Pacific Island cultures are useful for testing theories of nature and nurture, as Jared Diamond emphasized in Guns, Germs, and Steel:

Moriori and Maori constitutes a brief, small-scale natural experiment that tests how environments affect human societies. Before you read a whole book examining environmental effects on a very large scale— effects on human societies around the world for the last 13,000 years—you might reasonably want assurance, from smaller tests, that such effects really are significant. If you were a laboratory scientist studying rats, you might perform such a test by taking one rat colony, distributing groups of those ancestral rats among many cages with differing environments, and coming back many rat generations later to see what had happened. Of course, such purposeful experiments cannot be carried out on human societies. Instead, scientists must look for “natural experiments,” in which something similar befell humans in the past. Such an experiment unfolded during the settlement of Polynesia. Scattered over the Pacific Ocean beyond New Guinea and Melanesia are thousands of islands differing greatly in area, isolation, elevation, climate, productivity, and geological and biological resources. For most of human history those islands lay far beyond the reach of watercraft.

Diamond begins with the story of how in 1835, the teeming masses warlike Maoris of New Zealand invaded and conquered their pacifist hunter-gatherer cousins, the Moriori of the remote and chilly Chatham Islands. Polynesian crops wouldn’t grow on the Chatham Islands, so the settlers had centuries before become foragers. If the old stories are true, the Moriori may have been one of the few pacifist cultures in human history.

GG&S is a rather dry book, so here’s the tale as told in David Mitchell’s novel Cloud Atlas: