Very interesting. I was under the impression that most games, either ended in a near-50-50 split, or one party rejected the offer. But apparently (and this shows how behind I am on the literature) some 1995 study offers conflicting evidence, and several follow-up studies offer more conflicting evidence.
Can't say I'm entirely surprised. The more I learn about the brain, the more I realize how plastic it is. I always wondered what would happen if they tried to pull some of those behavioral finance tests on seasoned trading and investing pros.
In any case, I'm sure the article's conclusion would make even David Graeber proud:
"
Because Machiguengan culture had a different history, their gut feeling about what was fair was distinctly their own. In the small-scale societies with a strong culture of gift-giving, yet another conception of fairness prevailed. There, generous financial offers were turned down because people’s minds had been shaped by a cultural norm that taught them that the acceptance of generous gifts brought burdensome obligations. Our economies hadn’t been shaped by our sense of fairness; it was the other way around."