Researchers explored the relationship between childhood leisure activities and creativity in young adults, and the results were stark:
Time spent playing informal sports was significantly and positively related to overall creativity, while time spent playing organized sports was significantly and negatively related to overall creativity.
Perhaps even more interestingly, the difference between those participants whose scores placed them into “above-average” creativity bracket was only about two hours per week of unstructured sport participation throughout their school-age years.
What could account for such distal results? On a theoretical (and, frankly, intuitive) level, informal sports played in unstructured, unsupervised environments capture many of the elements that are linked with the developmental benefits of play for children. These environments offer children the freedom to self-govern, create rules, problem-solve and resolve social conflicts on their own terms.
Organized sports, on the other hand, tend to replicate hierarchical and militaristic models aimed at obedience, replication, adherence to authority, and a number of other qualities that, on a theoretical level, would be unlikely to be conducive to creative development.
[...]
Perhaps the single-most intriguing finding from our analysis was the fact that those individuals whose scores on the creativity assessment identified them as “above-average” were not children who eschewed organized sports in favor of the activities we traditionally associate with creativity (art, music, theater, etc.). Instead, the respondents with “above-average” creativity simply appeared to strike more balance between their time spent in organized and unstructured sport settings.
In fact, those scoring in the “above-average” creativity bracket reported spending 15% of their total childhood leisure time playing informal sports versus 13% playing organized sports. The participants with “below-average” creativity, on the other hand, spent only 10% of their childhood leisure time playing informal sports versus 22% in organized sports.
As is usual in statistical studies, there is an inversion of cause and effect here. Creative children choose unstructured activities, while herd children choose structured activities.
The problem is complicated by modern middle and upper class child raising which imposes highly structured and supervised play on everyone. Clearly a form of child abuse, as is the public schools.