Our brains are designed to make sense of the onslaught of sensory stimulation and information that they get from the world by filtering and organizing. We have a tendency to focus on certain details and ignore others, to avoid being overwhelmed. And we habitually organize information into patterns, based on things we've seen or learned about before. That leads us to process what we hear, read or see in a way that reinforces what we think we already know. That phenomenon is called cognitive bias [source: Science Daily].
To make matters worse, some theorize that we also engage in selective exposure -- that is, we pick sources of information that tell us what we want to hear. Ohio State researchers, for example, found that when college students spent a few minutes reading news articles online, they selected ones that supported their already-held views 58 percent of the time [source: Hsu].
So, we're vulnerable to information that fits what we want to believe -- even if it's of dubious authenticity. That's probably why the infamous photograph of the Loch Ness monster, taken in 1934 [source: Nickell], was so convincing for many people. The silhouette resembled a long-necked dinosaur, which was something they had seen pictures of in natural history textbooks. And the idea that ancient creatures might have survived extinction already had surfaced in fiction such as Arthur Conan Doyle's 1912 novel "The Lost World," so it wasn't too much of a leap conceptually. It wasn't until 1994 that researchers got an elderly man who had been part of the hoax to reveal that the monster in the photo actually was a foot-high model, fashioned from a toy submarine [source: Associated Press].