Things heading in the opposite direction?
Evolution does not necessarily reward intelligence. With no natural predators to thin the herd, it began to simply reward those who reproduced the most:
From the 20th Century Fox movie, Idiocracy.
Plot Summary: In order to save some of their best men for the future when they may be desperately needed, the pentagon develops a special hibernation program. Naturally, a test subject is necessary in the beginning to help discover any limitations or to inspect for possible kinks in the system. The officers select Private Joe Bowers (Luke Wilson), one of their biggest under-achievers, as a guinea pig. For the female subject, they volunteer Rita (Maya Rudolph), a prostitute looking to have the criminal charges against her dropped. Of course, the experiment, which was only meant to last a year, doesn’t proceed according to plan. The primary officer in charge of the research gets busted for running an illegal prostitution ring. Largely due to the fact that he was one of very few people that knew about the test, Joe and Rita are soon completely forgotten about. The two awaken 1,000 years in the future to a world that has deteriorated immeasurably. Human beings have gotten so lazy, so dumbed-down, so entranced by mindless sensationalist entertainment that Joe is actually a genius in comparison. In fact, an IQ test shows that he is the smartest person alive. Aided by a lawyer named Frito (Dax Shepard), who ironically may be the dumbest person alive, Joe looks for a way back home, far away from a society that has difficulty deciding whether he is a possible savior or a potential threat. Link