I voted "it depends." In the UK spiders are mostly harmless to humans, and I don't worry about their presence unless they touch me, which does scare me a little bit, but not unduly. In Arkansas there are some rather dangerous spiders, and as I don't know much about how to recognise which are safe, common sense dictates that I'd best stay away from them all, and I feel significant fear when I'm confronted with any insect that's unknown to me. I've heard that fear of creepy-crawlies is natural, having once been a survival instinct in places where dangerous insects existed.