We’ve done a list on mental illness in other animals, but that’s just the tip of the iceberg. As it turns out, we’re nowhere near as unique as greedy religious nutjobs had your ancestors believe; we’re not even the only ones with religion.
Knowledge-sharing, especially from one generation to the next, put humans at the top of the food chain. It’s basically the definition of culture. It’s also found in other species. For example, baboons teach each other the best foraging routes; fledgling birds learn how to fly by watching their parents; and rats learn safe foods by smelling each other’s breath. There are countless other examples. Even fish have their “schools,” which, as it turns out, do better with experienced teachers. But it’s not just sociable species; solitary animals also show a basis for culture. Young tortoises, for instance, learn to navigate around new obstacles by watching others do it first.
Needless to say, as species go extinct, so do their cultures. The last surviving North Atlantic right whales—all but wiped out by human whalers—now lack the knowledge of their old ancestral feeding grounds, further endangering the species. That’s not to say culture is always a good thing, though. Sometimes, established ways of life fall out of kilter with the environment and a non-adaptive culture can lead a species to oblivion. Humans are finding this out the hard way.
9. Weird trends
In the age of TikTok, human trends are getting weirder all the time. But so are other animals’. White-faced capuchin monkeys in Costa Rica exhibit a number of unusual traditions, such as smelling each other’s fingers and, as a kind of game, biting off a clump of another monkey’s fur and holding it in the mouth while the other tries to get it back. Importantly, these traditions tend to be fleeting—usually lasting roughly a decade (similar to our own decade-long fads and fashions). They’re also pretty localized, so trends seen in one group may not be in the next.
Typically, these trends have no clear survival advantage. In fact, a new trend seen in one group of the Costa Rican capuchins actually posed a threat to their survival: inserting a long, dirty finger, right up to the first knuckle, into another monkey’s eye socket just above the eyeball. Those on the receiving end are clearly uncomfortable, wincing and batting their eyelids—but they don’t try to stop it. Actually, they encourage it and the behavior can last up to an hour. You might compare it to getting a tattoo or a piercing, but with nothing to show for the pain—except, perhaps, as one theorist thinks, a strengthening of social bonds.
In addition to weird behavioral trends, we also find fashion in animals. Bearded vultures, whose feathers are white, apply make-up in the form of iron-rich soil. Like human fashions, this signifies status—with the older, more dominant birds wearing the most color.
There’s even evidence for fashion in fruit flies. One study found that virgin female fruit flies preferred green-dusted males after seeing other females mate with them.
Then there are the chimps who wear a single blade of grass in their ears. It started in 2010, when a chimpanzee in Zambia spontaneously stuck one in her ear and left it there. Despite it serving no obvious purpose—certainly no direct survival purpose—other chimps followed, then others, until four different groups were doing it.
7. Drug use
Drug use is everywhere in the animal kingdom. Jaguars in the Amazon independently seek out the DMT-containing yage vine used by humans to make ayahuasca; lemurs chew on narcotic millipedes; and dolphins get high on pufferfish before floating upside down in a daze staring at their own reflections.
In fact, non-human animals like drugs so much they’re willing to put up with the downsides. Bighorn sheep addicted to lichen, for instance, grind their teeth right down to the gums scraping their drug of choice from the rocks. Spider monkeys, drunk on fermented fruit, throw up and fall out of trees. And one intoxicated moose in Sweden had the opposite problem, getting stuck in a tree instead.
Animals also use drugs to cope with bad moods. In one famous study, rats kept in small cages with nothing to engage their curious minds were more likely to choose a sweetened morphine solution over water—and they drank themselves to death on the stuff. Even fruit flies turn to booze if they don’t find a mate.
6. Facial expressions
What could be more uniquely human than a smile or a frown, or any of the emotions we display? As it turns out, facial expressions are found in many other animals. Sheep, for example, not only show facial expressions, they recognize them too. Studies have shown their ability to distinguish between calm, startled, and fearful expressions in photos of other sheep. They can even tell humans apart by looking at their faces.
Domesticated dogs are also able to produce facial expressions. Wolves in the wild don’t have the same range of movement in their eyebrows, eyes, lips, and ears, which suggests an evolutionary (or selective breeding) pressure for interspecies (human-dog) communication.
5. Sense of humor
Did humans come up with laughter? It seems unlikely. According to some researchers, it evolved from the panting of play-fighting apes. The panting/laughing sound, as in humans, reassured others that the fight wasn’t serious. Tickle any great ape today and you’ll hear the same noise (assuming they’re in a good mood).
