In his book Guns, Germs, and Steel: The Fates of Human Societies, Jared Diamond argues that environmental considerations rather than inherent differences in intellect or genes caused some civilizations to survive longer and prosper more than others. In the book's prologue, Diamond explains that it was a question by a New Guinean politician named Yali that prompted him to research and write the book.
The prologue to Guns, Germs, and Steel is called "Yali's Question." In it, Diamond writes that he was visiting New Guinea as a biologist studying bird evolution. He and Yali were taking a walk along a beach together. Diamond could see that Yali possessed an abundance of charisma, energy, intelligence, and curiosity, albeit in ways that differed from western norms, given that New Guineans had only been exposed to western, industrialized civilization in the last few centuries. When whites arrived, they had centralized governmental authority and brought various tools that New Guineans had never seen before, such as matches, steel axes, clothing, medicines, and other items. The collective word for goods like these to New Guineans was "cargo."
Although many white people thought of native New Guineans as inferior, Diamond, through his exposure to many locals, was well aware that they were "on the average at least as smart as Europeans." That's partly why Yali's question was so thought-provoking to him. Yali asked:
Why is it that you white people developed so much cargo and brought it to New Guinea, but we black people had little cargo of our own?
As Diamond relates, Yali's question was difficult for him to answer. It was true that Europeans, Americans, New Guineans, and other civilizations throughout the world had vastly different lifestyles and histories, but it was not a simple matter to account for these discrepancies. Diamond explains on his website:
The answer depends on a synthesis of four bodies of information, in the fields of social science, botany, zoology, and microbiology, applied to findings of archaeology, linguistics, and human genetics.
Ultimately it took Diamond 25 years to research and write Guns, Germs, and Steel as an answer to Yali's question.