Let me briefly offer two examples of how these issues may be tackled. The first concerns a study at the Burgers’ Zoo itself. Conflicts in the colony rarely remained restricted to the original two contestants, since chimps have a tendency to draw others into the fray. Sometimes ten or more chimps would be running around, threatening and chasing one another, uttering high-pitched screams that could be heard a mile away. Naturally, every contestant tried to get as many allies on his or her side as possible. When I analyzed hundreds of videotaped incidents (a new technique at the time!), I found that the chimpanzees who were losing the battle beseeched their friends by stretching out an open hand to them. They tried to recruit support in order to turn things around. When it came to the friends of their enemies, however, they went out of their way to appease them by putting an arm around them and kissing their face or shoulder. Instead of begging for assistance, they sought to neutralize them.6
To know the friends of your opponents takes experience. It implies that individual A is aware not only of her own relations with B and C but also of the relation between B and C. I dubbed this triadic awareness, since it reflects knowledge of the entire ABC triangle. It is the same with us, when we realize who is married to whom, who is a son of whom, or who is the employer of whom. Human society could not function without triadic awareness.7
The second example concerns wild chimpanzees. It is well known that there is no obvious connection between a male’s rank and his size—the biggest, meanest male does not automatically reach the top. A small male with the right friends also has a shot at the alpha position. This is why male chimps put so much effort into alliance formation. In an analysis of years of data collected at Gombe, a relatively small alpha male spent far more time grooming others than did larger males in the same position. Apparently, the more a male’s position depends on support from third parties, the more energy he needs to invest into diplomacy, such as grooming.8 In a study in the Mahale Mountains, not far from Gombe, Toshisada Nishida and his team of Japanese scientists observed an alpha male with an exceptionally long tenure of more than a decade. This male developed a “bribery” system, selectively sharing prized monkey meat with his loyal allies, while denying such favors to his rivals.9
Years after Chimpanzee Politics, these studies confirmed the tit-for-tat deal making that I had implied. But even while I was writing my book, supportive data were being gathered. Unknown to me, Nishida had followed an older male at Mahale, named Kalunde, who had moved himself into a key position by playing off younger, competitive males against one another. These young males sought Kalunde’s support, which he handed out rather erratically, making himself indispensable to the advancement of any one of them. Being the dethroned alpha male, Kalunde made a comeback of sorts, but like Yeroen, he didn’t claim the top position for himself. He rather acted as power behind the scenes. The situation was so eerily similar to the saga I had described that I was thrilled, two decades later, to meet Kalunde in person. Toshi, as the late Nishida was known to his friends, invited me for some fieldwork, which I gladly accepted. He was one of the world’s greatest chimpanzee experts, and it was a treat to follow him around through the jungle.
Living in the camp near Lake Tanganyika, one realizes that running water, electricity, toilets, and telephones are greatly overrated. It is entirely possible to survive without them. Every day the goal was to get up early, eat a quick breakfast, and get going before the sun rose. The chimps would have to be found, and the camp had several trackers to assist us. Fortunately, chimps are incredibly noisy, which makes them easy to locate. Chimps do not travel all in a single group but are spread out over separately traveling “parties” of just a few individuals each. In an environment with low visibility, they rely heavily on vocalizations to stay in touch. Following an adult male, for example, you continuously see him stop, cock his head, and listen to others in the distance. You see him decide how to respond, by replying with his own calls, silently moving toward the source (sometimes in such a hurry that you are left struggling through tangled vines), or continue on his merry way as if what he just heard lacked any relevance.
By then Kalunde was the oldest male, only about half the size of a prime adult male. Being around forty, he had shrunk. But despite his advanced age, he was still into political games, frequently accompanying and grooming the beta male until alpha returned from a long period of absence. Alpha had traveled to the fringes of the community territory, escorting a sexually receptive female. High-ranking males may go for weeks on end “on safari” with a female, as it is known, in order to avoid competition. I knew about alpha’s unexpected return only because Toshi told me in the evening, but I had noticed great agitation in the males that I had been following the whole day. They were restless, running up and down the hills, totally exhausting me. Alpha’s characteristic hooting and drumming on empty trees had announced his return, making everyone hypernervous. In the following days, it was fascinating to see Kalunde switching camps. One moment he would be grooming the returning alpha; the next he’d be hanging out with the beta male, as if trying to decide which side he should be on. He offered the perfect illustration of a tactic that Toshi had dubbed “allegiance fickleness.”10
You can imagine that we had much to talk about, especially comparing wild versus zoo chimps. Obviously, there are major differences, but it is not as simple as some people think, especially those who wonder why one would study captive animals at all. The goals of both types of research are quite different, and we need both. Fieldwork is essential to understanding the natural social life of any animal. For anyone who wants to know how and why their typical behavior evolved, there is no substitute for observing them in their natural habitat. I have visited many field sites, from capuchin monkeys in Costa Rica and woolly spider monkeys in Brazil to orangutans in Sumatra, baboons in Kenya, and Tibetan macaques in China. I find it very informative to see the ecology of wild primates and to hear from colleagues what sort of issues they are fascinated by. Fieldwork is nowadays very systematic and scientific. The days of a few scribbled observations in a notebook are gone. Data collection is continuous and systematic, typed into handheld digital devices, and complemented with fecal and urine samples that allow DNA analysis and hormone assays. All this hard, sweaty work has enormously advanced our understanding of wild animal societies.
Yet in order to get at behavioral details and the cognition behind them, we need more than fieldwork. No one would try to measure a child’s intelligence by watching him run around in the schoolyard with his friends. Mere observation doesn’t offer much of a peek into the child’s mind. Instead, we bring the child into a room and present him with a coloring task or a computer game, let her stack wooden blocks, ask questions, and so on. This is how we measure human cognition, and it is also the best way to determine how smart apes are. Fieldwork offers hints and suggestions but rarely allows firm conclusions. One may encounter wild chimpanzees who crack nuts with stones, for example, but it is impossible to know how they discovered this technique or how they learn it from one another. For this, we need carefully controlled experiments on na?ve chimpanzees who receive nuts and stones for the first time.