In contrast to an earlier finding, it does not appear children who watch a lot of television wind up with behavior problems in school, researchers reported on Monday.

If there is an association, it may be that the exhausted parents of already overly active children are more likely to let them watch TV to give themselves a break, and not that TV itself leads to attention deficit-hyperactivity disorder, or ADHD, the report from Texas Tech University in Lubbock said.

The findings were based on an evaluation of data from a survey of parents and teachers of 5,000 U.S. children over a 2-year period, to determine if TV viewing habits during the kindergarten year resulted in ADHD in first grade.

“The results of the present study do not indicate the presence of an important relationship between television exposure and subsequent attention problems,” said the study published in the March issue of “Pediatrics,” the journal of the American Academy of Pediatrics.

That finding conflicts with the conclusion of a 2004 study in the same journal, possibly because of differences in methodology, the authors said.

The earlier study, which used a different database, found each hour of TV watched during ages 1 to 3 increased the risk of attention problems by 10 percent at age 7.

But the new study pointed out that “ADHD, although identified by other names, has been recognized as a disorder of childhood well before children had television to watch.”

Earlier studies have found no support for the idea that parenting causes the disorder, although environmental factors around the time of birth have been linked in some studies, as has exposure to environmental toxins, it added.

“Researchers have learned that much of child development is reciprocal, with characteristics of a child influencing the way that child is parented in addition to parenting influencing characteristics of a child,” the study said.

“It may be that exhausted parents of very active and inattentive children resort to using the television as a ‘babysitter’ more commonly than do parents of less active and more attentive children,” it said.

“Thus, the relationship between early television viewing and later attention problems may be linked to child temperament as much as or more than television causing children to be inattentive” it concluded.