The Evolution of Why We’re Afraid of the Dark

Nyctophobia is defined as an intense, irrational fear of darkness or night. People with this phobia really don’t fear anything particular in the darkness but are afraid of the darkness itself, the apparent nothingness, the mystery that it holds. What could be out there, rather than what actually is, compounds the irrationality one’s mind is conjuring.

This phobia is an evolutionary adaptation that’s hardwired into human brains as a means of protecting their hosts from dangers that lurk in the dark. Our earliest ancestors were designed to fight or flee from a threat. These days, although we’ve retained the fight or flight reaction, it’s more psychological than physical and keeps us up when we want sleep.

Most of us can probably relate to the anxiety that builds during insomnia. Lying in a dark, quiet room, one’s mind races through a minefield of sinister thoughts — problems at work, the news story about the home break-in... “Did I remember to lock the front door?”... Meanwhile, the tossing and turning seem like they will continue all night.

Although humans are basically blind in the dark, other senses are amplified. However, a heightened sense of hearing, for example, can also exacerbate feelings of anxiety and intensify our fear to an almost primal level. Extreme fear can cause physical reactions such as shortness of breath and goosebumps, which can give the eerie perception of being touched.

Our earliest ancestors were extremely vulnerable living out in the wild. Their only defense were fire and whatever crude weapons they created. They didn’t generally have the speed or agility needed to fight off a large predator. So, just as our ability to reason is our biggest defense against our darkness phobia, it has also ultimately saved our species.