Fear of the dark is a common fear or phobia among toddlers, children and, to a varying degree, adults. A fear of the dark does not always concern darkness itself; it can also be a fear of possible or imagined dangers concealed by darkness. Most toddlers and children outgrow it, but this fear persists for some with scotophobia and anxiety. When waking up or sleeping, these fears may intertwine with sighting sleep paralysis demons in some people.[1] Some degree of fear of the dark is natural, especially as a phase of child development.[2] Most observers report that fear of the dark rarely appears before the age of two years and roughly peaks around the development stage of four years of age.[3] When fear of the dark reaches a degree that is severe enough to be considered pathological, it is sometimes called scotophobia (from σκότος – "darkness"), or lygophobia (from λυγή – "twilight").
Some researchers, beginning with Sigmund Freud, consider the fear of the dark to be a manifestation of separation anxiety disorder.[4]
An alternate theory was posited in the 1960s, when scientists conducted experiments in a search for molecules responsible for memory. In one experiment, rats, normally nocturnal animals, were conditioned to fear the dark and a substance called "scotophobin" was supposedly extracted from the rats' brains; this substance was claimed to be responsible for remembering this fear. These findings were subsequently debunked.[5]
I once heard a child who was afraid of the darkness call out: 'Auntie, talk to me, I'm frightened.' 'But what good will that do? You can't see me?' To which the child replied: 'If someone talks, it gets lighter.'