The theory on animal behavior for most of history was this: people think and feel; other animals do not. It's only in recent years that there's been a sea change in the field of animal cognition, where, previously, there was almost no field at all. As The New York Times Magazine reports, animals studied in zoos seem to contain an emotional spectrum that could populate "a veritable Russian novel." Research into animal behavior is suddenly less about "Can this animal feel?" and more about "What is this animal feeling?" The answer could be a dolphin seeing itself in a mirror, an OCD brown bear, or a depressed red panda that'll break your heart.