In this episode, journalist Chip Walter, author of Thumbs, Toes and Tears, takes us on a tour of the physical traits that are unique to humans, with special attention to crying, the subject of his article in the current issue of Scientific American MIND. The University of Cambridge's Gordon Smith discusses the alarming lack of any randomized, controlled trials to determine the efficacy of parachutes. Plus we'll test your knowledge about some recent science in the news. Websites mentioned on this episode include www.sciammind.com; www.chipwalter.com; www.bmj.com.