Although many of us think of bullying as a normal part of growing up, it is increasingly seen as a public-health problem. Research has found that bullies and their victims may end up with long-term psychiatric problems, including addictions, and may grow up to abuse their spouses. A new study from the University of Washington looked at what factors early in childhood might lead kids to become bullies later.

What the researchers wanted to know: How does the home environment at age 4 affect a kid's chance of becoming a bully later?

What they did: The researchers looked at children who were part of a national long-term study. The children were ages 6 to 11 when their mothers did the 2000 interview for the study. Mothers were asked, among other questions, whether a statement about their child bullying other kids, or being cruel or mean to other children, was "often true," "sometimes true," or "not true." That wording might sound as if it wouldn't get good answers, but it has actually been shown to be a fairly reliable way to find out if children are bullies. About 13 percent of the children were reported to be bullies by their mothers. From the same long-term study, the researchers also knew what the home environment had been like at age 4 for the 641 children.

What they found: The researchers looked at three early-childhood factors: emotional support from parents, cognitive stimulation, and television watching. They found that kids who had good emotional support at age 4 were less likely to be bullies at ages 6 to 11. They also found that early cognitive stimulation reduced the chance that children would bully others later (some research has shown that kids who are less secure academically are more likely to be bullies). Also, kids who watched more TV at age 4 were more likely to become bullies; the likelihood went up by 6 percent per hour of TV viewing a day. Other variables could easily be responsible for such patterns—for example, both bullying and television-watching vary depending on a child's race, age, and sex. But, in this analysis, the researchers controlled for those variables and also for socioeconomic status (parental income and education).

What the study means to you: Giving more emotional support and intellectual challenge to kids, even when they're very small, may help them succeed later—not just academically but also by improving their mental health. And, of course, this research can be added to a long list of studies suggesting that watching a lot of TV is not good for kids.

Caveats: Different mothers might have different definitions of "bullying," and some might have been unwilling to admit that their little darlings had ever been cruel to anyone.

Find out more: A 2001 article from the American Medical Association's newspaper explains why bullying is being thought of as a public-health problem.

Read previous health briefs at USNews.com for more on childhood violence and the effects of television.

Read the article: Zimmerman, F.J., et al. "Early Cognitive Stimulation, Emotional Support, and Television Watching as Predictors of Subsequent Bullying Among Grade-School Children." Archives of Pediatrics & Adolescent Medicine. April 2005, Vol. 159, pp. 384–388.

Abstract online: http://archpedi.ama-assn.org