Kelley Armstrong

"People see patterns everywhere. It's in our nature to perceive vague stimuli as significant--a process called pareidolia. Arguably, we evolved to see things that aren't there as a survival mechanism."
"How can hallucinating help you survive?"
"Not exactly hallucinating, more like the brain guessing. Say you see what might be a tiger in the brush. Sometimes it' a tiger, sometimes not, but if your brain always insists it is a tiger, you're more inclined to run. Over time, you have a better chance of surviving and passing on that trait."