Animal Sentience and the Evolution of Emotion

story by Tracy Basile

Are some birds shy? Can a dolphin recognize himself in a mirror? Do elephants mourn their dead? Will a bat perform random acts of kindness? One hundred years ago, if a well-educated man of Western culture answered "yes" to any of these questions, he would have likely been locked away in an insane asylum. Even 50 years ago, it was rare to find any scientific studies that examined the emotional lives or the intelligence of animals. Such a huge omission is no accident.

Despite Charles Darwin's boldness and brilliance in the mid-1800s, animals have largely been viewed in European and American societies as automata, creatures of instinct, from simple protozoa to our closest relatives the chimpanzees. In the 20th century, renowned primatologist Dr. Jane Goodall broke new ground by recognizing that the chimps of Gombe were individuals with rich emotional lives. She and her colleagues started to look at animals in a new way—in their natural environments. Their pursuits gave rise to a new field of science known as ethology.

Other scientists have followed Goodall's example in dozens of fields, and in the last few decades, they have unearthed an amazing assortment of information about the inner lives of animals. So much research on this topic exists today that it is virtually impossible to refute that animals, in varying degrees, are sentient, use and make tools, teach their young, imitate, possess language, have long-term memory and experience emotions.

While studies in animal intelligence are rife with debate, sentience is fairly straightforward by comparison. It simply means being conscious, having the capacity to perceive through the senses. Often, it implies the capacity to suffer. "To be sentient is to be aware. One of the ways we are aware is pain," explains Dr. Roger Fouts, a professor of psychology at Central Washington University, an Animal Welfare Institute (AWI) board member and a co-director of the Chimpanzee and Human Communications Institute. "Sentience is a very useful trait to have in adaptation and survival," he says, adding that it is "far too complex to have popped up in our species without a long history of evolutionary development."

Barefoot in the Grass

Fouts is a pioneer of communicating with chimpanzees using sign language. In his book, Next of Kin: What Chimpanzees Have Taught Me About Who We Are," he depicts his 30+ year friendship with the chimpanzee Washoe and her family. The most moving passage in the book is when Washoe, Dar, Tatu, Loulis and Moja are released into a large outdoor enclosure and experience the sun on their backs and the grass under their feet for the first time in their lives. In a description spanning three pages, he details their reactions, including loud pant-hooting, running leaps off the deck, excitement, trepidation, joy and lots of hugs. "For weeks Moja and Tatu refused to come inside, even for meals. We had to beg and cajole to get them to eat. They spent so much time in the sun that their pale skin turned bright red. But Moja and Tatu didn't seem to mind being sunburned. They lived for the sun. By August, only three months after the move, Moja and Tatu were not only tan, they were physically and psychologically transformed," he wrote. Certainly enjoying the warmth of the sun or the cool grass upon their feet is part of being sentient. Without the ability to perceive these sensations, Moja and Tatu would not have responded so completely—emotionally, psychologically and physically—to these new surroundings.

A Change in Perception

New studies in animal sentience show that sheep can remember faces for up to two years, prairie dogs speak their own language, octopi disguise themselves by walking on two legs in order to escape predators, cows use tools and pigs can be devious and misleading to obtain food. But what does all this research add up to? And what does it imply about how animals should be treated in experimental laboratories, circuses, zoos, factory farms or slaughterhouses? Why is it that as scientists reveal one marvelous discovery after another, much of mainstream media treats these results as amusing trivia? At the very least, shouldn't animal sentience be taken seriously? As we enter the 21st century, the ramifications are huge. A shift in perception is desperately needed.

A landmark conference was held last month in London with the hopes of creating just this kind of sea change. Billed as "From Darwin to Dawkins: The Science and Implications of Animal Sentience," and sponsored by Compassion in World Farming Trust of the United Kingdom, the two-day event drew crowds of more than 600 participants from approximately 50 countries. It was the first time a conference devoted to animal sentience was staged on such a large and international scale. Dr. Goodall delivered a wonderful keynote speech; other speakers included eminent scientists and leading professors in ethology, agriculture, conservation, government policy, law, philosophy and ethics. Its purpose, according to Joyce D'Silva, CEO of the trust, was to "place animal sentience firmly on the global agenda." Marlene Halverson, AWI's farm animal economic advisor, was in attendance.

