John Carpenter said this quote

Monsters in movies are us, always us, one way or the other. They’re us with hats on. The zombies in George Romero’s movies are us. They’re hungry. Monsters are us, the dangerous parts of us. The part that wants to destroy. The part of us with the reptile brain. The part of us that’s vicious and cruel. We express these in our stories as these monsters out there.