There are even examples of social learning in which the benefits, instead of going to the performer, go to someone else. At the Mahale Mountains in Tanzania, I regularly saw a chimpanzee walk up to another, vigorously scratch the other’s back with his or her fingernails, then settle down to groom the other. In between the grooming, more scratching might follow. This behavior has been known for a long time and has thus far been reported for only one other field site. It is a locally learned tradition, but here’s the rub: when one scratches oneself, it is usually due to itching, and the act brings instant relief. In the case of the social scratch, however, the performer does not feel relief—the recipient does.41
Primates occasionally learn habits from others that do pay off, such as when chimpanzee youngsters learn to crack nuts with stones. But even then things are not as simple as they appear. Sitting next to their nut-cracking moms, infant chimps are total klutzes. They put nuts on top of stones, stones on top of nuts, and push them all together in a heap only to rearrange them over and over. They gain nothing from this playful activity. They also hit nuts with a hand, or stamp them hard with a foot, which fails to crack anything. Palm and panda nuts are far too tough for them. Only after three years of futile efforts do young chimps have enough coordination and strength to break open their first nut with a pair of stones, but they still have to wait until they are six or seven to reach adult skill levels.42 Since they utterly fail at this task for so many years in a row, it is unlikely that food is the incentive. They may even experience negative consequences, such as smashed fingers. Yet young chimps happily persist, inspired by the example of their elders.
How little rewards matter is also evident from habits that lack benefits. In our own species, we have fads such as wearing a baseball cap backward or pants that hang low enough to impede locomotion. But in other primates, too, we find seemingly useless fashions and habits. A nice example is the N-family in a group of rhesus monkeys that I observed long ago at the Wisconsin Primate Center. This matriline was headed by an aging matriarch, Nose, all of whose offspring had names starting with the same letter, such as Nuts, Noodle, Napkin, Nina, and so on. Nose had developed the odd routine of drinking from a water basin by dipping her entire underarm into it, then licking her hand and the hair on her arm. Amusingly, all her offspring, and later her grandchildren adopted the exact same technique. No other monkeys in the troop, or any other that I knew, drank like this, yet there was absolutely no advantage to it. It did not allow the N-family to access anything that other monkeys had no access to.
Or take the way chimpanzees sometimes develop local dialects, such as the excited grunts uttered while snacking on tasty food. These grunts differ not only from group to group but also per food type, such as a particular grunt heard only while they eat apples. When the Edinburgh Zoo introduced chimpanzees from a Dutch zoo to its residents, it took those others three years to get socially integrated. Initially, the newcomers uttered different grunts while eating apples, but by the end they converged on the same grunts as the locals. They had adjusted their calls so that they sounded more like those of the residents. While the media hyped this finding by saying that Dutch chimps had learned to speak Scottish, it was more like picking up an accent. The bonding between individuals of different backgrounds had resulted in conformism, even though chimps are not particularly known for vocal flexibility.43
Clearly, social learning is more about fitting in and acting like others than about rewards. This is why my book on animal culture was entitled The Ape and the Sushi Master. I chose this title partly to honor Imanishi and the Japanese scientists who gave us the animal culture concept, but also because of a story I had heard about how apprentice sushi masters learn their trade. The apprentice slaves in the shadow of the master of an art requiring rice of the right stickiness, precisely cut ingredients, and the eye-catching arrangements for which Japanese cuisine is famous. Anyone who has ever tried to cook rice, mix it with vinegar, and cool it off with a handheld fan so as to mold fresh rice balls in one’s hands knows how complex a skill it is, and it is only a small part of the job. The apprentice learns mostly through passive observation. He washes the dishes, mops the floor, bows to the clients, fetches ingredients, and in the meantime follows from the corners of his eyes, without ever asking a question, everything the sushi master does. For three years he watches without being allowed to make actual sushi for the patrons of the restaurant: an extreme case of exposure without practice. He is waiting for the day when he will be invited to make his first sushi, which he will do with remarkable dexterity.
Whatever the truth about the sushi master’s education, the point is that repeated observation of a skilled model firmly plants action sequences in one’s head that come in handy, sometimes much later, when one needs to carry out the same task. Tetsuro Matsuzawa, who studied nut-cracking in West African chimpanzees, views social learning as based on a devoted master-apprentice relationship, in the same way that I developed my Bonding-and Identification-based Observational Learning model (BIOL).44 Both views reject the traditional focus on incentives and replace it with one on social connections. Animals strive to act like others, especially others whom they trust and feel close to. Conformist biases shape society by promoting the absorption of habits and knowledge accumulated by previous generations. This by itself is obviously advantageous—and not just in the primates—so even though conformism is not driven by immediate benefits, it likely assists survival.
What’s in a Name?
Konrad Lorenz was a big corvid fan. He always kept jackdaws, crows, and ravens around his house in Altenberg, near Vienna, and considered them the birds with the highest mental development. In the same way that I, as a student, took walks with my tame jackdaws flying above me, he traveled with Roah, his old raven and “close friend.” And like my jackdaws, the raven would come down from the sky and try to make Lorenz follow by moving his tail sideways before him. It is a quick gesture that is not easily noticed from a distance yet hard to miss if done right in front of your face. Curiously, Roah used his own name to call Lorenz, whereas ravens normally call one another with a sonorous, deep-throated call-note described by Lorenz as a metallic “krackkrackkrack.” Here is what he said about Roah’s invitations:
Roah bore down on me from behind, and, flying close over my head, he wobbled with his tail and then swept upwards again, at the same time looking backwards over his shoulder to see if I was following. In accompaniment of this sequence of movements Roah, instead of uttering the above described call-note, said his own name, with human intonation. The most peculiar thing about this was that Roah used the human word for me only. When addressing one of his own species, he employed the normal innate call-note.45