It’s called the Ultimatum Game, and it goes like this: After the students split into pairs of a “proposer” and an “accepter,” I give each proposer $10. The proposer then has to offer the accepter a round number of dollars. If the accepter agrees he or she receives what’s been offered and the proposer gets the rest. If the accepter refuses the offer, though, they both get nothing and the $10 goes back to me.

