Carel van Schaik—a Dutch primatologist who once was a fellow student of mine and whose field site on Sumatra I visited—followed wild males right before they went to bed in their self-made nests high up in the trees. He recorded over a thousand whooping calls made by these males before nightfall. These loud calls may last for up to four minutes, and all orangs around pay close attention, because the dominant male (the only fully grown male with well-developed cheek pads, or flanges) is a figure to be reckoned with. There is usually only one such male in a given area of the forest.
Carel found that the direction in which adult males call before going to sleep predicts their travel path the next day. The calls contain this information even if the direction changes from day to day. Females adjust their own routes to the male’s, such that sexually receptive females may approach him, and other females know where to find him in case they are being harassed by adolescent males. (Female orangutans generally prefer the dominant male.) Although Carel recognizes the limitations of a field study, his data imply that orangutans know where they will be going and vocally announce their plan at least twelve hours before its execution.19
Neuroscience may one day resolve how planning takes place. The first hints are coming from the hippocampus, which has long been known to be vital both for memory and for future orientation. The devastating effects of Alzheimer’s typically begin with degeneration of this part of the brain. As with all major brain areas, however, the human hippocampus is far from unique. Rats have a similar structure, which has been intensely studied. After a maze task, these rodents keep replaying their experiences in this brain region, either during sleep or sitting still while awake. Using brain waves to detect what kind of maze paths the rats are rehearsing in their heads, scientists found that more is going on than a consolidation of past experiences. The hippocampus seems also engaged in the exploration of maze paths that the rats have not (yet) taken. Since humans, too, show hippocampal activity while imagining the future, it has been suggested that rats and humans relate to the past, present, and future in homologous ways.20 This realization, as well as the accumulated primate and bird evidence for future orientation, has swayed the opinion of several skeptics, who used to think that only humans show mental time travel. We are moving ever closer to Darwin’s continuity stance, according to which the human-animal difference is one of degree, not kind.21
Animal Willpower
A French politician accused of sexual assault was said to have acted like a “randy chimpanzee.”22 How insulting—to the ape! As soon as humans let their impulses run free, we rush to compare them with animals. But as the above descriptions show, rather than give in to sexual desires, chimps have sufficient emotional control to either refrain from them or to arrange privacy first. It all boils down to the social hierarchy, which is one giant behavioral regulator. If everyone were to act the way they wanted, any hierarchy would fall apart. It is built on restraint. Since social ladders are present in species from fish and frogs to baboons and chickens, self-control is an age-old feature of animal societies.
A famous anecdote comes from the early days in Gombe Stream, when chimpanzees still received bananas from humans. The Dutch primatologist Frans Plooij observed an adult male approach the feeding box, which humans could unlock from a distance. Each individual chimpanzee had been put on a strict quota. The unlocking mechanism made a distinctive click, which announced the availability of fruits. But alas, at the very moment that this male heard the click and got lucky, a dominant male appeared on the scene. What to do now? The first male acted as if nothing were the matter. Rather than open the box—and lose his bananas—he sat down at a distance. No dummy either, the dominant male strolled away from the scene. But as soon as he was out of sight, he peeked around a tree trunk to see what the first male was up to. He thus noticed that the other opened the box and quickly relieved him of his prize.
One reconstruction of this sequence is that the dominant male got suspicious since he felt that the other was acting odd. Hence his decision to keep an eye on him. Some have even suggested multiple layers of intentionality: first, that the dominant male suspected that the first male was trying to give the impression that the lid was still locked; second, that the dominant let the other think that he hadn’t noticed.23 If true, this would be a deceptive mind game more complex than most experts are willing to give apes credit for. For me, however, the interesting part is the patience and restraint both males showed. They suppressed the impulse to open the box in each other’s presence, even though it contained a highly desirable food that was rarely available.
It is easy to see inhibitions at work in our pets, such as a cat who spots a chipmunk. Instead of going after the little rodent right away, she makes a wide detour, with her body sleekly pressed against the ground, to arrive at a hiding spot from which she can pounce on her unsuspecting prey. Or take the big dog who lets puppies jump all over him, bite his tail, and disturb his sleep without a single growl of protest. While restraint is apparent to anyone in daily contact with animals, Western thought hardly recognizes the ability. Traditionally, animals are depicted as slaves of their emotions. It all goes back to the dichotomy of animals as “wild” and humans as “civilized.” Being wild implies being undisciplined, crazy even, without holding back. Being civilized, in contrast, refers to exercising the well-mannered restraint that humans are capable of under favorable circumstances. This dichotomy lurks behind almost every debate about what makes us human, so much so that whenever humans behave badly, we call them “animals.”
Desmond Morris once told me an amusing story to drive this point home. At the time Desmond was working at the London Zoo, which still held tea parties in the ape house with the public looking on. Gathered on chairs around a table, the apes had been trained to use bowls, spoons, cups, and a teapot. Naturally, this equipment posed no problem for these tool-using animals. Unfortunately, over time the apes became too polished and their performance too perfect for the English public, for whom high tea constitutes the peak of civilization. When the public tea parties began to threaten the human ego, something had to be done. The apes were retrained to spill the tea, throw food around, drink from the teapot’s spout, and pop the cups into the bowl as soon as the keeper turned his back. The public loved it! The apes were wild and naughty, as they were supposed to be.24