The lesson to me is to be a racially uniform and natural resource rich nation.
It's difficult or even impossible to translate that into different country, but I'd argue each bit has an effect over long period of time. US has become so antagonistic over the years it's hard to see it ever growing out of it. And in smaller scale of course, US must have similar kind of environments. But the cultural norms are such that it's not really a joint goal of the people to have it for everyone. It's a behavioural dilemma since in order to create such culture it has to reciprocated and seen as the "better way", but that takes generations to happen. By believing it can't be done it's kind of a self-fulfilling prophecy. Our egos are too fixated on our own habits that learning to look life at different perspective is made impossible. And when happiness can be directly measured in how many dollars you have, who could convince people otherwise.
This is not possible for either countries with low income or large cultural or racial diversity because there is big difference of opinion on what is good for society