Averting Depletion in a Two-Player Common Pool Resource Game : Being Seen, the Expectation of Future Encounters, and Biophilia Play a Role in Cooperation

Using a two-player common pool resource game, we investigated the influence of multiple factors on cooperation. Participants (n=116) were informed that the shared resource would be fully replenished in the next round — but only if — both players together consumed less than half of the common pool. Additionally, participants were told the probability (0-100%) of further rounds of play with the same player . To assess the effect of the probability of future rounds, we developed a mathematical model to predict the threshold that would permit a Nash Equilibrium (NE) of Conditional Cooperation (CC). To manipulate visibility, half the pairs were tested in the same room and half in separate rooms. There was a significant effect showing more cooperation in the visible than not visible condition, but no significant effects of NR, CFC, nor postcodes (but NR was significant in interaction with visibility). For predictability of future rounds, we found that there was significantly more CC when the probability of future rounds was ≥69% (congruent with one of our model predictions)