being physically and verbally abusive, this study, reported on in Wednesday’s Journal-World, is geographically a little close to home. We’re not talking about inner-city Los Angeles. This data was collected right here in Kansas.

There were gender differences, of course. Boys gathered in larger groups and focused on competition, teasing children they saw as weaker. Girls’ bullying behavior came out in more subtle ways, usually one-on-one, when they commented on another child’s clothes or excluded her from their group.

It’s probably no surprise that researchers also saw a link to television. “We now have a school system of kids who have been raised on sitcoms,” one of the researchers noted. “Somebody puts somebody down, and the laugh track comes on. Then they slam back with another insult, and it continues again.”

This is a time when we really don’t want life to imitate art. What’s funny in the fictitious world of television is hurtful in real life.

Although, the study found that harassment decreased as students got older and found different ways to deal with their negative feelings, it also found that about 10 percent of the children in the study became chronic victims of abuse. Those children not only were more aggressive and withdrawn, they also were more likely to have poor grades.

Unfortunately, the negative impact of bullying is something that 10 percent may never outgrow. The withdrawal and aggression they express as children may grow into behavior that is increasingly anti-social and even violent.

It’s true that most adults have weathered their share of childhood teasing and insults, but it’s also true that almost all of us can recall a few childhood incidents that still sting at least a little. At the rate measured in the Wichita study, of one insult every 5 minutes, that’s a lot of unhappy memories.

Assuming that the adults in these children’s lives have outgrown their own bullying behavior, they need to teach youngsters how to have more compassion for others and curb their angry reactions. It obviously is a lesson that can’t be taught too early.