Book explains why Halloween attractions make us “Scream”

This undated image provided by the publisher PublicAffairs shows the cover of "Scream: Chilling Adventures in the Science of Fear," a book by Margee Kerr, a sociologist who studies fear. The book documents Kerr's adventures around the world checking out extreme and scary attractions from roller coasters and haunted houses to the CN Tower EdgeWalk in Toronto. (PublicAffairs via AP)