If agents in a vast universe use non-causal decision theories, one agent's choice to fund a "consensus good" provides evidence that their correlated copies across the multiverse will do the same. This turns a small personal sacrifice into a cosmic-scale collective action, solving cooperation problems without a central enforcer.

In economic games, groups where members can punish others for not contributing to the collective good quickly establish strong cooperative norms and thrive. In contrast, groups without a punishment mechanism collapse as individuals act in their own self-interest, causing members to ultimately migrate to the more successful, punishing society.

In program equilibrium, players submit computer programs instead of actions. These programs can read each other's source code, allowing them to verify cooperative intent and overcome dilemmas like the Prisoner's Dilemma, which is impossible in standard game theory.

Contrary to media portrayals, crises don't typically cause selfish panic. Instead, the shared threat creates a powerful 'emergent identity.' This fosters immediate solidarity and allows groups to cooperate effectively to solve problems, such as rationing supplies or organizing rescue efforts, by focusing on their common fate.

The button experiment's interpretation hinges on framing. Is pressing Blue an "Ultimate Death Gamble" where you risk your life for the group? Or is pressing Red an "Ultimate Murder Gamble" where you actively risk killing the Blue-pressers? This reframing highlights how moral responsibility is perceived differently based on the narrative.

When platforms like eBay and Craigslist created environments where good or fraudulent behavior was equally possible, studies found a consistent 1000-to-1 ratio of positive to negative transactions. This suggests human nature is fundamentally cooperative, a crucial insight for designing open systems.

People often vote for policies they wouldn't fund voluntarily due to the "moral public good" phenomenon. While an individual might only care slightly about poverty relief, they will support a tax that pools society's resources to create a massive impact, magnifying their small moral preference into a large-scale outcome.

In an experiment, calling a game the "Wall Street Game" led 70% of players to act selfishly. Naming the identical game the "Community Game" caused 70% to share. This shows that situational framing powerfully overrides inherent personality traits like greed or generosity.

A key finding is that almost any outcome better than mutual punishment can be a stable equilibrium (a "folk theorem"). While this enables cooperation, it creates a massive coordination problem: with so many possible "good" outcomes, agents may fail to converge on the same one, leading to suboptimal results.