Fear of the darkIt is noteworthy, almost to the point of being cliché, that young children are much more afraid of the dark than adults. And that the reaction to such fear is a desire to crawl into bed with their parents.
There is probably a reason for this, linked to our evolution on the African plains. Leopards like to hunt on moonless nights, so that they can sneak up on their prey. They are masters of stealth; the pads on their feet are so sensitive that they can walk through even the driest, crunchiest grass without making a sound. Leopards may be sneaky, but they're not stupid; even if they can pounce on their prey in total surprise, they still think twice about attacking something as large as a fully grown human adult, particularly if said human adult is in a group. But a small child, left alone by itself, is another matter. Thus, any child that did not instinctively seek out adult caretakers while in the dark might not live long enough to grow up and have children of its own.
Fear of sudden loud noisesPsychological experiments have confirmed that there are two, and only two, fears that all humans are instinctively born with. They are the fear of falling, and the fear of sudden loud noises. Both of these will cause an immediate, involuntary reaction.Primal Fear), Stephen King says that the three kinds of fear are the "Gross-out", "Horror" and "Terror". These can be mapped fairly neatly onto the Known/Unknown Spectrum.
- Known Knowns: What King calls the "Gross-out." The danger is present and known. The awareness that blood, fire, sharp objects, high places, threatening behavior, etc. is present. A fresh corpse, a man wielding a knife or a bludgeon in a threatening manner, being trapped in a burning building, standing next to a pit full of spikes or deep enough to potentially kill - or just dark enough that one cannot tell just how deep it is. It's dangerous, but those present feel certain of its presence and extent. The choice of "fight or flight" can be made with full awareness.
- Known Unknowns: King fails to account for it; tropers would call it the "Jump Scare." Potential danger. The awareness that danger is approaching. Loud noises, uncertain footing. The scream of terrified prey or the snarl of the circling predator. The ground threatening to give way beneath one's feet. One is aware that danger approaches, but not when or where it will strike. One is uncertain whether to choose to fight or flee.
- Unknown Unknowns: What King calls "Horror." This is the unforeseen danger; Something that may or may not be a danger; something outside of our knowledge. The outside-context problem; the fear comes before the attack; all we know is that we don't know its nature or intent. The ghost/monster/alien/unknown-figure-in-the-dark doesn't need to do anything to inspire fear, just be obviously present and unfamiliar so witnesses cannot tell whether or not the danger can be confronted and thus are unwilling to decide whether to fight or flee.
- Unknown Knowns: This is what King calls "Terror." In his words; "(It's) when you come home and notice everything you own ha(s) been taken away and replaced by an exact substitute. It's when the lights go out and you feel something behind you, you hear it, you feel its breath against your ear, but when you turn around, there's nothing there..." It is nothing more and nothing less than the inability to assess the danger; the danger refuses to present itself for analysis or response — Morton's Fork — to prepare a response is to leave one's unguarded back open to attack. To flee in any direction could just as easily bring one closer to the danger than further. It is completely impossible to decide whether to fight or flee.
- False Assumptions: King fails to account for this as well, despite making perfect use of it in Cujo and The Shining; the danger coming from a source believed to be safe. One has already decided neither to fight or flee, and the opportunity to choose has passed, leaving one Alone with the Psycho.
In other words, all fear can be narrowed down to a single source — Danger! — but the degree of fear is not a direct correlation to the extent of the danger, but the extent to which the danger can be predicted. In other words, the less we can learn about the danger, the more frightened we are. Nothing Is Scarier.