I had an interesting insight into the way my mind works tonight.
A cave cricket got into my mother's house this evening. You know, those fairly creepy crickets that scare the daylights out of most people because of their resemblance to spiders. However, cave crickets don't bother me at all, and I'm quite the arachnophobe. Ask any of my friends or family who have seen me climbing onto tables and counters and screaming as a spider approaches me. I really wish I was exaggerating.
I examined this cave cricket, let's call him Gary, for some time, and I took the opportunity to compare him to my deepest nightmares to see what exactly it was that kept my mind from freaking out at his spider-like countenance as opposed to an actual spider. To start with, I've know for some time that the number of legs doesn't matter. Scorpions also have eight legs, and they've never bothered me.
The first thing I noticed was that I could clearly see Gary's eyes, which led me to the realization that it freaks me out that I can't see spiders' eyes without getting close to them. You can tell which way I spider is looking by the build of its body, but you can't see any eyes! It's absolutely terrifying. I'm no psychologist, but my theory is that my brain is more ready and willing to anthropomorphize something with a clear face. Spiders, lacking a clear face, are therefore alien and lie too far on the wrong side of the uncanny valley.
Secondly, I gained a good bit of insight by watching Gary move. When he hopped about in a cricket-like manner, everything was fine and dandy. But for the brief period of time that he crawled in a rather more spider-like fashion, my brain started raising red flags, and I felt myself beginning to freak out. It would seem that I'm fine with hopping and scuttling and running and crawling, but as soon as I see that freakish, sinuous, undulating crawl with which spiders typically move, it bugs me. Pun intended, I'm sorry. And, come to think of it, jumping spiders have never bothered me as much as their crawling kin.
It's possible that there are more things about spiders which freak me out, but for now, I feel comfortable that I've narrowed the main reasons down to the two above. I suspect the lack of a clear face is something that bothers most people, but it's possible the fear of their movement is a more unique response. Maybe my brain has just learned to associate that sort of movement with spiders, and thus reacts as though there were a spider present, even when not.
Fun times! Knowledge is power, and maybe as I continue to figure my brain out, I can get more use out of it.