It should come as no surprise to you that part of the reason we see what we see has to do with the fact that we are pattern-seeking organisms. In his second absolutely fascinating TEDTalk presentation (watch the first one about 'why people believe weird things'), Michael Shermer analyzes two specific types of pattern recognition problems the human mind is likely to commit: Type I (false positives) and Type II (false negatives).
Although one may find superstition incredibly infuriating, we must understand that its prevalence is at least partly explained by the fact that, in purely evolutionary terms, the tendency to find patterns, even when there aren't any, would have benefited our ancestors' chances for survival (although it would have also helped them develop all sorts of looney beliefs). The key, of course, is to find that delicate balance between radical skepticism vs radical gullibility: you don't want to be too close-minded to new valuable ideas, but you also don't want to be so open-minded that your brain falls out...
Understanding the difference between these two types of pattern-recognition mistakes, Shermer provides a simple conceptual framework to understand why so many people believe in so many weird things. As if all the scientific explanations weren't awesome enough, the presentation ends with a hilarious little experiment totally worth being shared in the Philosophy Monkey blog :)
If I were a psychology researcher looking for funding, I would totally contact Candid Camera to invest in my research :)