Our guest is Frans de Waal, a prolific author who's also the C.H. Candler Professor Emeritus of Primate Behavior at Emory University and the former director of the Living Links Center at the Yerkes National Primate Research Center. He joins us to discuss his new book, "Different: Gender Through the Eyes of a Primatologist." It's a work that explores ongoing scientific questions like sex-versus-gender, men-versus-women, masculine-versus-feminine, and nature-versus-nurture, applying to each of these dichotomies the clear thinking and careful observation of a scientist who's been studying primates for 40+ years. Per The Washington Post, this book "adds an important evolutionary dimension to one of the most complex issues of our time.... The beauty of a book by Frans de Waal is that once you read it, you'll never look at your own species the same way again."