What Do We Really Know About Animals’ Emotions?

Frans de Waal on What We May Share With Other Species

By  Frans de Waal

Watching behavior comes naturally to me, so much so that I may be overdoing it. I didn’t realize this until I came home one day to tell my mother about a scene on a regional bus. I must have been 12. A boy and girl had been kissing in the gross way that I couldn’t relate to but that is typical of teenagers, with open mouths moistly clamped onto each other. This by itself was nothing special, but then I noticed the girl afterward chewing gum, whereas before the kiss I had seen only the boy chewing. I was puzzled but figured it out—it was like the law of communicating vessels. When I told my mom, however, she was less than thrilled. With a troubled expression, she told me to stop paying such close attention to people, saying it was not a very nice thing to do.

Observation is now my profession. But don’t expect me to notice the color of a dress or whether a man wears a hairpiece—those things don’t interest me in the least. Instead, I focus on emotional expressions, body language, and social dynamics. These are so similar between humans and other primates that my skill applies equally to both, although my work mostly concerns the latter. As a student, I had an office overlooking a zoo colony of chimpanzees, and as a scientist at the Yerkes National Primate Research Center, near Atlanta, Georgia, I have had a similar situation for the last 25 years.

My chimps live outdoors at a field station and occasionally get into upheavals that cause such a ruckus that we rush to the window to take in the spectacle. What most people will see as a chaotic melee of 20 hairy beasts running about hollering and screaming is in fact a highly ordered society. We recognize every ape by face, even just by voice, and know what to expect. Without pattern recognition, observation remains unfocused and random. It would be like watching a sport that you’ve never played and don’t know much about. You basically see nothing. This is why I can’t stand American television coverage of international soccer matches: most sports narrators came late to the game and fail to grasp its fundamental strategies. They have eyes for the ball only and keep on blabbing during the most pivotal moments. This is what happens when we lack pattern recognition.

Looking beyond the central scene is key. If one male chimpanzee intimidates another by throwing rocks or charging closely past the other, you need to deliberately take your eyes off them to check the periphery, where new developments arise. I call it holistic observation: considering the wider context. That the threatened male’s best buddy is asleep in a corner doesn’t mean we can ignore him. As soon as he wakes up and walks toward the scene, the whole colony knows things are about to change. A female gives a loud hoot to announce the move, while mothers press their youngest offspring close.

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And after the commotion has died down, you don’t just turn away. You keep your eyes on the main actors—they aren’t finished yet. Of the thousands of reconciliations I’ve witnessed, one of the first took me by surprise. Shortly after a confrontation, two male rivals walked upright, on two legs, toward each other, fully pilo-erect—meaning their hair was standing on end, making them look twice their regular size. Their eye contact looked so fierce, I expected a revival of the hostilities. But when they got close to each other, one of them suddenly turned around and presented his behind. The other responded by grooming closely around the anus of the first male, uttering loud lip-smacks and tooth-clacks to indicate his dedication to the task. Since the first male wanted to do the same, they ended up in an awkward 69 position, which allowed each of them to groom the other’s behind at the same time. Soon thereafter they relaxed and turned around to groom each other’s faces. Peace was restored.

We’re masters of fake happiness, suppressed fear, and misguided love.

The initial grooming location may seem odd, but remember that English (as well as many other languages) has expressions such as brown-nosing and ass-licking. I’m sure there is a good reason. Among humans, intense fear may cause vomiting and diarrhea—we say we “crap our pants” when we’re frightened. That’s also a common occurrence in apes, minus the pants. Bodily exits yield critical information. Long after a skirmish has ended, you may see a male chimpanzee casually stroll to the precise location in the grass where his rival had been sitting, only to bend down and take a sniff.

Although vision is about as dominant a sense in chimpanzees as it is in us, smell remains critically important. In our species, too, as covert filming has demonstrated, after we shake hands with another person, especially someone of the same sex, we often scent our own hand. We lift it casually close to our face to gather a chemical whiff that informs us about the other’s disposition. We do so unconsciously, as we do so many things that resemble the behavior of other primates. Nevertheless, we like to see ourselves as rational actors who know what we’re doing, while we depict other species as automatons. It’s really not that simple.

