Franciscus Bernardus Maria "Frans" de Waal, PhD (born 29 October 1948) is a Dutch primatologist and ethologist. He is the Charles Howard Candler professor of Primate Behavior in the Emory University psychology department inAtlanta, Georgia, and director of the Living Links Center at the Yerkes National Primate Research Center and author of numerous books including Chimpanzee Politics and Our Inner Ape. His research centers on primate social behavior, including conflict resolution, cooperation, inequity aversion, and food-sharing. He is a Member of the United States National Academy of Sciences and the Royal Netherlands Academy of Sciences.
De Waal was born in 's-Hertogenbosch. De Waal studied at the Dutch universities of Radboud University Nijmegen, University of Groningen, and Utrecht. In 1977, De Waal received his doctorate in biology from Utrecht University after training as a zoologist and ethologist with Professor Jan van Hooff, a well-known expert of emotional facial expressions in primates. His dissertation research concerned aggressive behavior and alliance formation in macaques.
In 1975, De Waal began a six-year project on the world's largest captive colony of chimpanzees at the Arnhem Zoo. The study resulted in many scientific papers, and resulted in publication of his first book, Chimpanzee Politics, in 1982. This book offered the first description of primate behavior explicitly in terms of planned social strategies. De Waal was first to introduce the thinking of Machiavelli to primatology, leading to the label "Machiavellian Intelligence" that later became associated with it. In his writings, De Waal has never shied away from attributing emotions and intentions to his primates, and as such his work inspired the field of primate cognitionthat, three decades later, flourishes around themes of cooperation, altruism, and fairness.
His early work also drew attention to deception and conflict resolution, nowadays two major areas of research. Initially, all of this was highly controversial. Thus, the label of "reconciliation", which De Waal introduced for reunions after fights, was questioned at first, but is now fully accepted with respect to animal behavior. Recently, De Waal's work has emphasized non-human animal empathy and even the origins of morality. His most widely cited paper,  written with his former student Stephanie Preston, concerns the evolutionary origin and neuroscience of empathy, not just in primates, but in mammals in general.
De Waal's name is also associated with Bonobo, the "make love – not war" primate that he has made popular. But even his Bonobo studies are secondary to the larger goal of understanding what binds primate societies together rather than how competition structures them.
Competition is not ignored in his work: the original focus of De Waal's research, before he was well known, was aggressive behavior and social dominance. Whereas his science focuses on the behavior of nonhuman primates (mostly chimpanzees, bonobos, macaques, and capuchin monkeys), his popular books have given De Waal worldwide visibility by relating the insights he has gained from monkey and ape behavior to human society. With his students, he has also worked on elephants, which are increasingly featured in his writings.