Anne Russon has studied imitation among orangutans at Birute Galdikas’s Camp Leakey. These apes are being returned to the Indonesian rain forest after captivity. Some imitated orangutans who know the ways of the wild, not only trying the same plants for food but copying the methods used to peel and otherwise get at the edible parts. But other orangutans showed little inclination to return to the wild and hung around camp instead. They imitated such cool activities as sawing wood, washing clothes, and writing in notebooks (their notes were never legible). They borrowed canoes (but did not return them). Siswoyo, an orangutan in her twenties who was permanently hunched from spending years in a small cage, hoed the weeds along the paths exactly as a human staffer did. She piled her weeds along the path just as he did. Her work was messier, but then she had to use a stick, since no one would let her have the only hoe in camp.
Another citified rehabilitant was Supinah, who was devoted to imitation. She carried a parasol, combed her hair, and applied bug repellent. She sawed, hammered, painted, pumped water, and sharpened axes. She came impressively and disturbingly close to lighting a fire in the camp kitchen. The cooks did this in a multistep procedure involving kerosene, and one day the cook stepped out and Supinah stepped in. Having watched the cook many times, she confidently took a burning stick from the still-smoldering breakfast fire. She scooped a cup of kerosene—Russon, who had not watched as carefully as Supinah, took the clear fluid to be water and was not alarmed—and plunged the burning brand into it. By good fortune, Supinah was too fast and the kerosene smothered the flames instead of fueling them. (While Supinah was engaged in these interesting experiments, her tufty little orange infant was clinging to her, or playing nearby. That’s a future firebug I’d keep an eye on.)
Meanwhile, back at the laboratory
In one experiment with captive orangutans, both human children and orangutans saw a human demonstrator get food out of a box by pulling, pushing, or rotating a rod on the box. The children imitated the demonstrator and the apes did not. They tried the orangutans again with a trained orangutan as demonstrator and they still didn’t imitate.
Robert Shumaker and colleagues set up a different test situation with orangutans at the National Zoo. Instead of watching a mysteriously expert demonstrator, these apes watched another orangutan being taught to perform the task. The task, an early stage of a language acquisition study, was to label a food with an abstract symbol by pointing to the symbol with a single finger, not a usual orangutan gesture. The human teacher focused only on the orangutan being taught and ignored the other, lower-ranking orangutans who were observing. Any time the orangutan who was being taught went away for a minute, an observer immediately went over to the apparatus, touched the appropriate symbol with one finger, and then requested the reward by extending a hand or pointing their lips at the teacher.
Shumaker and colleagues suspect that one reason the orangutans imitated the task so readily is that they got to watch a teaching process, rather than simply being wowed by the inexplicable prowess of the expert.
Other forms of social learning
At a police-dog training school in South Africa, 20 litters of German shepherd puppies were bred. Some were born to mothers who had no special training, and some had mothers who were trained to sniff out sachets full of narcotics. The puppies were divided into four groups. One group left their mothers at 6 weeks, as was standard, and one group stayed with their mothers for 12 weeks. The third group stayed with their mother for 12 weeks, and between the ages of 6 and 12 weeks got to see their mother sniffing out and retrieving narcotics sachets and being praised for her work, twice a week. The fourth group also had mothers trained in this work, but since they left her at 6 weeks, they never saw her on the job.
After 6 or 12 weeks all the puppies were put in standard police-dog obedience training, but none had any work with narcotics or retrieving. At 6 months, all the pups were tested for their ability to follow directions from handlers to find and retrieve sachets of narcotics, and scored from 0 to 10. Puppies of untrained mothers did about the same whether they had been with their mothers for 6 weeks or 12 weeks. Puppies who had been with their mothers 6 weeks did the same whether their mothers were trained or untrained.
But the puppies who had stayed with a trained mother for 12 weeks and seen her at work excelled. Four of them scored 9, “the highest recorded for any untrained pups since establishment of the dog school,” gloat the researchers.
Clearly the puppies had learned something from observing their mothers work. The puppies got no rewards when their mothers retrieved narcotics, so operant conditioning is unlikely to have been a factor, and their mothers weren’t there when they were tested, so neither imitation nor social facilitation seem relevant.
There’s nothing to do.
Let’s go hang out on the pier.
Ring-tailed lemurs are prosimians—a group of animals that branched off our family tree before monkeys and apes—and they are not considered bright, although they do possess long and excellently striped tails. A group of lemurs in the Chester Zoo, in England, were found to have an unusual habit—or at least 17 out of 28 of them did. This was the custom of wetting the ends of their tails and licking the water off.
The Chester lemurs live on an island surrounded by a moat, and on one side of the island is a small wooden pier. To get a drink from its tail a lemur goes to the pier, turns, and climbs backward down a pier support until its tail tip is submerged in or floating on the water. Then the lemur climbs back up and licks water off its tail.
No one noticed when the fad began, so no lemur can be singled out as an originator. No lemurs elsewhere have been seen dipping their tails, so the researchers suspect social learning caused this practice to spread through the group. They consider it “unlikely…that each animal which shows the behaviour has independently discovered it for itself, as this would seem to require a lot of lemurs accidentally falling in the water in this, but not in any other, group.”
