A phobia is an extreme or irrational fear towards something. For example, people are known to have phobias of inanimate objects, such as pickles. Certain phobias, like the one I just mentioned, are completely irrational (unless someone is deathly allergic to pickles). Then there are more rational phobias, like a fear of flying. People have reasons to be afraid of flying. Plane crashes happen and recent terrorist attacks have increased the amount of people that have an irrational fear of flying. But when you look at statistics, a fear of flying is not rational at all. You're more likely to die from a bee sting than from flying, yet the same people who are afraid of flying will frolic around outside all summer long. Phobias do have something to teach us though. The pickle example is an exception, but according to preparedness we are evolutionarily predisposed to fear certain types of stimuli over others because at one point in time in human history they probably DID pose a very real threat, for example, poisonous spiders. Because of this phobias can also be considered evolutionary memories. I have a very big phobia of spiders. I have never been bitten by a poisonous spider, or even had a very traumatic experience with a spider. I was just born terrified of them. I do wonder whether these phobias will slowly dissipate, or at least if certain ones will. With modern medicine we can cure poisonous bites or stings, so will our phobias eventually die out in those particular areas?