YUK! That can mean many things including "there's a spider in my hair!" but what exactly IS that feeling?
I started thinking about this when I was typing some text at work and a spider fell off the roof and landed right in front of me. I wouldn't even have noticed the spider if not for the sound it made as gravity forced it to collide head-first with my desk, so that must have hurt!
When I looked down and realized that there was a spider looking at my arm as if it was a suitable surface to climb on to, I immediately moved back (there's a reason why these chairs have wheels!) turned pale and prepared to run away screaming like a little girl... of course I didn't do that, I just acted as if it didn't bother me at all because as we all know, real men aren't afraid of spiders!
Now, although people's reactions differ, what they feel is usually quite similar. Whether we're talking about spiders, centipedes, cockroaches or caterpillars, people "Yuk" to pretty much the same stuff.
But let's keep with the spider theme! So what is this discomfort that urges us to avoid such a tiny little creature? There are two questions here, what and why. What exactly am I reacting to in a spider and what purpose does such a feeling serve, and it's the first that popped up in my mind during this spider incident.
So what is that visual stimulae that makes us "yuk"? I'll be claiming that it's not really the aspect or shape of the spider, but rather what we anticipate is the experience of directly interacting with it. I got this idea from the great psychologist James Gibson (1979), he made this claim that our perception evolved for action and he introduced this concept of affordances. What this means in practice is that when we see a chair, we are not just seeing the angles, the materials, the colors, and so on. We're mainly seeing that the chair allows us to sit on it, or to fend off an attacker with it, or to stand on it to change a light bulb. So our visual perception of this object is not just it's brute graphical representation, it's actually much more about what you can do with it (or what it can do to you) than about how good it looks.
I found this idea very interesting and I've realized that most of this "yuk factor" regarding bugs isn't caused specifically by their shape/colors as we'd intuitively say, but instead it's caused by our overall perception of them which includes an anticipation of all possible direct interactions with such a creature, like the thought of having one crawling on your skin, the thought of having one in your mouth and all sorts of possible kinds of contact that would be highly undesirable.
This makes sense and relates very well with my personal experiences with spiders. If it was just about it's shape then all I had to do was to close my eyes but we know that's not true. Our awareness of it's presence nearby will still urge us to do something and make sure no direct contact is possible (ruthlessly taking it's life usually does the trick).
So if you think that the spider is an ugly creature that should be kept at distance, know that the problem is within yourself, not in the poor little spider! Strictly aesthetically speaking, a spider can be regarded as having a geometrically and functionally very beautiful body plan... right?