Twin Studies Guest: Nancy Segal, author, "Accidental Brothers: The Story of Twins Exchanged at Birth and the Power of Nature and Nurture," Professor, Psychology, and Director, Twin Studies Center, California State University, Fullerton We hear the story of two babies, each from a set of twins, who were switched at birth. The two pairs of mixed-up twins discovered the swap when they were 25 and now they're a band of four brothers. But the study of these twins, and many others separated at birth, has larger lessons on the impact of nature vs. nuture.  Raising Healthy Twins Guest: Joan Friedman, twin expert, psychologist, and author, “Twins in Session: Case Histories in Treating Twinship Issues”  There’s always been a mystique around the idea of twins. Have you ever wondered what it would be like to have an identical twin? Have you sometimes watched twins interacting and wondered, "Am I missing something?" "Are they speaking their own language?" Friedman says we should spend less energy romanticizing the special relationship between twins and focus instead on how well twins bond with their parents, just as we would with single babies.