Look out, tiger moms and helicopter parents: kids may do better in school if they’re more active in the summer, but a new study indicates that over-scheduling your youngsters could be delaying the development of certain key life skills.

The new study was authored by Yuko Munakata, a professor of psychology and neuroscience at the University of Colorado, Boulder, who said, “The more time kids had in less-structured activities, the more self-directed they were and, also, the reverse was true: the more time they spent in structured activities, the less able they were to use executive function.”

According to behavior experts, executive function is a set of thinking skills we develop in life that includes planning, problem solving, decision-making, and regulating thoughts and actions. Apparently kids whose lives are too structured don’t have a chance to develop these skills.

More and more parents are keeping their kids’ schedules full of structured activities to keep them active and engaged, and to help give them in edge in school, sports and extracurricular credits. But experts suggest that children should have a balance between scheduled time and free time that they have to manage on their own. They're finding that the skills learned while managing free time are just as critical as skills developed in structured activities.