Millions of people around the world send their young children to daycare centers – places where children too young for regular school are looked after while their parents are at work, for playtime with other toddlers and often a little instruction, too.  A recent U.S. study looked at these boys and girls' behavior as they continued on in school.  VOA's Melinda Smith has the details.

The study by the National Institutes of Health followed the progress of at least 1,300 children, from birth to the early years of puberty.

Some stayed home with one parent, a nanny or a relative; the rest spent at least 10 hours a week in large daycare centers.  At least one of every four American children spends time in these facilities.

Psychologist Margaret Burchinal of the University of North Carolina, a co-author of the study, found definite behavioral changes by the time the children were nearly 12 years old.

"Our results suggest that children who had more center-based child care – more than, say, two or three years – are showing more [signs of] arguing, talking back to teachers, perhaps hitting and fighting, not following rules, but just slightly more,” Burchinal says.  “Not the kind that would make you go into a classroom and say, 'this child had child care and that child didn't.'”

But there was also good news about these daycare children: many who attended effective child care centers scored higher on vocabulary tests at age 10. 

One mother boasted of her daughter's ability to express herself.  "She's got an outstanding vocabulary, and I'm sure that her time in the school here has contributed to that," she said.

The study evaluated the quality of care given to children ages one to four.  Dr. Burchinal says interaction between teachers and children makes a big difference.

Study co-author Margaret Burchinal

The researchers want to continue the study.  One important question still unanswered is why behavior problems persist for years after daycare is over.

Other studies have shown that disruptive behavior can spread among the children themselves, but then stops when a parent comes into the room.  Authors of the daycare study want parents to be reassured that the greatest influence still comes from a child's mother and father.