Doesn't the NBA alone disprove that theory?
Albert Einstein? 5'9"
NBA players get paid a lot of money to play their favorite game. They may not all be smart, but they are successful on some level!
Considering that young men suddenly given ridiculous amounts of money often do stupid things, I'm not sure I agree. Despite exceptions like Artest, the crime ratio for NBA players is probably a lot smaller than considerably shorter NFL players. Major league baseball players have had some pretty stupid incidents over the years. Some of the NBA big men over the years have been pretty sharp, Wilt, Russell, David Robinson are just a few of the NBA giants who come across as having a good head on their shoulders.