How does Yali describe the influence whites had on New Guineans and their society in Guns, Germs, and Steel?

In Guns, Germs, and Steel: The Fates of Human Societies, author Jared Diamond argues that environmental differences rather than cultural or genetic differences are responsible for some civilizations accumulating wealth, power, and advanced technology rather than others. In the prologue called "Yali's Question," Diamond explains that it was due to a conversation with a New Guinean politician named Yali and a particular question that Yali posed that prompted him to write the book.
Diamond and Yali meet one another while walking on a beach in New Guinea, and it is then that Yali asks his question, "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?" By "cargo," Yali refers to the material goods that white people brought and New Guineans valued such as steel axes, matches, clothing, medicine, and other items.
This question is the only direct quote from Yali in the book. However, during his description of their conversation, Diamond explains the influence that the whites had on New Guineans and their society. When the whites arrived, New Guineans were still using stone implements and living in villages without any central authority. The whites "imposed centralized government" and brought the material things that enthralled the New Guineans. They also considered themselves superior to the local people, and whites maintained a much higher standard of living than the native New Guineans. Diamond writes of Yali:

He and I both knew perfectly well that New Guineans are on the average at least as smart as Europeans.

So the power and material wealth of the whites, despite the equal intelligence of the New Guineans, is what prompts Yali's question and the book-length answer that Diamond provides.
http://www.jareddiamond.org/Jared_Diamond/Guns,_Germs,_and_Steel.html