Well, not all are, but many are. So many in fact, that to me it seems to be an instinctive response. Because, for sure, it isn't rational. Spiders aren't dangerous in most of the world. The worst they can do is nip you. They're tiny. But there's just something about their little hairy bodies and long, sharp legs with the bendy ends that many people just can't stand. We often vary from being twitchy around them, to distinctly not liking them, to being terrified of them. To be honest it's like being afraid of a dust ball under your bed.
Human beings do have some real instinctive safeguards inbuilt, which have protected us back when our reasoning brains weren't what they are now. For instance we hate the smell of sulphur compounds, and feel sick at them. This is probably evolved to stop us eating rotting meat, since our guts aren't designed for it and it would kill us. We're also instinctively afraid of heights, and of other things that are common phobias, such as deep dark water. There is a theory that phobias are simply old things from evolution recurring. Our aversions to eating rotting meat, jumping off cliffs and swimming in filth are obvious, but what about spiders?
If fear of spiders is an instinctive response common to all human beings and only overcome by childhood or adult conditioning, or simple experience, where did it come from?
