board · 732 × 588grid · on
Each person carries a group colour and two inherited traits: cooperate with the same group, and cooperate with different groups. Those two bits create altruists, ethnocentrics, egoists, and cosmopolitans.
The board and strategy graph now share one colour key: purple altruists, orange ethnocentrics, slate egoists, and cyan cosmopolitans. Shape reinforces the same distinction, while Inspect reveals each person's inherited group. Energy, reproduction, death, and mutation make the population evolve.