Robert Seyfarth and Dorothy Cheney draw on their decades-long pioneering research on monkeys and baboons in the wild to show how primates use vocalizations to modulate social dynamics. Their argument serves as a jumping-off point for responses by John McWhorter, Ljiljana Progovac, Jennifer E. Arnold, Christopher I. Petkov and Benjamin Wilson, and Peter Godfrey-Smith, each of whom draw on their respective expertise in linguistics, neuroscience, philosophy, and psychology. "There is no doubt in my mind that this book will attract attention and will be widely referred to." - Cedric Boeckx.