Why Are People Afraid of the Dark?

OK I'll give you a scenario to think about. Lets say you're in a room with no lights on and there happens to be a killer in the room. He's looking for you and there is a chance that he might find you and theres a chance that he won't find you. Here is another scenario. Let's say you're still in the room but there are lights on and theres still a killer in the room. Since the lights are on theres no doubt about it, you are going to get killed. He doesn't need to find you, because he already has. In which of these scenarios would you be more scared? Probably the first.

Why is that? Well by human nature, people tend to be fearing of the unknown. I mean its kind of scary to be unsure of what is going to happen right? And it is ensuring to know whats going to happen. But don't you think it'd make more sense to be less scared in the first scenario than the second? Let me take the chance to elaborate on my theory. In the first scenario there is a chance that you will be found and a chance that you won't. That brings in the factor of optimism, knowing that theres a chance you will make it. The second scenario has no chance of survival. The dark is kind of like an invisible cloak. So turn off your lights and wear that invisible cloak. It shields you from all the harm in the world, and it saves you money on electricity. Good deal right? Right.

Now lets look into the human mind for a second. As I stated before by human nature, people fear the unknown. This is mainly because with the unknown, the outcome of the unknown can range from an infinite amount of possibilities of what the unknown may be. It could range from something mildly good to amazingly, spectacularly good or mildly bad to horribly, horrifically bad. Despite a mild good thing and a mild bad thing, both being mild, bad things tend to affect people much more than good psychologically. Getting a paper cut tends to put more stress on a person than the healing of said paper cut would relieve a person. That is just how the human mind works.