4. Idiocracy (2006)

Idiocracy serves as the answer to a question that no one asked – what would happen if everyone on Earth got collectively more stupid with time? It follows the entirely average Joe (Luke Wilson) when he wakes up 500 years in the future only to learn that everyone is incredibly dumb. Suddenly, he’s the smartest man on Earth, and he’s needed to solve all manner of problems using the power of common sense.
The thing is, it’s whole plot revolves around one key idea: that stupid people had too many children, and the population got increasingly less intelligent as a result. There’s a pretty obvious issue with that, and it’s one that many people have called out since the film’s release. Basically, Idiocracy inadvertently attempts to justify eugenics.
In essence, it’s a film that asserts certain people shouldn’t have children, because they’ll pass down undesirable traits. The film’s entire story leans heavily into that idea, and though it’s a comedic social satire, it’s not easy to laugh knowing the argument the film is making. Though it may not have been intended, it’s still one of the most harmful and terrible hidden messages that any movie has ever put out into the world.