What separates your mind from an animal's? Maybe you think it's your ability to design tools, your sense of self, or your grasp of past and future; all traits that have helped us define ourselves as the preeminent species on Earth. But in recent decades, these claims have been eroded, or disproven outright, by a revolution in the study of animal cognition. Take the way octopuses use coconut shells as tools; elephants that classify humans by age, gender, and language; or Ayumu, the young male chimpanzee at Kyoto University whose photographic memory puts that of humans to shame. Based on research involving crows, dolphins, parrots, sheep, wasps, bats, whales, and of course chimpanzees and bonobos, Frans de Waal explores the scope and the depth of animal intelligence, revealing how we have grossly underestimated their abilities.