Learning Objectives
- To reflect on the principles involved in shaping social behaviour.
- To examine how fairness, public decisions, and the possibility of punishment influence cooperation.
Materials
- Eleven pieces of candy or eleven units of another divisible reward.
- Space for two class representatives to play at the front of the room.
Overview
The class is divided into two groups whose representatives play a public ultimatum game. One player makes a single offer for how to divide a reward. The second player either accepts, allowing both players to receive their share, or rejects, leaving both with nothing.
Procedure
- Split the class into two groups and give each group a few minutes to choose a representative.
- Tell the groups that the representatives will compete for an actual reward. Students may consider whether their representative has agreed to share it with the group.
- Only after both representatives are at the front should you determine who is Player A and Player B. Rock–paper–scissors can be used for this.
- Give Player A eleven pieces of candy. Player A must make one offer to Player B; there is no bargaining.
- If Player B accepts, both receive the proposed shares. If Player B rejects, neither receives anything.
Debrief & discussion questions
- Did you make any deals while deciding who your group representative would be?
- What elements of the game affected your decisions?
- Did playing publicly create more or less incentive to cooperate?
- How were concerns about being worse off than others involved?
- How were concerns about taking more than a fair share involved?
- Why might someone reject an offer even when accepting would leave them with more than nothing?
- How can that rejection be understood in an evolutionary context?
Expected outcomes
In a strictly pragmatic sense, there is no reason to reject a positive offer. However, refusing an unfair offer can function as punishment, potentially encouraging more prosocial behaviour in future interactions.