By Björn Ólafsson, Sentient Science, May 1, 2024
I have two lovebirds. Literal lovebirds, mind you, the bright orange-green parrots whose genus name is Agapornis. When we adopted them, the feathered pair quickly started using human forms of communication — mimicking the sound of a kiss to express affection and giving a heads’ up to greet us. In the wild, lovebirds communicate all the time in various ways — chirping, whistling, preening — but they don’t blow kisses.
Because my two birds behaved differently than a wild pair, their expression could be considered a form of culture. Psychologists define culture as behaviors passed down through generations, but it’s more than just holidays, music and recipes. One subset of culture — called cumulative culture by researchers — describes the phenomenon of a group learning a skill too complicated to master alone, often over multiple generations. Until recently, many scientists believed only humans were capable of cumulative culture, but two new studies are upending this belief.
In March, scientists at Queen Mary University published a study of their experiment with bumblebees, demonstrating these winged insects were capable of training each other to solve a puzzle too complicated for one bee to solve alone. That same month, another group of researchers published the results of a different puzzle experiment, this time with chimpanzees. These two studies challenge the idea that cumulative culture is inherently human.
“People used to think [bees] were automatons,” says Dr. Alice Bridges, lead researcher on the bee culture study in a conversation with Sentient, “But these are clearly animals that can learn new things.” Scientists like Bridges have come to believe that many animals can learn from each other, even to master quite complicated tasks.
Culture: Not Just for Homo Sapiens
For centuries, most Western philosophers — from Aristotle to Descartes — believed animals weren’t capable of conscious thought at all, never mind capable of creating culture. But then in 1952, a Japanese anthropologist named Kinji Imanishi wrote an essay — a dialogue between a monkey, a human and a bee — defending the possibility of animal culture.
One year later, new evidence emerged: a young macaque monkey in Japan named Imo started taking sweet potatoes to a nearby stream and washing them before eating. Imo’s idea spread like wildfire, and soon the entire group was scrubbing their tasty taters before taking a bite.
Today we know that examples of animal culture abound, and all across the animal kingdom. Orcas wear dead salmon as hats. Songbirds teach each other melodies. Groups of female fruit flies prefer mates with specific colors. Female bottlenose dolphins use sponges to hunt. In a particularly cute example, one group of chimps in Uganda were known to rub their backs against vines, which they learned from their disabled chimp friend Tinka, who used this technique to scratch his back after an injury sustained from local hunting traps.
Yet scientists still believed cumulative culture, an advanced, often multi-generational form of social learning, to be unique to humans. Social learning in humans looks like what happens when we learn differential math equations in school — the task might be too difficult to solve alone, but possible with teachers or with support from peers. Even though scientists observed learning in animals — apes creating tools to use for instance — the tools were relatively simple, not enough evidence of true social learning, scientists seemed to agree.
As recently as a decade ago, scientists hadn’t yet seen any evidence of cumulative culture in non-humans, with some even saying it was categorically impossible. But in the 2010s, researchers began noticing that the food-washing behaviors of Japanese monkeys were growing incredibly complicated over time. First, the sweet potatoes were simply washed in a stream, then the monkeys began using salt water for added flavor, and digging their own pools for solitary enjoyment of their treat. This added complexity was thought to show evidence for cumulative culture. And now, we have even more evidence of this type of social learning, in bees and chimpanzees.
Training the Bees to Be Puzzle Trainers
In the Queen Mary experiment, bees who were placed in a box needed to solve a puzzle to receive a reward — in this case, sugar. The puzzle is a bit tricky, and none of the bees were able to learn the two-step solution on their own, even when left in the box for nearly a month. In fact, they seemingly became frustrated by the puzzle, “like a toddler throwing a tantrum,” says Bridges.
Next, the researchers trained a new set of bees, which they dubbed the “demonstrators.” These fuzzy influencers were taught by humans to solve the puzzle step-by-step, with syrup given as a reward each time they learned a new part of the answer. After two days of puzzle bootcamp, the demonstrator bees were paired with the untrained bees. A few minutes later, a third of the untrained bees were able to learn the complicated task and earn the sugar. And after the demonstrator bees were removed, the “untrained” bees were still able to solve the puzzle.
In an independently organized study in chimpanzees, the researchers offered peanuts instead of sugar as a reward for completing a slightly more complicated task: pulling a two-step lever with a more complex three-step mechanism.
In both experiments, the finding was the same. On their own, the animals couldn’t solve it, but a trained animal could successfully teach it to others.
In other words, these experiments showed that chimps, like bees and like humans, have the capacity for cumulative culture.
Animal Culture Should Change How We Interact With Them
Animal culture, much like the animal personality, is rarely discussed in conversations about animal welfare, that is, how we treat animals — whether it’s wild animals affected by human conservation efforts or farm animals raised for food, to say nothing of animals in laboratories, zoos, or those used to entertain humans. But ignoring these sociological factors might end up causing more harm to animals than good.
Understanding animal culture could help humans improve our human-animal interactions. After all, knowledge is shared within herds and flocks — that is, it’s shared culturally. Bighorn sheep and other large mammals don’t travel migration routes instinctively, but learn them from each other. Historically, when animals have been relocated by humans, it has taken several decades and in some cases a century to adapt to the new winter migration route.
The Queen Mary researcher, Bridges, raises a hypothetical: what if conservationists find two groups of chimpanzees in a habitat at risk of destruction, each group with its own unique culture. Do the conservationists need to preserve both groups, not just to save more animals, but to conserve both unique cultures? Most people see the value in preserving human cultures at risk of disappearing. Why should animal culture be any different?
Conservationists are already confronting these questions. The regent honeyeater, a beautiful glossy black songbird with speckles of yellow from southern Australia, has become critically endangered. As the population has declined, so too has their culture — males’ songs no longer have the complexity of their ancestors, to the point that many of the regent honeyeaters can no longer even learn their own culture, forced to mimic the sounds of other species. Should we endeavor to save the honeyeaters’ cultural heritage, in addition to just paying attention to raw population numbers?
It’s not just wild animals. Most mammals and birds on the planet are found on industrial-scale factory farms, where it may be more difficult to create unique culture given the unnatural conditions — small and packed living quarters. Yet according to researchers, most farm animals like cows, pigs, and chickens have demonstrated awareness and an ability to learn.
Bridges hopes findings like these may help people think more open-mindedly about animals, both the human and non-human kind. “We’re not a pinnacle of evolution above them,” she says, “Not everything we do is complex, not everything they do is simple.”
Whether bees pulling levers, chimps solving puzzles or lovebirds blowing kisses, scientists are still scratching the surface of the culture and learning of which animals are capable.
