In the largest published PDG [prison dilemma game] experiment (Rapoport & Chammah 1965), almost 50 percent of strategy choices were cooperative, and even in experiments using one-shot PDGs, many players cooperate, to their mutual advantage.
This is the PGM:
If A and B each betray the other, each of them serves 2 years in prison If A betrays B but B remains silent, A will be set free and B will serve 3 years in prison (and vice versa) If A and B both remain silent, both of them will only serve 1 year in prison (on the lesser charge).
So, we go against our interest like 50% of the time.
Let us assume people are like that in "life", that its a sound experiment, that it does reflect our social interactions.
So, why does everyone expect NAY encourage, the self interested voter?