My kids are both scared of the dark. Their dad thinks this is something that we should discourage. I disagree. I'm pretty sure our custody agreement indicates I'm in charge of all decisions regarding phobias. Because of all my experience in that area. I'll have to check the fine print.
I support my kids being afraid of the dark. I'm afraid of the dark. You know why?
BECAUSE YOU CAN'T SEE IN THE DARK.
What kind of moron would not be afraid of a situation in which they can't see? It's our main means of, like, knowing stuff. I'm not saying I think that monsters and serial killers materialize whenever the lights go out (they're already there), but I could bang my shin or something! That's scary, too!
I know there are people that would argue human beings no longer have instincts, but I think fear of the dark is proof that we do. Because almost all kids are afraid of the dark, and all the intelligent adults are, too. Dr. Spencer Reid is afraid of the dark. So, FACT.
Back when we were cavemen or whatever, you know what I bet happened if we were too stupid to be afraid of the dark? We'd go out clubbing (get it? Because we carried clubs... yeah, I kinda stole that from Bo Burnham) and the other animals, who ALL have better night vision than us would kill and eat us. All the genetically and mentally inferior unfittest types got weeded out by evolution long ago, so why do so many people want to be like the worst of the Neanderthals?
I know what you're thinking: but most of us don't live among the leopards and lions anymore, right? That's true. I can't argue with that. But my reasoning still totally applies if you're camping (because bears) or playing dark tag (because shins) or trapped in a serial killer's basement (because Silence of the Lambs, as previously discussed).
Anyhow, what I'm saying is maybe you don't have to crap your pants every time the power goes out, but why would you not prefer to be able to see? It's just the more intelligent thing to do. Using a night light doesn't make you a wuss--it makes you smarter than some tool who thinks it would be better to not be able to see.
You know who first started the idea that fear of the dark wasn't just a clever tool for survival? Freud. I think Freud had some crazy ideas (quite the revelation there, huh?) but this is one of his craziest. Something about separation anxiety, he says, is what causes fear of the darkness. Yeah, you're right--I DO get anxious when I'm separated from my ability to SEE THINGS. Sometimes a self-preservation instinct is just a self-preservation instinct, Siggy.
I'd like to take a moment here for this incredibly hilarious movie produced in 1953 by Encyclopaedia Britannica Films (I guess before encyclopaedias became irrelevant, they used to make informative videos?) about the fear of the dark. I offer it not as evidence but as a comedic break:
(That video is public domain, but I feel like I should link to my source, so it's here at Archive.org, which is just a treasure trove of unintentional hilarity and, to be fair, some pretty unmockably awesome stuff as well.)
So to sum up, if your heart pounds when it's so dark that you can't see your sweaty palm held in front of your face, then that's the intelligent part of your brain telling you to turn a damn light on. Or to stay still so you don't bump your shin or get mauled by a bear. That's SMART.
Honestly, though, it won't help you with the serial killer thing. Those suckers are nothing if not adaptable.
BONUS for the wordies: fear of the dark is called nyctophobia. But I refuse to call it that because phobias, by definition, are irrational, and I think we've clearly established that fear of the dark is the most rational thing one could possibly feel.