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: (1) probability of future rounds, (2) visibility of other participants, (3) biophilia, (4) future discounting, and (5) life history. In each round, participants simultaneously and independently (without conferring) decided how much of the common pool to consume. Participants (n = 116) were informed that the shared resource would be fully replenished in the next round—but only if—both players together consumed ≤ 50% of the common pool in the current round. Additionally, participants were told the probability (0–100%) of further rounds of play with the same player (this probability was not real; it was purely to manipulate the player’s expectations). 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 of Conditional Cooperation (CC). To manipulate visibility, half the pairs were tested in the same room (seen condition) and half in separate rooms (unseen condition). To measure biophilia, the “Nature Relatedness” (NR) scale was used. To measure future discounting, the “consideration of future consequences” (CFC) scale was used. To measure life history, the participant’s UK postcode was obtained (indicating possible residence in a deprived neighbourhood). Participants in our study were not paid. In our results, 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 a number of significant effects using different tests. A notable result was that there was significantly more CC when the probability of future rounds was ≥ 69% (congruent with one of our model predictions).

我们利用一个双人公共资源池博弈，研究了多个因素对合作的影响：（1）未来回合的概率，（2）其他参与者的可见性，（3）亲生命性，（4）未来贴现，以及（5）生活史。在每一回合中，参与者同时且独立地（不进行商议）决定从公共资源池中获取多少资源。参与者（n = 116）被告知共享资源将在下一回合中完全补充——但前提是——在当前回合中两名参与者共同获取的资源不超过公共资源池的50%。此外，参与者被告知与同一参与者进行更多回合博弈的概率（0 - 100%）（此概率并非真实的，纯粹是为了操纵参与者的预期）。为了评估未来回合概率的影响，我们建立了一个数学模型来预测能够允许条件合作（CC）达到纳什均衡的阈值。为了操纵可见性，一半的组合在同一房间内进行测试（可见条件），另一半在不同房间内进行测试（不可见条件）。为了测量亲生命性，使用了“自然关联性”（NR）量表。为了测量未来贴现，使用了“对未来结果的考虑”（CFC）量表。为了测量生活史，获取了参与者的英国邮政编码（这可能表明其居住在贫困社区）。我们研究中的参与者没有报酬。在我们的研究结果中，有一个显著的效应，即与不可见条件相比，在可见条件下合作更多，但NR、CFC以及邮政编码没有显著影响（但NR在与可见性的交互作用中是显著的）。对于未来回合的可预测性，我们通过不同的测试发现了一些显著的效应。一个值得注意的结果是，当未来回合的概率≥69%时，条件合作（CC）显著更多（与我们的一个模型预测相符）。