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The researchers also found evidence for what they call "inverted-U" behavior. That's the tendency of curiosity to be greatest at some mid-point between ignorance and wisdom--the peak of the inverted U. "The fact that curiosity increases with uncertainty (up to a point) suggests that a small amount of knowledge can pique curiosity and prime the hunger for knowledge, much as an olfactory or visual stimulus can prime a hunger for food," they concluded in a 2008 issue of Psychological Science.