We are constantly in touch with our feelings, but the tricky part is that our emotions and our feelings are not the same. We tend to conflate them, but feelings are internal subjective states that, strictly speaking, are known only to those who have them. I know my own feelings, but I don’t know yours, except for what you tell me about them. We communicate about our feelings by language. Emotions, on the other hand, are bodily and mental states—from anger and fear to sexual desire and affection and seeking the upper hand—that drive behavior. Triggered by certain stimuli and accompanied by behavioral changes, emotions are detectable on the outside in facial expression, skin color, vocal timbre, gestures, odor, and so on. Only when the person experiencing these changes becomes aware of them do they become feelings, which are conscious experiences. We show our emotions, but we talk about our feelings.

Take reconciliation, or a friendly reunion following a confrontation. Reconciliation is a measurable emotional interaction: to detect it, all you, as an observer, need is some patience to see what happens between former antagonists. But the feelings that accompany a reconciliation—contrition, forgiveness, relief—are knowable only to those who experience them. You may suspect that others have the same feelings as you, but you can’t be sure even with respect to members of your own species. Someone may claim they have forgiven another person, for example, but can we trust this information? All too often, despite what they have told us, they bring up the affront in question on the first occasion that arises. We know our own inner states imperfectly and often mislead both ourselves and those around us. We’re masters of fake happiness, suppressed fear, and misguided love. This is why I’m pleased to work with nonlinguistic creatures. I’m forced to guess their feelings, but at least they never lead me astray by what they tell me about themselves.

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The study of human psychology usually relies on the use of questionnaires, which are heavy on self-reported feelings and light on actual behavior. But I favor the reverse. We need more observations of actual human social affairs. As a simple example, let me take you to a large conference in Italy, which I attended many years ago as a budding scientist. Being there to speak about how primates resolve conflicts, I hadn’t expected to see a perfect human example on display. A certain scientist was acting up in a way that I had never seen before and rarely have since. It must have been the combination of him being famous and being a native English speaker. At international meetings, Americans and Brits often mistake the extraordinary privilege of being able to speak in their mother tongue for intellectual superiority. Because no one is going to disagree with them in broken English, they are rarely disabused of this notion.

There was a whole program of lectures, and after every one, our famous English-speaking scientist jumped out of his seat in the front row to help us understand the work. Just as one Italian speaker finished presenting her work, for example, and even as the applause for her lingered, this scientist rose from his seat, climbed to the podium, took the speaker’s mike, and literally said, “What she actually meant to say . . .” I don’t remember the topic anymore, but the Italian speaker pulled a face. It was hard to miss this man’s cockiness and disrespect for her—nowadays we’d call it “mansplaining.”

Most of the audience members had been listening through a translation service—in fact, their delayed linguistic connection may have helped them see through his behavior, in the same way that we’re better at reading body language in a televised debate when the sound is turned off. They began to hiss and boo.

The expression of surprise on the face of our famous scientist showed how much he had misjudged the reception of his power grab. Until then, he’d thought it was going swimmingly. Flustered and perhaps humiliated, he hastily stepped down from the podium.

Anyone who claims to know what animals feel doesn’t have science on their side. It remains conjecture.

I kept my eyes on him and on the Italian speaker as they sat in the audience. Within fifteen minutes, he approached her and offered her his translation device, since she didn’t have one. She politely accepted (perhaps without actually needing one), which counts as an implicit peace offer. I say “implicit” because there were no signs that they mentioned the previous awkward moment. Humans often signal good intentions after a confrontation (a smile, a compliment) and leave it at that. I couldn’t follow what they were saying, but a third party told me that after all lectures were over, the scientist approached the speaker a second time and literally told her, “I have made a complete ass of myself.” This admirable bit of self-knowledge came close to an explicit reconciliation.

