Table S3.

Strategies and understanding about the game were correlated

Type (vs. computers)Answer: no*Answer: yesAnswer: sometimesAnswer: unsureTotal
Unconditional cooperators21205
Conditional cooperators6187536
Negative cooperators11103
Humped cooperators03104
  • Response to question asking if players understood that the income maximizing strategy does not depend on what others contribute. Question asked: “In the game, if a player wants to maximize his or her earnings in any one particular round, does the amount they should contribute depend on what the other people in their group contribute?”

  • * This is the correct answer.