We report results from two different settings of a 3-player ultimatum game. Under the monocratic rule, a player is randomly selected to make an offer to two receivers. Under the democratic rule, all three players make a proposal, and one proposal is then extracted. A majority vote is required to implement the proposal. Although the two rules are strategically equivalent, different patterns of behaviour seem to emerge as the number of interactions increase. Under the monocratic rule proposers seem to be entitled to claim a larger share of the pie, and receivers more likely to accept, in comparison with the democratic rule. We speculate that ‘institutions’ allowing more participation in the process of collective choice lead to more ‘socially responsible’ behaviour in the players.