Muscle ≠ Brain power (Developing theory)

     We know that football players are stereotypically "not the brightest bulbs" but I have reason to believe that it is not a stereotype. I noticed there was a correlation between the ability to build muscle and the brain capacity. You know the stereotypical "yes coach, no coach," and how they are portrayed in movies as knowledgeless drones. Well, I have encountered many a jock in the YMCA, where I work, with the airhead look on their face (I read faces like Dr. Seuss's books). I can't necessarily explain what I see in those intriguing faces but they obviously have the hamster on the wheel. Have you ever wondered why all the built athletes happen to be airheads? Coincidence? I think not! I'm not done yet. I have a friend who's sibling has down syndrome, and they would wrestle all the time (big redneck family), and his brother would always win. I have heard many other similar stories. There are many other types of disabilities that enhance one sense to make up for the other sense's absence. Think of blind people, they have exceptionally great hearing, deaf people have great vision, paraplegic have strong arms. The brain tries to even things out as much as possible, so if the left arm is missing, the right arm compensates for the left's absence by strengthening the right. It is the same between body and brain. Why are all nerds/geeks stereotypically scrawny? Why are all jock stereotypically buff? If you have anything to add to this developing theory, please comment, I could use the feedback.