Timing Uncertainty in Collective Risk Dilemmas Encourages Group Reciprocation and Polarization
Elias Fernández Domingos,
Jelena Grujić,
Juan C. Burguillo,
Georg Kirchsteiger,
Francisco C. Santos,
Tom Lenaerts
Affiliations
Elias Fernández Domingos
AI lab, Computer Science Department, Vrije Universiteit Brussel, Pleinlaan 9, 3rd Floor, 1050 Brussels, Belgium; MLG, Département D’Informatique, Université Libre de Bruxelles, Boulevard Du Triomphe, CP 212, 1050 Brussels, Belgium; Department of Telematic Engineering, University of Vigo, 36310 Vigo, Spain
Jelena Grujić
AI lab, Computer Science Department, Vrije Universiteit Brussel, Pleinlaan 9, 3rd Floor, 1050 Brussels, Belgium; MLG, Département D’Informatique, Université Libre de Bruxelles, Boulevard Du Triomphe, CP 212, 1050 Brussels, Belgium
Juan C. Burguillo
Department of Telematic Engineering, University of Vigo, 36310 Vigo, Spain
Georg Kirchsteiger
ECARES, Université Libre de Bruxelles, Av. Roosevelt 42, CP 114, 1050 Brussels, Belgium
Francisco C. Santos
MLG, Département D’Informatique, Université Libre de Bruxelles, Boulevard Du Triomphe, CP 212, 1050 Brussels, Belgium; INESC-ID and Instituto Superior Técnico, Universidade de Lisboa, IST-Taguspark, 2744-016 Porto Salvo, Portugal; ATP-group, 2744-016 Porto Salvo, Portugal; Corresponding author
Tom Lenaerts
AI lab, Computer Science Department, Vrije Universiteit Brussel, Pleinlaan 9, 3rd Floor, 1050 Brussels, Belgium; MLG, Département D’Informatique, Université Libre de Bruxelles, Boulevard Du Triomphe, CP 212, 1050 Brussels, Belgium; Corresponding author
Summary: Social dilemmas are often shaped by actions involving uncertain returns only achievable in the future, such as climate action or voluntary vaccination. In this context, uncertainty may produce non-trivial effects. Here, we assess experimentally — through a collective risk dilemma — the effect of timing uncertainty, i.e. how uncertainty about when a target needs to be reached affects the participants' behaviors. We show that timing uncertainty prompts not only early generosity but also polarized outcomes, where participants' total contributions are distributed unevenly. Furthermore, analyzing participants' behavior under timing uncertainty reveals an increase in reciprocal strategies. A data-driven game-theoretical model captures the self-organizing dynamics underpinning these behavioral patterns. Timing uncertainty thus casts a shadow on the future that leads participants to respond early, whereas reciprocal strategies appear to be important for group success. Yet, the same uncertainty also leads to inequity and polarization, requiring the inclusion of new incentives handling these societal issues.