During the study, researchers analysed data collected in a previous nationally representative survey of elementary school aged children and their families and a qualitative study conducted in two medium-sized communities in the American Midwest.
According to Sandra Hofferth, from University of Maryland, previous studies have raised the spectre of the "hurried child syndrome," but little has been known about the proportion of children whose extra-curricular activities might be excessive and whether these were associated with child anxiety, alienation, depression, fearfulness and reduced self-esteem.
She conducted the research with a team from Central Michigan University and Oakland Community College.
The analysis revealed that only one-quarter of children met the criteria of "hurried" - three or more activities or more than four hours devoted to activities within a two day period; 58 percent were "balanced," pursuing one or two activities, and 17 percent reported no activities.
Children of mothers with more education and higher family incomes were busier.
When compared with children in the balanced group, children with higher activity levels did not have higher levels of stress or lower self-esteem, while, children with no activities were the most withdrawn, socially immature, and had the lowest self-esteem.
"The notion that we're raising a generation of young children stressed-out by overscheduled lives doesn't appear to square with the facts," said Hofferth.
"Even a high level of structured activities does not appear to be emotionally stressful for children.
"Highly active children don't differ from children with a more balanced set of activities. Contrary to popular belief, children who are most at risk of being depressed, anxious, alienated, and fearful are those with no activities," she added.