At the conference, Dr. Marion Dawkins (who is not related to Richard Dawkins, the famous ethologist referenced in the conference's title), a professor of animal behavior in the Department of Zoology at the University of Oxford, stressed the importance of thinking of animal welfare not simply in terms of what humans would like for animals, but in terms of what the animals would like for themselves.

Dr. Donald Broom, a professor of animal welfare at the University of Cambridge, enlightened listeners with his discussion of collaboration, altruism and mutual aid in animals. He explained that even unrelated individuals take care not to harm each other, noting that in herds of longhorn cattle, eye injuries are rare, despite the proximity of horns to other cows' faces. This is just one example of how big animals and animals with sharp horns move carefully around each other. It was once thought that only humans possess these noble traits. Broom made it clear in his talk that animal societies could not have survived without them.

Why Sentience Matters

There are huge obstacles in applying the knowledge we now know about animal sentience to the real world. The reason for this has to do with coming to terms with the inhumanity of the Western world. Many people today are, as Fouts puts it, "afraid to embrace the Darwinian realities of continuity."

Perhaps the word "sentience" covers too vast a territory, and this unfortunate fact has led to more confusion than clarity. On one end of the spectrum, the concept is as simple as a tulip turning to face the morning sun. On the other end, sentience is as complex as a young, healthy chimpanzee dying of a broken heart only a few weeks after the death of his mother. Or the courtship of two right whales.

Dawkins told participants at the London conference that even today, science does not know how the brain gives rise to the incredible richness of subjective experience. Indeed, cutting-edge research involving the study of neurochemicals, opiates and hormones indicates our emotions actually take form in our bodies. Consider the many pharmaceutical pills now available to relieve a person's anxiety and depression. The point is this: if emotions reside in our bodies, then they must reside in animals' bodies, too. To paraphrase Charles Darwin, the difference is one of degree, not one of kind.

The debate over animal sentience is curiously nonexistent in indigenous cultures where human survival is intricately woven with the lives of animals. Wasn't it sentience that sent the animals and indigenous people of Southeast Asia fleeing inland before December's devastating tsunami hit their shores? What else could it have been?

Chickasaw novelist and poet Linda Hogen says it best in her essay, First People; "For us, the animals are understood to be our equals. They are still our teachers. They are our helpers and healers. They have been our guardians and we have been theirs," she wrote. "We have deep obligations to them. Without the other animals, we are made less."

Sheep can recognize the faces of at least 10 people and 50 other sheep. When isolated from their flock, they experience stress, but being shown pictures of familiar sheep faces reduces their feelings of anxiety. They can also form deep friendships.

Elephants make graves by breaking branches to cover their dead. They also mourn.

Cows can recognize familiar faces, take pleasure in solving problems and form long-lasting and co-operative partnerships. Cows can also make tools; one heifer bent a piece of wire to create a hook that allowed her to scrape food from the bottom of a jar.

Wood mice build their own signposts using sticks and stones to mark sites where food is abundant, or to signal short-cuts back to their burrows.

Gibbons take care of their elderly. They move through forests hand over hand and will only go as fast as the slowest member of the group.

Chickens in pain will choose food laced with morphine, while healthy chickens do not. Also, when mother hens are given a choice of two foods, one toxic and the other safe, they will choose the non-toxic food. They teach their young chicks to avoid the toxic food as well.

Bats perform altruistic deeds. Father bats "babysit" and care for young bats who are not their offspring while mothers are out hunting.

Wild buffalo care for the weakest members of their herd by allowing only the strongest bulls to be trailblazers when foraging in deep snow.