PETER EARNEST worked in the Central Intelligence Agency for 36 years, including a quarter-century in the Agency's National Clandestine Service. He is the Executive Director of the International Spy Museum in Washington, D.C.

MARYANN KARINCH is the author of How to Spot a Liar, I Can Read You Like a Book, and How to Become an Expert on Anything in 2 Hours (978-0-8144-0992-3).