In 1908, a clay disk bearing writing was excavated on the Greek island Phaistos. The disk bears forty-five symbols, probably of a syllabary, which were stamped into the clay. Nobody has yet deciphered this writing. Archaeologists believe it may have been the first printing system in the world but that it dropped out of use. A similar printing system did not emerge elsewhere until 2,500 years later and 3,100 years later in Europe.

Some inventions happen because people need a technology and set out to create it. Other inventions come about because people tinker and experiment and create something for which they only later find a use. Diamond argues that this latter process is more common in history. He also believes that invention depends less on the work of a few rare geniuses than on the accumulated efforts of many people who improve on the work of those who came before them. Most famous inventors, such as James Watt and Thomas Edison, were improving on similar, less useful inventions. The likes of Watt and Edison simply managed to push inventions to a level that made them usable on a mass scale.

People often assume that the inhabitants of some continents are predisposed to be technologically backward. Diamond feels that such assumptions are speculative and that they neglect to take into account that native societies are highly varied. Some individuals and tribes adopt new technologies rapidly when they are introduced even when their close neighbors do not. Diamond believes it is impossible to assume that people across whole continents are systematically better or worse at creating and adopting new technologies consistently over many millennia.

Technological progress happens more and more rapidly over time. The Industrial Revolution brought more new technologies than the Bronze Age did, which had brought more new technologies than the advancements before it. Technological advancements depend on the mastery of basic problems and the development of complementary technologies. Sustainable printing depended on the existence of paper and moveable type, for example, which were imported to Europe from China. The maker of the early printing system using the Phaistos disk did not have the use of such technologies. Because of that, his system was less practical, which may explain why it dropped out of use.

The development of food production in 8500 BCE resulted in a major jump in technology development. Diamond theorizes that this is because people became sedentary, so they were able to acquire more possessions. He also thinks that the ability to store and manage food supplies created a situation that allowed people to specialize in jobs other than obtaining food. Technologies then spread to the areas they could easily reach, thus creating more opportunities for people to build on them.

Greater land area gives the inhabitants of a given continent a substantial advantage because the continent supports more societies that presumably invent more new technology. Eurasia, the largest continent, developed more technology than did the Americas. Sub-Saharan Africa, the third largest landmass, and Australia, the smallest, followed in turn.