Diamond argues that the fate of human societies has been largely determined by geographic factors. The availability of domesticable plants and animals, the orientation of continental axes, and the presence of natural barriers have all played a crucial role in shaping the development of civilizations. This idea challenges the notion that cultural or racial differences are the primary drivers of societal success.

The development of agriculture is a central theme in "Guns, Germs, and Steel." Diamond explains how the domestication of plants and animals allowed for the creation of surplus food, which in turn led to population growth, social stratification, and technological advancements. The ability to produce and store food was a key factor in the rise of complex societies and the spread of human populations.

Diamond highlights the importance of technological advancements in shaping human history. The development of tools, weapons, and other innovations allowed societies to conquer and dominate others. The spread of technology was influenced by factors such as trade, communication, and the movement of people. This idea underscores the interconnectedness of human societies and the role of innovation in driving progress.