What do black cats, opening umbrellas indoors and the number 13 have in common? Well, they are all superstitions, that is, if you choose to believe in that sort of thing. But where do these beliefs come from, and why is it that we feel a little uneasy when we break "the rules"? As it turns out, many of these beliefs originate from religious practices that have died away, but continue to linger due to a cultural and societal tradition. To learn more about the origin of superstitions, click here.