Animals Say Hello, but Do They Say Goodbye? - The New Yorker

In February, a pop-up science column, Annals of Inquiry, is appearing in place of Kyle Chayka’s column, Infinite Scroll. Chayka will return in March.

Jane Goodall, the late primatologist, was known for her imitations of chimpanzee greetings. When she met with Prince Harry, in 2019, she approached him slowly, making panting noises through circular lips. She prompted him to pat her lightly on the head, then reached up for an embrace, making soft hooting sounds. During her career, Goodall observed chimps engaging in more than a thousand such greetings. They sometimes touched their lips together, breathed into one another’s open mouths, or stood on two legs and hugged.

Greetings are found across the animal kingdom. Dogs sniff each other’s rears, African elephants swing their trunks, and songbirds peck at one another’s feathers. Orcas face off in rows before rushing into a sort of whale mosh pit, in which they slap tails, squeak, and whistle. Greeting behaviors are universal enough that they are thought to be ancient, emerging before primate groups evolved. When a spectral bat wraps its wings around another bat in what looks like a hug, it seems to be communicating something that we’re familiar with.

Goodbyes, on the other hand, were long understood as a behavior that only humans perform. In 2013, Goodall watched as a chimpanzee named Wounda, who had almost died at the hands of poachers, was released to a Congolese animal sanctuary. Before Wounda walked into the trees, she hugged Goodall for several seconds. After Goodall died, this past October, some claimed that the video showed Wounda saying goodbye—but the Jane Goodall Institute had only described the embrace as a way of “giving thanks.” Indeed, a survey of researchers at ten wild-chimpanzee sites, co-conducted in 2016 by Lucy Baehren, a Cambridge student, documented numerous chimp greetings but nothing that could be construed as a “leave-taking” behavior. “The idea that nonhuman animals say goodbye did not exist,” Susana Carvalho, a primatologist and a paleoanthropologist at Oxford who became Baehren’s supervisor, told me.

The mystery of the missing farewells inspired many theories. It led scholars to think that goodbyes must have evolved separately from greetings, and more recently. The study of leave-taking was assumed to be more complicated than the study of greetings. Some researchers suggested that goodbyes required cognitive abilities that many nonhuman animals might lack, such as the capacity to imagine and plan for the future. “Why are you going to say goodbye if, upon return, no one remembers?” Carvalho said.

But a few years ago, after analyzing dozens of hours of footage of Chacma baboons, Carvalho and Baehren noticed a subtle body movement that happened only right before baboons ended a social interaction. They went on to publish what they called the first empirical evidence of a nonhuman animal’s goodbye. “The presence of leave taking in baboons could suggest a deep evolutionary history of the behaviour, present since the last common ancestors of humans and baboons,” they wrote. (Humans and baboons diverged more than twenty million years ago.) Goodall argued that greetings were proof of how similar humans were to other animals. Goodbyes gained the opposite meaning: they symbolized our differences from other creatures. Where would a new theory of leave-taking leave us?

The sociologist Erving Goffman thought that when two people encounter each another, they both try to manage the impression that they’re making, following a kind of script that ends with a goodbye. “The goodbye brings the encounter to an unambiguous close, sums up the consequence of the encounter for the relationship, and bolsters the relationship for the anticipated period of no contact,” he wrote in his 1971 book, “Relations in Public.” Goffman also described the special awkwardness of “failed departures”—for example, when two people say goodbye, only to start walking in the same direction.

In the seventies, a communication researcher at Purdue University, Mark Knapp, argued that behavioral research—Goffman’s work notwithstanding—had neglected goodbyes, even though they were a ritual that everyone participated in. “Unique and terribly human interpersonal forces are unleashed when people say goodbye to one another,” Knapp and his colleagues wrote. They tried to break down leave-taking beat by beat, noting, for example, that goodbyes could be preceded by “explosive hand contact”—slapping one’s hands on the surface of a table or on one’s thighs. The linguists Emanuel Schegloff and Harvey Sacks described verbal markers that indicated an interaction was wrapping up, for example, “well...” or “O.K....” Others found that, for children, greetings may come more naturally than goodbyes. (Think of the kid who says goodbye to every stranger on a bus, or to every diner in a restaurant.) One hint that the goodbye requires effort, and carries real social weight, is that we even have a name for its absence: to leave a party or a bar without saying farewell is to make an “Irish exit.” Apparently, the same phenomenon is sometimes known in Germany as “the Polish goodbye” and in France as leaving “in the English way.”

