Rich communication, social motivations, and coordinated resistance against divide-and-conquer: A laboratory investigation

• This experiment studies how communication coordinates resistance against transgressions.
• Agents who face asymmetric economic and social incentives communicate differently.
• Moving from restrictive to free-form communication quadruples the joint resistance rate.
• Multiple opportunities to indicate intentions alone are not powerful in increasing resistance.

This paper presents a laboratory experiment to investigate how social motivations and free-form communication (Rich Communication) can facilitate coordinated resistance against divide-and-conquer transgressions. In our experiment, a leader first decides whether to extract surplus from a victim and shares it with a beneficiary. We find that the successful joint resistance rate increases almost four-fold (from 15 to 58%) when moving from more restrictive communication treatments to Rich Communication. We also find that the significant impacts of Rich Communication are driven more by the responders' ability to send free-form messages rather than the multiple and iterative opportunities to indicate intentions.