In 2006, a little-known movie entitled Idiocracy was released. The story starts in our present time, where an American soldier is ordered to be cryogenically frozen for one year. He is selected because all tests suggest he is an average Joe. After being frozen, he is forgotten for almost 500 years.
He is awakened to find that America has become a dystopian society and after some testing, it is discovered he is now the smartest man alive. The narrator explains that over the last several generations, the less educated tend to have lots of intimate relations, which resulted in more and more offspring just like them. On the other side, intelligent people tended to be reserved and had very few offspring. It was kind of a Darwin theory of evolution in reverse.