It's bad biology to argue against the existence of animal emotions. Scientific research in evolutionary biology, cognitive ethology and social neuroscience support the view that numerous and diverse animals have rich and deep emotional lives. Emotions have evolved as adaptations in numerous species and they serve as a social glue to bond animals with one another. Emotions also catalyze and regulate a wide variety of social encounters among friends and competitors and permit animals to protect themselves adaptively and flexibly using various behavior patterns in a wide variety of venues. Charles Darwin's well-accepted ideas about evolutionary continuity, that differences among species are differences in degree rather than kind, argue strongly for the presence of animal emotions, empathy, and even moral behavior. In practice, continuity allows us to connect the "evolutionary dots" among different species to highlight similarities in evolved traits including individual feelings and passions. What we have since learned about animal emotions and empathy fits in well with what we know about the lifestyle of different species—how complex their social interactions and social networks are. Emotions, empathy, and knowing right from wrong are keys to survival, without which animals—both human and nonhuman—would perish. That's how important they are. The borders between "them" (animals) and "us" are murky and permeable.

Studying animal emotions addresses a number of big questions concerning how science is conducted. Many skeptics feel that we are so uncertain about whether other animals have any sort of emotional life that they prefer to put off weighing in until we know more. For some, this really means waiting until we are absolutely sure. But science is never as certain as many would like it to be. Climate change researcher Henry Pollack says it well in his book Uncertain Science ...Uncertain World: "Because uncertainty never disappears, decisions about the future, big and small, must always be made in the absence of certainty. Waiting until uncertainty is eliminated is an implicit endorsement of the status quo, and often an excuse for maintaining it ... Uncertainty, far from being a barrier to progress, is actually a strong stimulus for, and an important ingredient of, creativity."

I often begin my lectures with the question: "Is there anyone in this audience who thinks that dogs don't have feelings—that they don't experience joy and sadness?" I've never had an enthusiastic response to this question, even in scientific gatherings, although on occasion a hand or two goes up slowly, usually halfway, as the person glances around to see if anyone is watching. But if I ask, "How many of you believe that dogs have feelings?" then almost every hand waves wildly and people smile and nod in vigorous agreement. Using behavior as our guide, by analogy we map the feelings of other beings onto our own emotional templates, and we do it very reliably.