"Ours is not really a planet of the apes. Rather, it is a planet overwhelmingly populated by one ape species: us. The other 'great apes' include chimpanzees, bonobos, gorillas and orangutans, none of which are abundant." A Wall Street Journal book review.

‘The New Chimpanzee’ Review: Mysteries of the Chimpanzees. Unusual among nonhuman primates, male chimpanzees are considerably more social than females.

By David Barash March 9, 2018

Ours is not really a planet of the apes. Rather, it is a planet overwhelmingly populated by one ape species: us. The other “great apes” include chimpanzees, bonobos, gorillas and orangutans, none of which are abundant.

There are many reasons to be interested in these creatures, not least that they are fascinating members of life’s panoply, worth knowing, observing and preserving for their own sakes. Long before biology’s evolution revolution, people recognized kinship with them—and with chimpanzees in particular. Regrettably, all of the great apes are now at risk of extinction, us included. It would not be in our interest to let the chimps fall where they may.

THE NEW CHIMPANZEE

By Craig Stanford

Harvard, 274 pages, $35

There is something undeniably human-like about chimps, and chimp-like about humans, all of which is to be expected given that we share nearly 99% of our nuclear DNA with them (and with bonobos). Moreover, all three species—humans, chimps and bonobos—are more closely related to one another than to gorillas or orangutans. This fact has led Jared Diamond, of the University of California, Los Angeles, to label Homo sapiens the third chimpanzee. It has also led biologists, even before DNA sequencing was routine, to spend a great deal of time studying chimps.

The pioneer researchers in the field include Jane Goodall and three Japanese scientists little-known in the West but renowned among primatologists for their work primarily in the 1960s and ’70s: Junichiro Itani, Kinji Imanishi and Toshisada Nishida. Since this early work, our knowledge of chimpanzees has continued to expand thanks to an array of doughty field workers. Among the most productive has been Craig Stanford, whose book, “The New Chimpanzee,” is suitably subtitled “A Twenty-First-Century Portrait of Our Closest Kin.” Mr. Stanford began studying chimpanzees at Ms. Goodall’s now-famous Gombe Stream National Park in Tanzania more than three decades ago.

Mr. Stanford, a professor of biological sciences and anthropology at the University of Southern California, is a talented and fluent writer as well as an accomplished researcher. “My hope,” he writes, “is that readers will appreciate chimpanzees for what they are—not underevolved humans or caricatures of ourselves, but perhaps the most interesting of all the species of nonhuman animals with which we share our planet. The gift of the chimpanzee is the vista we are offered of ourselves. It is a gift at risk of disappearing as we destroy the chimpanzees’ natural world and drive them toward extinction.” I would add that the most valuable component of that vista is the glimpse we get not of ourselves but of those chimps for their own sake.

Researchers have unearthed remarkable cognitive abilities among chimpanzees, but such discoveries have been made using captive animals, either in labs or zoos. The findings of Mr. Stanford and his colleagues involve studying these animals in their natural environments, which is the only situation in which they can reveal the diversity and depth of their behavioral repertoire, notably as it reflects the impact of ecological cues (especially the location of fruiting trees) as well as the presence of competing social groups.

Ms. Goodall discovered that chimps use simple tools (including sticks for “fishing” termites out of their mounds) and occasionally hunt, ritually sharing the meat thereby obtained; they also engage in a form of intergroup aggression sometimes called (misleadingly, since it is altogether different from the human phenomenon) warfare. Mr. Stanford’s book expands upon what we have learned in the four decades since Ms. Goodall first began her field research. His chapter titles provide an outline.

In “Fission, Fusion, and Food,” we learn that the earlier conception that chimps live in chaotic, ever-changing social groups is not valid. Rather, they occupy “communities” whose constituents sometimes combine, sometimes split up, and are always influenced by the availability of food and estrus females. Unusual among nonhuman primates, males are considerably more social than females. “We now think,” Mr. Stanford writes, “that male cooperation is based mainly on the shared benefits of working together, with kin selection playing some role as well.” Elsewhere, he writes that alliances “tip the balance away from more powerful, lone actors in favor of lower-ranking males who team up briefly. In my own field studies, there was always a single alpha male, but his power at a given moment was highly dependent on those around him.”

In “Politics Is War Without Bloodshed,” a version of Clausewitz’s maxim that war is politics by other means, the reader is granted insight into the ways in which chimps—especially those highly social but no less scheming males—achieve dominance and, with it, reproductive success: “Some males are inveterate social climbers, cleverly serving their own ends by ingratiating themselves with high-ranking males and females. Others rely more on brute intimidation, which does not necessarily carry the day. And then there are males who seem to care little about their social status and are content to live out their lives on the edges of the struggle.” Of the nearly trite concept of alpha males, Mr. Stanford writes that “the most famous of all alphas in recorded chimpanzee history,” a chimp named Mahale alpha Ntologi, who was observed in Tanzania, “shared meat liberally as he rose in rank. But . . . once he had achieved alpha status, his generosity dropped, and he began sharing meat mainly with those whose political support he still needed most.” To his credit, the author refrains from pointing out human parallels.

The chapter “War for Peace” is a riveting discussion of intergroup aggression, in which males band together to ambush and occasionally raid neighboring groups, often with gruesome and lethal results. Chimps are the only primates, other than humans, that routinely kill members of the same species over access to resources. Adult females as well as males sometimes commit infanticide. As Frans de Waal demonstrated in impressive detail, chimps also engage in ritualized postconflict reconciliation—at least in captivity.

When it comes to “Sex and Reproduction,” things are comparably contradictory, with a degree of sexual free-for-all combined with exclusive consortships, in which females may cycle rapidly between apparent promiscuity and genuine sexual choosiness. We also learn about hunting, a cooperative endeavor whose goal (at least for males) appears to be enhanced mating opportunities as well as coalition-building. “We know that males use meat for a variety of political purposes. . . . One aspect of male manipulation of others was the use of meat to entice females to mate with them.” Also notable is the cultural transmission of certain behaviors, especially the use of tools to obtain food.

Despite its relative brevity, “The New Chimpanzee” is a remarkably thorough account of our current knowledge about free-living chimpanzees. Although it is tempting to try to use this knowledge to better understand human evolution and human nature, in many respects—notably, their inclinations toward violence—chimps are quite different from us. They may fight over females and territory using their hands and teeth, but we will fight for many additional reasons with the use of weapons, from clubs and knives to nuclear weapons.

My own inclination, when considering chimpanzees or any other animal, is to follow the advice of the early-20th-century naturalist Henry Beston : “The animal shall not be measured by man. In a world older and more complete than ours they move finished and complete, gifted with extensions of the senses we have lost or never attained, living by voices we shall never hear. They are not brethren, they are not underlings; they are other nations, caught with ourselves in the net of life and time, fellow prisoners of the splendor and travail of the earth.”

—Mr. Barash is an emeritus professor at the University of Washington. His next book is “Through a Glass Brightly: Using Science to See Our Species as We Really Are.”