Some apes even show signs of a more complex sense of humor. The late Koko the Gorilla, who could use American Sign Language, once tied her trainer’s shoelaces together and made the sign for “chase.” Some researchers think a sense of humor is something all mammals have, while others think it’s inherent to all animals—even insects. After all, they say, we’re continually finding out they’re more intelligent than we thought and, as Darwin observed, animal intelligence varies mainly in degree, not in kind. So far most research into non-human humor has focused on the great apes, but it’ll be interesting to see where it leads.
4. Complex language
Koko the Gorilla’s humorous use of language also shows a grasp of complexity. For example, when asked to list things that are hard, she said both “rock” and “work.” In other words, she understood the word had two meanings.
Surprisingly, though, the most complex language besides our own isn’t to be found in great apes—or even the mammals of the sea—but in prairie dogs. These highly social animals have different noises, or “words,” for different predators. Their warning call for coyotes, for example, is different to their warning call for hawks, humans, and so on. But that’s not all. They also have “describing words” for a predator’s characteristics, allowing them to say how big they are and what color and so on. This means they can form sentences. And in captivity, under laboratory conditions, they can also describe things they’ve never seen before.
So far we’ve only scratched the surface of prairie dog language. It’s one thing to match the sounds and behavior with predators, but prairie dogs are continually chatting. When their behavior doesn’t change significantly (e.g. running and hiding) in response to these noises (like ours generally doesn’t when we’re talking), it’s practically impossible to know what they’re saying.
Surely storytelling sets us apart from the rest of the animal kingdom? Stories are to humans as honey is to bees, right? From history books to video games, science to religion, telling stories is our sole occupation. As it turns out, though, many other animals do the same—including bees. The bees’ famous waggle dance, in which they use physical movements to communicate the location of food, includes information about distance, direction, difficulty of route, and the value of the prize. However you look at it, they’re sharing a narrative. And if insects can do it, why not mammals?
It has been argued that dogs are constructing a narrative when they paw at their food bowl or scratch at the door to go out. They’re referring to problems and solutions and, in the case of wanting to go for a walk, to other locations as well.
There’s no reason to think of non-human storytelling as inferior to our own. It’s doubtful the average joe could do the waggle dance, for instance. In fact, some animals may be much better at storytelling than we could ever dream of: According to some, dolphins may use their sonar capabilities to tell stories in 3D by projecting sono-pictorial holograms for each other.
According to Jane Goodall, chimps appear to feel awe. In the course of her research she saw them swaying rhythmically to a waterfall then sitting down to watch it. This of course has features of human spirituality, but it’s impossible to say it’s the same. Other chimpanzee behaviors, for example, such as throwing gathered stones to leave markings on trees almost suggest a religion… or they might just enjoy it.
What we do know, however, is that other animals ceremonialize death. Elephants perform parades when an elephant dies, with the corpse drawing not only its own herd but members of other herds too. Interestingly, they stay close to their fallen even when a corpse attracts predators. It calls to mind the kind of courage that humans often draw from their faith, or convictions.
Dolphins do it too. In the year 2000, the corpse of a female found on a seabed near Japan was accompanied at all times by two males. Her guardians surfaced only for air. And when divers tried to remove the corpse, the males fought them off on two separate days. By the third day, the corpse had disappeared. In another case, dolphins were observed guarding the corpse of an infant and chasing off seabirds even as it rotted.
Chimps show the same kind of reverence. When a baby dies, its mother will continue to care for it, carrying and grooming it for days, weeks, or even months afterward. She’ll only stop once the corpse has decayed beyond all recognition. Other apes, including gorillas, baboons, macaques, and lemurs, also have death rituals. So do birds; crows, jays, and others often gather in trees around their fallen, apparently to mourn.
Fire helped humans to dominate the Earth. As well as allowing us to live in freezing environments, it opened up our food options and sped up digestion. No other animal cooks food with fire—at least as far as we know. But some are definitely capable of it. One bonobo learned how to start a fire using fuel and matches provided by humans, which it then used to cook burgers and marshmallows—before teaching this skill to his son. Admittedly, the bonobo was repeatedly shown the film Quest for Fire to put the idea in his mind, but he still picked up the skill for himself. And, in any case, many humans today can’t start a fire even in the most favorable conditions.
Of course, there’s a lot more to cooking than fire. But humans aren’t alone in food preparation—whether for taste or digestion. Some Japanese macaques wash sweet potatoes before they eat them, and prefer to use salt water for flavor. Pigs wash their food too; they’ve been seen washing dirty apple chunks in a stream. Shrikes, meanwhile, impale their prey on thorns or barbed wire and allow them to degrade before eating. Capuchin monkeys leave palm nuts in the sun to make them easier to crack. Interestingly, bigheaded ants have a more advanced form of cooking: putting food on their larvae’s bellies, for them to spit enzymes onto it and thereby make it easier to digest.