After I started writing this piece, I became hyperaware of the goodbyes in my life. Visiting a restaurant in Brooklyn where I used to work, I remembered that it was customary to kiss regulars on both cheeks, as some Europeans do. I’m not sure who started the ritual, but it became rude to skip it, even when I was saying farewell to someone with a cold or trying to leave at the end of a tiring shift. My husband’s father, when talking on the phone, will interrupt you mid-sentence to say, “Well, I should probably let you go now,” and then hang up. It’s jarring, but charming, and no one holds a grudge. I’m told that acquaintances hint at an impending farewell by gesturing toward the future, saying something like “So what are you up to this weekend?”

Goodbyes can be staggering in their variety, and they can’t be predicted based on how a person says hello. In the early twentieth century, on the Andaman Islands, social anthropologists observed ritualistic greetings that involved wailing and weeping. Locals took their leave from friends and family in a much more demure way: a person would lift their hand toward their mouth and blow air on it gently. Many familiar ways of saying goodbye are actually quite recent. The “hello” handshake has been around for a long time, but there are few recorded instances of a “goodbye” handshake until the fifteenth century, according to Torbjörn Lundmark, the author of “Tales of Hi and Bye: Greeting and Parting Rituals Around the World.” He notes that, as recently as the nineteen-seventies, handshakes weren’t a commonly recognizable way of saying farewell in China.

Lundmark also wrote that a farewell meal in China often includes long thin noodles, to symbolize the winding road ahead, but not cut-up pears, whose Chinese word sounds the same as the word for “separation.” A host may prolong the encounter, he added, by insisting that guests stay as long as possible—a ritual that “can reach a highly emotional pitch, ending up almost in an outright argument between host and visitor.” In England, leave-taking is similarly drawn out, the anthropologist Kate Fox writes in “Watching the English: The Hidden Rules of English Behavior.” Just when you think that the farewell has been accomplished, one of the hosts or guests might start the process all over again.

Primates were rumored to say goodbye at least a few times before Baehren and Carvalho’s study of Chacma baboons. In the 1982 book “Chimpanzee Politics: Power and Sex Among Apes,” the primate behaviorist Frans de Waal wrote that chimps in a sign-language experiment learned to signal “bye-bye.” A gorilla in a zoo in Arnhem, in the Netherlands, is said to have kissed zookeepers before going inside her enclosure. But Baehren and Carvalho pointed out that these behaviors, which took place rarely and in captivity, might only be imitations of human communication.

Captive chimpanzees and bonobos do make gestures and share eye contact at the beginning and end of activities that they do together. A skeptic could consider these “exit behaviors” rather than leave-taking ones, Evelina Daniela Rodrigues, a researcher at Universidade Católica Portuguesa, told me. (A human exit behavior might include checking around your table at a café, to make sure you haven’t left anything behind.) It’s also difficult to distinguish between “goodbye” and “do you want to come with me?” Rodrigues said. Baboons will show their buttocks to others before walking away; the entire troop then departs. This could be a signal to the group, instead of a leave-taking behavior. In 2022, while reviewing videos of twenty-two wild chimpanzees in Guinea, Rodrigues found very few instances when chimps ended a social interaction with a behavior that could be considered leave-taking. In addition, those behaviors were repeated in other contexts, so they might not have been goodbyes. It’s been difficult to study leave-taking, Rodrigues said, because researchers haven’t agreed on a precise definition or a way of searching for it.

Baehren and Carvalho’s process was to record all of the times a baboon ended a social interaction, wait to make sure they really parted, and then rewind to analyze the encounters. They accumulated more than sixty-five hours of footage from Gorongosa National Park, in Mozambique, where baboons live in large groups that feature strong female relationships; males tend to come and go. Baehren was the first to notice that baboons appeared to shift their bodies and gaze in the direction of an impending departure. (They didn’t shift their bodies when they were alone and preparing to head in a new direction, or when they were close to another baboon with whom they weren’t interacting.) Carvalho declared the finding a breakthrough. “We could say out loud: primates do say goodbye, and we have found how baboons do it,” she said.

