Jesse Bering is the author of The Belief Instinct and Why Is the Penis Shaped Like That? (July 2012). He is a frequent contributor to Slate and writes the "Bering in Mind" column for scientificamerican.com. His next book will be on the curiously scandalous science of human sexuality. Follow him at www.jessebering.com, on Twitter @JesseBering, or try adding him on Facebook.