To respond to "cultural" conditioning, I think it's actually more inborn aversions. Animals have behavioral instincts based on particular movements (make certain moves around your cat and you will trigger a particular swipe or head movement reflex).
I think the problematic animals typically have movement patterns that trigger some kind of aversion response. Spiders don't move the same way as other animals do, and it's the only critter I typically have an issue with -- and I had the same creep-out watching that scene in Exorcist (or other movies) where she scuttles around like a spider.
I've watched some female friends who are afraid of mice, and it's the movement that triggers their scream reflex; i have no issues with mice, but the way mice dart around freaks them out. Some of that can be cultural, yes (it can be layered OVER a natural response); but I think at core there's still something about the darting movement that generates an automatic response.
And the other animals too that typically generate fear responses. Snakes and centipedes/bugs have typical natural aversive responses to those who are creeped out by them. None of them happen to bother me. And pretty much all other animals seem to be more "conscious caution" rather than some muscle-reflex fear response. (I don't freak at the sight of a bear, for example. But a bear can generate a conscious fear response because I know how strong they are, and I would be very wary.)
It's not that I think, "oh, it's a spider, gross I hate spiders, uggh, let's get scared." It's literally like touching a hot pan, and my hand jerks back / drops it, and then I think, "oh. The pan was hot. Boy, does my hand hurt."
I think these types of versions are also automatic reflexes. For some reason, regardless of any rationalization, I get an immediate "get away" response to spiders.
I'll note too I don't have the same reactions to all spiders. The bigger they are, though, the worse it is. Really tiny spiders don't bug me too much. It's the longer legs and when I can see how they move, where my skin just crawls immediately.
I saw a Wasp Spider in my garden a few weeks ago and did not feel at all like picking it up. I think it was an instinctual response to its having the danger signals - colour/pattern of wasps etc
Is that what they're called? I think I've heard them referred to as garden spiders or a black and yellow argiope.
They usually peppered the fields where I grew up, in the off-season from corn when the weeds would grow a few feet high. We would be running through the fields playing and plow almost right into them -- talk about freaking me out, lol. They were big, too... up to as big as my thumb now (in terms of total length).