> Evidence suggests ~30% of people are content to be
worse off in order to inflict a larger loss upon others. This paper makes for rather grim reading but imho provides a very useful heuristic for understanding the political enfironment in an era of mass communication.
Pinning this on human psychology is ignoring how the game is set up. If you structure something in such a way that the person who gets the most points wins and gets a prize, a move that causes you to lose one point but causes your only opponent to lose two points will put you ahead. That's arithmetic, not psychology.
The issue, then, is when we allow things to be structured that way -- as zero sum games. Instead what we should be doing is stamping out anything that fosters artificial scarcity.
Moreover, as the paper points out, that's what happens in dyadic systems. Which is to say, two party systems. If you have the option to cost yourself a point but cost one of your opponents two points, that's an advantageous move in a two-party system, but not in a five-party system even with a zero-sum game, because then you've cost yourself a point against three of the four other parties. So if you want to get rid of that, have your state adopt score voting (specifically score voting, not IRV or any of that mess) instead of the existing voting system which mathematically constrains us to a two-party system.