Individuals struggle to learn to sustain a common pool resource with conditional cooperators

To sustainably manage our shared resources, we must learn to cooperate with each other and develop more sustainable behaviour over time. However, previous research has found that participants play repeated resource dilemma games less sustainably over time. Improving our understanding of the cause of this is vital to inform policy advocating sustainability. One hypothesis is that increasingly unsustainable behaviour is driven by a few uncooperative actors – if a few act unsustainably then other individuals reciprocate. Alternatively, given the environmental and social uncertainty often found in collective action problems, individuals might struggle to learn to act sustainably even if other uncooperative actors are removed. Here, we experimentally juxtapose these two hypotheses. Over two incentive-compatible experiments involving monetary payments (Experiments 1) and earned tickets to a raffle (Experiment 2), 351 participants played three consecutive resource dilemma games with three computer partners who collectively deployed a conditionally cooperative ('tit-for-tat') strategy (i.e. where one cooperates if others cooperate, but defects if others defect). The best strategy for the participant was to learn to sustain the resource, maximizing the long-term gains of each player. By the third game, only 9.12% of participants were able to use the resource sustainably. We demonstrate that this failure is likely due to difficulty learning the social and environmental dynamics at play. These results suggest that most struggle to learn to act sustainably even when interacting with partners who are willing to cooperate, illuminating a systemic difficulty with learning to act sustainably over time.