I always thought the real reason was that the cadence of the lessons more closely matched what is possible for a person of average or above intelligence who was motivated to learn. The rate at which information is taught to children in school is kept at a low level because most of the students are not motivated to learn the subjects and instead need to be guided to learn those specific subjects.
The example I was always given for this was the rate at which those same "non-gifted" students would learn subjects they actually care about--like dinosaurs or sports facts. Kids will soak that information up and spend tons of time learning more, but it just isn't useful. Instead we force them to spend less times on those subjects they love and guide them into things society views as more important.
The example I was always given for this was the rate at which those same "non-gifted" students would learn subjects they actually care about--like dinosaurs or sports facts. Kids will soak that information up and spend tons of time learning more, but it just isn't useful. Instead we force them to spend less times on those subjects they love and guide them into things society views as more important.