Interesting, & makes sense on many levels. Sadly football, being a pretty complex game (the reason I love it), probably won't be part of this narrative. You really don't see football happen till kids are high school age. The many rules & discipline needed would probably be stressful for young people with challenges.
I checked the study tables. 28.5% of the kids studied played football. Only basketball was ahead, though really, baseball, soccer, basketball, volleyball, and football were all pretty close.
Although football is more complex than those other sports, one factor in its favour is that it accomodates a broad range of physical sizes and traits, so some kids who might not fit in on other team sports would fit in on a football field.
That surprises me a little, but in a good way. I thought soccer, being so universal, simple & inexpensive would be the game of choice for most. It would be nice if all kids had their choice of these & other options.
Yes, soccer is such an easy decision for parents to get their kids involved in a field sport, gridiron with tackling a tougher decision for parents these days with all the concussion and head injury talk. And yes, a U.S. study.