There's a ton of prisoner's dilemma-inspired research into this that has many types of answers to this question. Not perfect answers (perfect equality is not at

There's a ton of prisoner's dilemma-inspired research into this that has many types of answers to this question. Not perfect answers (perfect equality is not attainable), but interesting options still. For example, as soon as you have a system that allows for punishing each other, then people turn out to be willing to punish cheaters even at their own expense. And the addition of that to group dynamics tends to make it self-stabilizing. If many in the group can chip in to gravely punish a cheater at a small cost to themselves, the group can become quite stable and egalitarian. But I can also see how that can be stifling and oppressive-by-majority (think small-minded villages).