The Third Chimpanzee — The Evolution and Future of the Human Animal

The Third Chimpanzee

We think of chimpanzees as our closest relatives, separated from us by an enormous gulf of intelligence, language, and culture. Jared Diamond’s opening argument in The Third Chimpanzee reframes this assumption with a single genetic fact: human DNA differs from that of the common chimpanzee by only 1.6%. We differ from gorillas by more. If we were classifying animals purely by genetic distance, humans would be classified as a third species of chimpanzee — the third chimpanzee.

This reframing does substantial intellectual work. It forces the question: what, exactly, makes the 1.6% difference so consequential? What does that genetic distance account for? Diamond’s answer is the book’s subject: language, art, agriculture, technology, religion, drugs, genocide, and environmental destruction — the full catalog of what is distinctively human, both magnificent and catastrophic.

The Great Leap Forward

Diamond proposes that the distinctively human cognitive capacities — language, art, symbolic thought — emerged relatively suddenly, around 50,000 years ago, in what he calls the Great Leap Forward. Before that point, human stone tools had changed little for a million years. After it, tool technology, art, long-distance trade, and evidence of symbolic behavior appear in the archaeological record with striking rapidity. Diamond speculates that a single genetic mutation affecting the structure of the larynx or the neural architecture of language may have triggered this transformation.

The Dark Side of the Leap

The same cognitive capacities that produced art and language also produced genocide and ecological destruction. Diamond examines both as evolutionary phenomena with deep roots in primate behavior. Chimpanzees conduct lethal raids on neighboring groups; humans have simply scaled this tendency up. The megafauna extinctions that followed human arrival in Australia, the Americas, and on oceanic islands represent the first instances of a pattern that has accelerated ever since.

Anticipating the Later Work

The Third Chimpanzee anticipates the larger arguments of Guns, Germs, and Steel and Collapse — the uneven geographical distribution of domesticable plants and animals, the role of epidemic disease in conquest, the environmental roots of societal failure. Reading it as part of Diamond’s larger project reveals how consistently his thinking has been organized around a single underlying question: what does our evolutionary and environmental history tell us about how we got here, and where we are going?

Diamond’s Unusual Path to the Book

What makes The Third Chimpanzee distinctive among popular science books is the breadth of expertise its author brought to it. Jared Diamond is not a single-discipline specialist who wandered into popularization. He trained in physiology and biophysics, taught at UCLA, and built a parallel career as a field ornithologist studying the birds of New Guinea, work that gave him decades of firsthand experience with traditional societies and tropical ecology. That combination — laboratory physiology, evolutionary biology, geography, and ethnographic fieldwork — is why the book can move credibly from the genetics of human-chimp divergence to the dynamics of language acquisition to the patterns of first contact between expanding and isolated peoples. Few writers could connect those domains, and the connections are the book’s principal pleasure.

The book also has an interesting publication identity. It first appeared in Britain in 1991 and won both the Rhône-Poulenc Prize for science books and the Los Angeles Times Book Prize. Its American edition followed, and for many readers it served as the introduction to a mind they would later encounter in Guns, Germs, and Steel, the 1997 book that won Diamond the Pulitzer Prize and made him a household name. Read in sequence, the two books reveal how steadily Diamond’s central question — why human history unfolded as it did, and what biology and geography contributed to that unfolding — was already taking shape years before the more famous synthesis.

Where the Argument Has Aged

A responsible reading of The Third Chimpanzee today should hold parts of it at arm’s length. The chapters drawing on evolutionary psychology, particularly the material on sexual selection, mate choice, and the supposed adaptive logic of human behaviors, rest on a body of theory that subsequent research has complicated and in places contradicted. Diamond writes these sections with the same confidence he brings to the genetics, but the confidence is not always equally warranted, and readers familiar with later debates in the field will notice. This does not undermine the book’s spine — the genetic kinship of humans and chimpanzees, the archaeological evidence for the Great Leap Forward, the documented pattern of megafaunal extinction following human arrival — which has largely held up. It simply means the book is best read as a provocative, wide-angle synthesis from a particular moment in the science rather than as settled fact on every page. Approached that way, it remains one of the most stimulating entry points into questions about what we are and where we came from.

Who Should Read It

The Third Chimpanzee rewards the curious generalist — the reader who wants a single book that connects genetics, archaeology, linguistics, and ecology rather than burrowing into any one of them. It is an ideal starting point for anyone planning to read Guns, Germs, and Steel afterward, because it lays out the questions that the later book answers more systematically. Newcomers to evolutionary biology will find Diamond an unusually clear and companionable guide, fond of vivid examples and willing to follow an argument into uncomfortable territory. Specialists, by contrast, may find individual chapters too brisk, since the book’s breadth is purchased at the cost of depth on any single subject. The best way to approach it is as an invitation to think across disciplinary boundaries: read it for the connections it draws, keep a skeptical eye on the evolutionary-psychology passages, and let it send you toward the more focused works — Diamond’s own and others’ — that each chapter gestures toward.

Our rating: 4.3/5 — An ambitious, provocative, and often uncomfortable examination of what evolutionary biology reveals about the full range of human behavior, from art to genocide.