Despite the ubiquity of human conflict resolution, and its fascinating unfolding at the conference, my own lecture got a mixed reception. I had only just begun my studies, and science was not yet ready for the idea that other species perform reconciliations. I don’t think anyone doubted my observations—I provided lots of data and photographs to make my case—but they simply didn’t know what to make of them. At the time, theories about animal conflict focused on winning and losing. Winning is good, losing is bad, and all that matters is who gets the resources. In the 1970s, science viewed animals as Hobbesian: violent, competitive, selfish, and never genuinely kind. My emphasis on peacemaking made no sense. In addition, the term sounded emotional, which was not well regarded. Some colleagues took a patronizing approach, explaining that I had fallen for a romantic notion that didn’t belong in science. I was still very young, and they lectured me that everything in nature revolves around survival and reproduction, and that no organism will get very far with peacemaking. Compromise is for the weak. Even if chimps showed such behavior, they said, it’s doubtful they actually needed it. And surely no other species ever did the same. I was studying a fluke.

Several decades and hundreds of studies later, we know that reconciliation is in fact common and widespread. It occurs in all social mammals, from rats and dolphins to wolves and elephants, and also in birds. The behavior serves relationship repair, so much so that if nowadays we discovered a social mammal that didn’t reconcile after fights, we’d be surprised. We’d wonder how they kept their society together. But at the time I didn’t know this and politely listened to all the free advice. It didn’t change my mind, though, because for me observation trumps any theory. What animals do in real life always has priority over preconceived notions about how they ought to behave. When you are a born observer, this is what you get: an inductive approach to science.

Similarly, if you observe, as Charles Darwin famously did in The Expression of the Emotions in Man and Animals, that other primates employ human-like facial expressions in emotionally charged situations, you cannot get around similarities in their inner lives. They bare their teeth in a grin, they produce hoarse chuckling sounds when tickled, and they pout their lips when frustrated. This automatically becomes the starting point of your theories. You may hold whatever view you like about animal emotions or the absence thereof, but you will have to come up with a framework in which it makes sense that humans and other primates communicate their reactions and intentions via the same facial musculature. Darwin naturally did so by assuming emotional continuity between humans and other species.

Nevertheless, there is a world of difference between behavior that expresses emotions and the conscious or unconscious experience of those states. Anyone who claims to know what animals feel doesn’t have science on their side. It remains conjecture. This is not necessarily bad, and I’m all for assuming that species related to us have related feelings, but we should not overlook the leap of faith that it asks us to take. Even when I tell you that Mama’s Last Hug was an embrace between an old chimpanzee and an old professor a few days before her death, I cannot include her feelings in my description. The familiar behavior as well as its poignant context do suggest them, yet they remain inaccessible. This uncertainty has always vexed students of the emotions and is the reason the field is often considered murky and messy.

Science doesn’t like imprecision, which is why, when it comes to animal emotions, it is often at odds with the views of the general public. Ask the man or woman in the street if animals have emotions, and they will say “of course.” They know their pet dogs and cats have all sorts of emotions, and by extension they grant them to other animals as well. But ask professors at a university the same question, and many will scratch their heads, look bewildered, and ask what exactly you mean. How do you even define emotions? They may follow B. F. Skinner, the American behaviorist who promoted a mechanistic view of animals, by dismissing emotions as “excellent examples of the fictional causes to which we commonly attribute behavior.” True, it is nowadays hard to find a scientist who outright denies animal emotions, but many are uncomfortable talking about them.

Readers who feel insulted on behalf of animals by those who doubt their emotional lives should keep in mind that without the scrutiny typical of science, we’d still believe the earth is flat or that maggots spontaneously crawl out of rotting meat. Science is at its best when it questions common preconceptions. And even though I disagree with the skeptical view of animal emotions, I also feel that just affirming their existence is like saying that the sky is blue. It doesn’t get us very far. We need to know more. What kind of emotions? How are they felt? What purpose do they serve? Is the fear presumably felt by a fish the same as that felt by a horse? Impressions are not enough to answer such questions. Look how we study the inner life of our own species. We bring human subjects into a room where they watch videos or play games while strapped to equipment that measures their heart rate, galvanic skin response, facial muscle contractions, and so on. We also scan their brains. For other species, we need to take the same close-up look.

