Study Links Day Care With Child Aggression

April 19, 2001 -- Does day care breed bullies?

A 10-year, 10-city federal study found that 4 ½-year-olds who spent the most time in day care away from their parents were more likely to be aggressive and exhibit behavioral problems when they got to kindergarten.

The National Institute of Child Health study, billed as the largest long-term study of child care ever conducted, followed more than 1,364 children in a variety of settings, and based its conclusions on ratings of the children by mothers, caregivers and kindergarten teachers. Findings were presented today at the biennial meeting of the Society for Research in Child Development in Minneapolis.

Jay Belsky, a research psychologist at Birkbeck College in London and a principal researcher on the study, said children who spend more than 30 hours per week in child care "scored higher on items like 'gets in lots of fights,' 'cruelty,' 'explosive behavior,' as well as 'talking too much,' 'argues a lot,' and 'demands a lot of attention.'"

The study found the findings held up regardless of family background.

Day-Care Kids Tested Better

However, the study also had findings that appeared to show benefits of day care — at least day care that's of a high standard.

It found that 4 ½-year-olds in high-quality day care scored higher on thinking and language tests than did children who stayed home or received lower-quality care.

"This work documents more strongly than ever before that better-educated and trained teachers are providing more language stimulation so that that the children they take care of do better on tests regardless of family background," said Dr. Martha Cox of the University of North Carolina at Chapel Hill, another principal investigator in the study. "Quality indeed makes a difference."

Researcher Not Surprised

Bob Pianta, a professor at the University of Virginia and another of the principal investigators, said it is not surprising that day-care kids, who are accustomed to be being in different settings, would be more assertive or aggressive.

"These are children who've accumulated a whole lot more experience with peers, as a function of being in child care, than have children who have many fewer hours of care," Pianta said. "It could be the case that what you see is sort of a much more experienced bit of behavior in peer relations, and a willingness to kind of go out there and, in a sense, mix it up with other kids in the classroom."

Investigators said that although kids in day care tended to have behavioral problems, their problems were "well within the normal range," and could possibly disappear later. Therefore, Pianta stressed a lot more follow-up work needs to be done.

"These could be children who could end up … showing leadership attributes," Pianta said. "You know, being more outgoing and the like. We just don't know."

As a parent himself, Pianta sees the results as another reason to be wary in child rearing.

"I think this is a lot about how you balance the care of children with the needs to provide resources for the family and work and all the relationships that go in a family," Pianta said.

"That is a balancing act all the time. So this is just part of, a signal that there's another piece of the balancing act we ought to be paying attention to."

ABCNEWS' Jim Hickey and ABCNEWS Radio contributed to this report.