This is an unnecessary, show-offy way of getting water, since the lemurs can and do lap water from the moat, lap from water dishes, lick moisture from leaves, or dip a cupped hand into the moat. It does not seem to be something baby lemurs necessarily pick up from their mothers or the other way around, since there was no correlation in mother-child pairs.
Sometimes lemurs seemed unclear on how it was done, backing up to the pier and climbing down without getting their tails wet. Baby Grace climbed down repeatedly, getting her tail wet, climbing up again, and then, instead of licking her tail, looked around “as if not knowing what to do next.” Her mother, Claire, then immersed her tail and let Grace help lick the water off. Two years later, Grace was an accomplished tail-drinker.
The researchers end their paper by noting that 2 of the 15 hamadryas baboons in the Zurich Zoo dipped their tails in the moat and drank from their tails; they were watched by the other 13, who never learned to do it. The lemur researchers imply that the math (17 out of 28 lemurs versus 2 out of 15 baboons) favors the prosimians. “Perhaps it is time to re-assess our views on the evolution of primate intelligence, since a baboon is obviously no match for a cognitive lemur.” (On the other hand, I must point out that the adolescent baboons at Zurich, Liba and Kalos, didn’t have a pier to climb down, but had to hang by their hands. So it was harder.)
The most parsimonious explanation of how this habit spread, the researchers say, is stimulus enhancement. Lemurs noting other lemurs messing around the pier suddenly find the pier interesting, spend more time there, and invent tail-dipping. The chance to lick refreshing moat water off another lemur’s tail may also promote interest. On the other hand, it might be imitation, since it’s an odd, unnecessary behavior and since lemurs have been seen approximating the behavior without actually getting their tails wet. Not all lemurs do it identically, so the researchers suggest that it may be program-level imitation, or emulation.
Emulation
Emulation isn’t quite imitation, but maybe it’s even bette
r. When you emulate someone, you don’t copy them exactly, but you try to achieve the same result they have achieved. Such a process is also called program-level imitation.
After all, what’s so great about imitation? Researchers working with dogs write that “social learning in nature does not usually involve the exact copying of the demonstrator’s behaviour. Naïve observers usually want to obtain the same target as the demonstrator and develop their own method to get it.” Is that so dumb? Unless you’re completely without a clue as to how the demonstrator did it, you’re likely to do quite well. You may do better.
The Hungarian researchers looked at how dogs learned to get past a V-shaped wire-mesh fence to get to food or a toy. Many dogs had a hard time with this, particularly if they had to start from outside the V and get something inside the V. They often barked through the fence at the desired object or tried to dig underneath when they couldn’t figure out how to get to it. (Maybe dogs have more practice in trying to get out than trying to get in, suggest the researchers.)
Dogs were allowed to watch a person carry the desired food or toy to the other side of the fence and put it down. Dogs that saw a demonstration were much quicker to get around the fence, whether the demonstrator was their owner or a stranger. They didn’t necessarily go around the same arm of the V as the demonstrator, which argues against simple imitation.
How to crack a safe
Austrian researchers working with captive keas (New Zealand parrots) constructed a fascinating box. It was made of plexiglass so the keas could see a treat within. To open it, birds had to undo three different gadgets: they had to pull a split pin out of a large plastic screw on the lid; unscrew the screw; and poke a bolt out of a latch. Then they had to lift the lid. Two keas were trained to open this box (or “artificial fruit,” as the researchers called it). Other keas, one at a time, got to watch the trained keas open the box in an adjacent aviary numerous times, and then they got to try. The control group got to play with the box without having seen another kea open it. They all loved the box and loved trying to break into it, even when it was empty.
None of the untrained keas managed to open the box in three sessions. Those who got to watch another kea open the box attacked the locking devices, whereas the control birds wasted time nibbling on the frame. Those who had seen another kea open the box all managed to operate at least one of the locking devices, and two of them, Oldred and Green-Silver, opened all three devices (but then didn’t raise the lid). Some of the control birds managed to open one device.
Green-Silver did learn from observation what kind of pulling and poking was called for. The most successful control bird, Blue, “seemed to sample from the whole repertoire of foraging and play actions to see what worked, and only by chance arrived at an efficient means of manipulating the chosen object.” It took her ages to think of pulling on the split pin.
The keas who had a model to copy attacked the locks quicker, worked at them longer, and were better at opening them. The researchers ascribe this to social facilitation (“Here’s a fun project for keas”), to stimulus enhancement (“Apparently the locks are the things that all the hip keas pay attention to”), and to emulation. It is possible, the researchers say, that the trained keas opened the box so fast that the observers couldn’t see how. They didn’t imitate in the sense of “copying…the response topography of the opening technique shown by the models.” They didn’t or couldn’t think, “Okay, so after you pull out the split pin, you grab the outer end of the screw and turn it counterclockwise until it comes out,” but instead thought the equivalent of, “Okay, you mess with those doohickeys up there and somehow pull out the screw.”
