American writer known for co-authoring The Book In the Beginning Was Sex (2010). After graduating with a degree in literature, Ryan traveled around the world. He spent twenty years in remote places, performing varied jobs, from salmon fishing in Alaska to teaching English to prostitutes in Bangkok to managing commercial real estate in Manhattan's Diamond District. Her doctoral thesis analyzed the prehistoric roots of human sexuality and was guided by psychologist Stanley Krippner, along with other committee members such as Sabrina Zirkel and Jürgen W. Kremer. Ryan's ideas about human sexuality appear regularly in publications ranging from Cosmopolitan to scientific journals, and he writes a popular blog for Psychology Today. Together with psychiatrist Cacilda Jetha, he wrote the bestseller In the Beginning It Was Sex, which challenges many of the central assumptions of evolutionary psychology, has won several prestigious awards from organizations of sex researchers and therapists, and has been translated into more than ten languages. In 2013, Ryan gave a TED talk titled Are We Designed to Be Sexual Omnivores? In addition, he collaborates with Psychology Today and regularly hosts a popular podcast called Tangentially Speaking with Dr. Christopher Ryan.