I have to admit that, when I saw photos of the baboon goodbye, my first thought was that a human would be considered pretty rude for doing the same. Imagine you’re at dinner with a friend; at some point, she turns her torso slightly, gets up, and walks off. But I had to check myself. If goodbyes change from one country to the next, then we surely can’t expect them to translate between species. Human goodbyes depend heavily on context; something as subtle as a nod of the head is sometimes an acceptable way to part. Perhaps, in context, the baboons’ gesture is as friendly as a handshake. I wondered how often we misunderstood animals in an effort to interpret them with our terribly human assumptions.

Lydia Hopper, a primatologist and comparative psychologist at Johns Hopkins University who was not involved in the research, thought it was plausible that a nonhuman animal’s goodbye would be subtle and gestural. “Even if we had been looking, we might have missed it,” she said. She considered Carvalho and Baehren’s finding “tantalizing,” but not definitive. “Maybe animals do perform some leave-taking behaviors,” she told me. “Maybe it’s not to the same frequency or degree as humans, and not the same strength or style as humans.”

Human goodbyes have a lot to do with how strong our bonds are. I am likely to say one goodbye to my sister and another to a colleague or a barista. Ironically, I’d probably be nicer to a stranger than I sometimes am to my relatives—but not too much nicer, which would be creepy. “If you’re buying something at a store, you are not going to hug them when you check out,” Hopper said. But intimacy can’t explain everything. In November, Hopper wrote in a scientific paper that our goodbyes depend in part on an understanding of what’s going to happen in the future. Last summer, after my sister moved to my neighborhood and we began going to the grocery store and the gym together, I noticed that our farewells became truncated—we’d exchange a brusque goodbye and then leave the other on the sidewalk. But when I parted with my best friend late last year, in Berlin, I knew I’d be away from her for many months. We hugged each other close and said, “I love you.”

Our relationship to time may be one of the most important differences between us and other animals. Cats and dogs certainly greet us, and they act troubled when their people prepare to leave them, whether by whining or curling up in an open suitcase. But they presumably can’t understand “I’ll see you in two weeks.” To a dog, our fervent and prolonged goodbyes at the front door might seem as peculiar and impenetrable as the greetings of an orca do to us. Perhaps it would be better to give our pets an Irish goodbye (or one in the English way).

Humans have a complicated history of assessing nonhuman animals. In some cases, we have overinterpreted their behaviors. At the beginning of the twentieth century, a horse named Clever Hans was credited with talking and doing math—until a psychologist determined that he was responding to involuntary cues. But in other instances we can be prone to what De Waal has called “anthropodenial,” an overcorrection from anthropomorphism. Researchers are so careful to differentiate humans from other species that they say primates have a “close social associate,” not a friend, and that they engage in “vocalized panting,” not laughing. Animals could have ways of saying goodbye that we haven’t acknowledged yet.

We shouldn’t assume that primates are missing the cognitive capacities that I employ with, say, my sister or my barista, according to Cat Hobaiter, a primatologist at the University of St. Andrews. Wild chimpanzees can plan where they are going to sleep based on what fruit they want for breakfast in the morning. A male chimpanzee at the Furuvik Zoo, in Sweden, hid rocks from zookeepers and threw them at visitors the following day. Chimpanzees recognize individuals that they haven’t seen for years. “They have a sense of absence, and I certainly think that they have a sense of death,” Hobaiter told me.

If primates may be capable of saying farewell, why wouldn’t they? There are many explanations, Hobaiter said. Long after two chimpanzees part, for example, they can trade vocalizations from one treetop to another. “The species at which we’re currently looking might not need to take leave,” Hobaiter said. It’s a striking thought—that other primates simply don’t need goodbyes as much as we do.

Goffman wrote that our farewells help us transition into “a state of decreased access” to one another. “One of the biggest stresses to social bonds is when somebody leaves you,” Hopper said. A goodbye manages the uncertainty of separation; it’s a signal that you won’t be gone forever, that you’re parting on good terms, and that eventually you’ll pick things up where you left off. Studying the rest of the animal kingdom reminds us just how much we’ve complicated that message. For a baboon, maybe it’s enough to turn away.♦

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