What is Jared Diamond's thesis in Guns, Germs, and Steel?
The central argument in Guns, Germs and Steel by Jared Diamond concerns why some cultures have dominated others. Historians, thinkers, and leaders have perennially asked this question, and the usual theories have included "geography," "climate," and sometimes "race." But Diamond looks at evidence of how geographical continuity across similar climates supported superior agriculture and weaponry. Societies that were similar enough in climate worked together over centuries to create a synergy in technological innovation that, when combined with communication and trade, produced superior technology.
At the core of his thesis is the idea that human knowledge has built on itself in steps, but communication between civilizations happened far more efficiently from East to West and in temperate climates. The rise of civilization in the form of agriculture helped some societies, notably Western European ones, rely on wheat as a consistent protein source. Because the temperate climate of Western and Eastern Europe, and to some degree Russia, was consistent, wheat could be traded, and there was a continuity of goods across huge distances, linking disparate cultures. This allowed traders and others to learn from one another and share technologies. Due to the production of a stable crop (wheat, and to a similar degree in the East, rice), there was more leisure time to develop technologies, and the production of wheat helped create large urban centers (cities) where task and job differentiation blossomed.
The technology that allowed Europeans to dominate less "developed" nations, such as South, Central, and North American indigenous nations and Africans, was in weaponry. Steel changed the game, and guns made weapons like spears, knives, and bows virtually useless in battle. South, Central, and North American natives and Africans did not have the same East-West exchange of knowledge (as their continents were oriented more from North to South). The continuum of technology exchange from North to South meant radically different climates, inconsistent food crops, and difficulty with trade over vast distances—all of which kept cultural and information exchange limited in a North to South orientation.
Diamond points out that guns and steel won wars, but of course, the diseases of Western countries also wiped out millions of people around the world.