Mama's Last Hug opens with the moving farewell between Mama, a dying 59-year-old chimpanzee matriarch, and Jan Van Hoof, who was Frans de Waal's mentor and thesis advisor. The filmed event has since gone viral (over 9. 5 million views on YouTube), and so begins Frans de Waal's whirlwind tour of new ideas and new findings about animal emotions, based on his renowned studies of the social and emotional lives of chimpanzees, bonobos, and other primates. De Waal discusses facial expressions, animal sentience and consciousness, the emotional side of human politics, and the illusion of free will. He distinguishes between emotions and feelings, all the while emphasizing the continuity between our species and other species. And he makes the radical proposal that emotions are like organs: we haven't a single organ that other animals don't have, and the same is true for our emotions.