This is the most common animal-related phobia in Britain, even though there are no dangerous spiders in this country, whereas people do get injured by dogs and cattle. No one really knows why spider phobia is so common. My guess is that the tendency to fear spiders is a “racial memory,” that is, a memory of the entire human race, inherited from very long ago when our ancestors lived in areas where poisonous spiders did exist. However this is just a tendency, because most people are not in fact afraid of spiders.
You can read HERE about how phobias are generally created.
But it’s often not clear why the full-on spider phobia occurs in certain people. Perhaps some of us inherit a stronger version of the racial memory, just as in a family some children are darker or lighter than others. Or perhaps arachnophobia, like other phobias, results from a traumatic event in childhood. Now of course the spider itself cannot really traumatise a child. It cannot sting you like a bee or wasp, or even make an annoying sound like a fly. But possibly a small baby could be traumatised by encountering a spider at the same time as sensing the anxiety and stress of adults due to some other cause. These are just theories though, as we have no real way of knowing what a baby might have experienced at a very early age before he has the words to tell us. Fortunately a phobia can be treated even when we don’t know what originally caused it.
Interestingly, I find that some people with arachnophobia are less scared of tarantulas (the extremely large furry spiders) than of the normal spiders you might find in your home. I suppose this could be because the tarantula is so big that it doesn’t feel like a spider. Or it may be because the ordinary house spiders move much faster.
People who fear spiders are especially apprehensive in the autumn because spiders tend to come into the house at that time due to the weather getting colder. The main problem they experience is embarrassment at having to get someone else to remove the spider. Of course they know that the spider is entirely harmless but this makes them feel worse, not better, because it makes them feel stupid or ridiculous. In extreme cases I have known people to remain outside their home, or locked in a bedroom, for hours, until their partner or housemate comes home and can deal with the spider.
While terrified due to being in the presence of a spider, people with arachnophobia can sometimes get very strange ideas which they would never have at other times. For instance they may become convinced that the spider knows how scared they are and is taunting them maliciously by moving towards them!
You can read HERE about the main elements of hypnotic treatment for phobia. Many people avoid therapy for arachnophobia because they imagine the therapist will suddenly open a huge box full of spiders. This technique is called “flooding” but it would never be used by any competent therapist as it would likely make the client worse. In effective phobia treatment the therapist should never spring any surprise on the client which they’re not yet ready to deal with.