For a long time the Dutch American ethologist and zoologist Frans de Waal was told by senior scientists that studying emotions in animals was off-limits. But while working with chimpanzees and other primates in the Netherlands in the 1970s, he observed behaviors that seemed to match human expressions of emotions — and why not? Chimps are our closest animal relatives. In the last twenty-five years many scientists have caught up with de Waal’s observations, and the notion that animals have emotions is no longer so controversial. Over the course of his long career he has conducted studies showing that our fellow mammals exhibit jealousy, grief, forgiveness, and more. He believes there “are no uniquely human emotions.”