Why is it that Europeans ended up conquering so much of the world? Or, as one of Diamond’s New Guinean friends asks him, why do they have all the “cargo”? Despite all the contrary evidence from anthropology and human biology, many persist in attributing the differing political and economic successes of the world’s peoples to biological, “racial” differences. Others appeal to cultural differences or to historical contingency. But Diamond sees the fundamental causes as environmental, resting ultimately on ecological differences between the continents. An extended argument for this, Guns, Germs and Steel is nothing less than a history of Homo sapiens on a scale of continents and millennia.
Diamond begins with a survey of human pre-history, covering the spread of humans around the world down to 11000 BC. He then introduces Polynesia as a “natural experiment”, an illustration on a smaller scale of his overall thesis. In the Polynesian exploration and settlement of the Pacific, settlers from the one cultural and ethnic background ended up in vastly different environments, ranging from continental New Zealand, through volcanic islands of various sizes, to barren atolls and remote Easter Island. Hunter-gatherer societies eventuated on some islands — and sophisticated states and proto-empires on others.
As an exemplar of contact between different societies, Diamond chooses the meeting of the Spanish conquistador Pizarro and the Inca Atahuallpa at Cajamarca in 1532. This resulted in Pizarro’s victory, despite a numerical disadvantage, and the capture of Atahuallpa. The proximate causes of this were germs, technology (guns and steel weapons, ships), domestic animals (horses), and writing. Hence the title.