"The parents intentionally give their children this autonomy and freedom because they believe it's the best way to motivate kids." This is basically the philosophy behind self-directed learning: unschooling as well as learning communities like Sudbury schools, liberated learners centers, and agile learning centers.

I work at one of these schools, and our kids are really good at paying attention. ADD is a real thing and still affects some of them, but we also have a lot of kids who were diagnosed with ADD and it turns out when they are interested in what they're doing, their attention span is completely normal.