Primatologists Frans de Waal has published a number of books on chimpanzee behaviour, including Peacemaking Among Primates. In The Ape and The Sushi Master the author continues his explorations of human and primate culture in order to arrive at a better understanding of the roots of human behaviour. De Waal's study examines whether animals learn from one another and have what he defines as culture, or whether their actions are purely based on genetics and instinct.