Scientists have determined that we come into this world with only two innate fears: the fear of falling and the fear of loud sounds. All other fears constitute learned behaviors, perhaps explaining why some people fear snakes and spiders and others do not. So the short answer is that being afraid of the dark is a learned, rather than innate, fear.
Researchers have observed that having a fear of falling is universal in animals and human babies, indicating that it is a survival instinct necessary for many species. And when you hear a loud sound, your “acoustic startle reflex” engages, and you will likely face a fight or flight decision. If the sound is loud enough, you typically duck. “That circuitry is innate,” explains Seth Norrholm, a neuroscientist at Emory University.
Nothing to fear here: