The evolutionary purpose of itching

My feet sweat. A lot. I know, gross, but hey, it’s not like I chose it.

Suffice it to say that where there are sweaty feet, there is Athlete’s foot. For those who have never suffered from this, it is one of the most insanely itchy sensations you can imagine. When I get a bad case of it, the itchiness on top of my toes actually WAKES ME UP in the middle of the night.

Such was the case last night, so as I lay awake for two hours, scratching my toes raw, I wondered:

What possible evolutionary purpose can itchiness serve?

After all, any time we scratch an itch, it only seems to aggravate the problem underneath the itching, right? So in a way, the itching just makes everything worse.

So why have itchiness in the first place? Why hasn’t it been culled out of our sensory skill set over the past several million years.

I found what seems to be a reasonable answer HERE. Basically, the idea is that itchiness is a survival system gone haywire. If we have something like a mosquito or spider crawling on our skin, there’s an advantage to being able to feel it and swat it away.

But apparently itchiness is an aggravation of this highly sensitive system. So in a way, there’s no evolutionary purpose to itchiness itself, but it does point to a system that helps protect us from predators.

And if you’ve read this whole post without scratching yourself even once, you’re a better person than I. I’ve stopped half a dozen times to scratch just while typing it up.

About Christian Piatt

Christian Piatt is the creator and editor of BANNED QUESTIONS ABOUT THE BIBLE and BANNED QUESTIONS ABOUT JESUS. He co-created and co-edits the “WTF: Where’s the Faith?” young adult series with Chalice Press, and he has a memoir on faith, family and parenting being published in early 2012 called PREGMANCY: A Dad, a Little Dude and a Due Date.


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