Making up your own lesson plan
Karen Pryor and colleagues at an oceanarium in Hawaii used conditioning to teach dolphins to do many entertaining things. The idle idea came of training the performers to invent new tricks. Working with Malia, a rough-toothed porpoise, they rewarded her only when she did something she had never done before. At first Malia had no idea what she was being asked, but after a few days she got it, and session after session came up with new, unexpected, and downright bizarre activities. She did flips in the air, she glided with her tail out of the water, she skidded along the bottom of the tank. Sometimes she seemed so excited at her first session of the day that her trainers were convinced she had thought up new stuff that she couldn’t wait to show them. Amazed, they repeated the experiment with another porpoise, Hou.
Hou, considered a docile and timid porpoise, spent the first few sessions being rewarded for stuff that was not that unusual, but which she hadn’t done before. Pretty soon Hou was stumped. Each time she’d do all the things she’d been rewarded for before, over and over, without praise or reward. What could they possibly want? In her fifteenth and sixteenth sessions, Hou suddenly got it. She quickly began doing new things: slapping the water with her tail, somersaulting in the air, swimming in figure eights, spinning, slapping her tail upside down. Later she invented tricks ranging from sinking head downward to executing fancy jumps. By the thirty-second session “Hou’s aerial behaviors became so complex that, while undoubtedly novel, the behaviors exceeded the power of the observers to discriminate and describe them.” She also invented spitting at her trainer.
Before anyone says this proves how smart dolphins are, Pryor taught pigeons to do the same thing, and they originated such odd acts as lying on their backs, standing with both feet on one wing, and hovering two inches in the air.
What did I just tell you?
It is also possible to learn through being told. This almost never happens in animals due to their poor language skills, and happens in people less often than teachers like to think. The bonobo Kanzi understands a great deal of English. When he was just a little ape, he was playing with tools one day, and decided to unscrew some screws holding a plate over an electrical socket. His close friend, primatologist Sue Savage-Rumbaugh, got upset, and emphatically told him that sockets were dangerous, that something called shocks—electricity—came out of them and could hurt him. He approached the socket with caution, hair standing on end, but it didn’t do anything bad to him. He threw objects at the socket, and nothing bad happened and nothing came out. He began to be skeptical.
Kanzi hid the screwdriver under a blanket. He waited until Savage-Rumbaugh was busy sorting a sheaf of pictures she was going to use to test his comprehension, sneaked the screwdriver out, and inserted it into the socket.
He got a nasty shock. His hair stood straight out from his body. “Waa! Waa!” he shouted and began throwing things at the evil socket, beckoning Savage-Rumbaugh to join the attack.
Kanzi couldn’t really learn this through having it explained because he had no idea what shocks and electricity were, any more than small children do. So he learned by trial and error. He could have taken Savage-Rumbaugh’s word for it, but this would have been unlikely; for this very reason many small children are not allowed to play with screwdrivers. (Also, may I point out, she lied to Kanzi about there being monsters on the roof of the building where the air-conditioning vents are, so Kanzi was not entirely wrong to be skeptical.)
Hardly any animal children have Kanzi’s option of learning about the world by being told, and not every animal child can learn through imitation, but all animal children have some learning methods at their disposal. With any luck, these will help them understand the world and make their way through it. If they are born into a different world than the one in which their forebears evolved, they need not rely only on genetically fixed behaviors to carry them through, for they have ways of coming up with new solutions to the new problems that confront them.
TWO
Learning the Basics: How to Crawl, Walk, Climb, Swim, and Fly
Young California condors often think they’re ready to fly when they’re not. They take off from their cliffside nest, fly a short way, desperately flapping, feet dangling, and plummet into the chaparral below. It’s not rare for a foolish young bird to spend a couple o
f days bumbling around in the chaparral (with food deliveries from its parents) before it makes its way to a clearing where it can take off again. One chick at a nest observed in 1939 spent almost a month on the ground before it could fly back up to its nest. This chick fledged so early that condor experts suggest that it hadn’t really meant to fly in the first place—it merely leaned out too far from the nest cave for a little wing-flapping practice and toppled out.
A FEW MINUTES AFTER IT IS BORN, a salt desert cavy (a South American rodent) can walk, run, and sand-bathe in a coordinated fashion. Most of us took more than a year to walk and run, and still cannot sand-bathe with any degree of mastery.
One important thing that baby animals must learn is how to move from one place to another in the ways appropriate to their species, whether that includes walking, swimming, climbing, or flying. There are innate motor patterns and other clues that help some species more than others and promote some activities more than others.
The things we do that are the most clearly prescribed by our genes are the ones we hardly notice. Like many other animals, we are born knowing how to stretch and yawn and sneeze. But, as anyone who has raised a small child can tell you, we’re not born knowing how to blow our noses. Sneezing may not seem like a big deal, but keeping your airways clear for breathing is vital, and it clearly gives animals a survival edge not to have to stop and learn how it’s done.
Becoming a Tiger: The Education of an Animal Child Page 4