I love to follow wild primates around, and over the years I’ve visited a great many field sites in far corners of the earth, but there’s a limit to what I or anyone else can learn from this. One of the most emotional moments I ever witnessed was when wild chimpanzees high above me suddenly burst out in bloodcurdling screams and hoots. Chimps are among the noisiest animals in the world, and my heart stood still not knowing the cause of the commotion. As it turns out, they had captured a hapless monkey and were leaving little doubt about how much they prized its meat. While I watched the apes cluster around the possessor of the carcass and feast, I wondered if he shared it with them because he had more than enough to eat and didn’t care or because he wanted to get rid of all those beggars, who couldn’t stop whining while gingerly touching every morsel he brought to his mouth. Or perhaps, as a third possibility, his sharing was altruistic, based on how much he knew the others wanted a piece. There is no way to know for sure from watching alone. We’d need to change the hunger state of the meat owner or make it harder for the others to beg. Would he still be as generous? Only a controlled experiment would allow us to get at the motives behind his behavior.

This has worked extremely well in studies on intelligence. Today we dare speak of animal mental life only after a century of experiments on symbolic communication, mirror self-recognition, tool use, planning for the future, and adoption of another’s viewpoint. These studies have blown big drafty holes in the wall that supposedly separates humans from the rest of the animal kingdom. We can expect the same to happen with respect to the emotions, but only if we adopt a systematic approach. Ideally, we’d use findings from both the lab and the field, putting them together as different pieces of the same puzzle.

Not only are we keenly interested in emotions; they structure our societies to a degree that we rarely acknowledge.

Emotions may be slippery, but they are also by far the most salient aspect of our lives. They give meaning to everything. In experiments, people remember emotionally charged pictures and stories far better than neutral ones. We like to describe almost everything we have done or are about to do in emotional terms. A wedding is romantic or festive, a funeral is full of tears, and a sports match may be great fun or a disappointment depending on its outcome.

We have the same bias when it comes to animals. An Internet video of a wild capuchin monkey cracking nuts with stones will get far fewer hits than one of a buffalo herd driving lions away from a calf: the ungulates take the predators on their horns, while the calf frees itself from their claws. Both videos are impressive and interesting, but only the second one pulls at our heartstrings. We identify with the calf, hear its bleating, and are delighted by the reunion with its mother. We conveniently forget that for the lions there is nothing happy about this outcome.

That’s another thing about the emotions: they make us take sides.

Not only are we keenly interested in emotions; they structure our societies to a degree that we rarely acknowledge. Why would politicians seek higher office if not for the hunger for power that marks all primates? Why would you worry about your family if not for the emotional ties that bind parents and offspring? Why did we abolish slavery and child labor if not for human decency grounded in social connectedness and empathy? To explain his opposition to slavery, Abraham Lincoln specifically mentioned the pitiful sight of chained slaves he had encountered on trips through the South. Our judicial systems channel feelings of bitterness and revenge into just punishment, and our health care systems have their roots in compassion. Hospitals (from the Latin hospitalis, or “hospitable”) started out as religious charities run by nuns and only much later became secular institutions operated by professionals. In fact, all our most cherished institutions and accomplishments are tightly interwoven with human emotions and would not exist without them.

This realization makes me look at animal emotions in a different light, not as a topic to contemplate by itself but as capable of shedding light on our very existence, our goals and dreams, and our highly structured societies. Given my specialization, I naturally pay most attention to our fellow primates, but not because I believe their emotions are inherently more worthy of attention. Primates do express them more similarly to us, but emotions are everywhere in the animal kingdom, from fish to birds to insects and even in brainy mollusks such as the octopus.

I will only rarely refer to other species as “other animals” or “nonhuman animals.” For simplicity’s sake, I will mostly call them just “animals,” even though for me, as a biologist, nothing is more self-evident than that we are part of the same kingdom. We are animals. Since I don’t look at our own species as emotionally much different from other mammals, and in fact would be hard-pressed to pinpoint uniquely human emotions, we had better pay careful attention to the emotional background we share with our fellow travelers on this planet.


Reprinted from Mama’s Last Hug: Animal Emotions and What They Tell Us about Ourselves by Frans de Waal. Copyright © 2019 by Frans de Waal. Used with permission of the publisher, W.W. Norton & Company, Inc.

Frans de Waal
Frans de Waal
Frans de Waal has been named one of Time magazine’s 100 Most Influential People. The author of Are We Smart Enough to Know How Smart Animals Are?, among many other works, he is the C. H. Candler Professor in Emory University’s Psychology Department and director of the Living Links Center at the Yerkes National Primate Research Center. He lives in Atlanta, Georgia.

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