2. Children
Whether it's Esther, the little orphan girl, or creepy Damien from The Omen, everyone knows that children in horror movies can only mean one thing - and that thing is terror. We should congratulate movies for being so clever that they have actually made us fear what is approximately 25% of the population. So what is it that makes children in movies so scary, then? Well, the typical child is sweet and innocent. Sure, they dribble on your furniture and don't always make it to the toilet in time, but in real life children are okay and mostly not creepy at all. But what happens when something so small and cute wants to kill you? Nobody expects a little girl with pigtails to be wielding a knife in your kitchen and that's what makes you look twice when you see a sweet child staring at you in the supermarket. You just don't know what they're thinking! I'm not saying all parents should assume that their children are maniacs, but... well, I am sort of saying that, I guess.