The idea that people follow trust norms when making trust decisions is developed in an evolutionary model of adaptive play by boundedly rational agents. Because it neither implies nor is it implied by cooperation, trust is not modelled as cooperation in a Prisoners' Dilemma but as a coordination...

We experimentally disentangle two potential sources for endogenous social interactions effects. By comparing groups where the group norm is publicly observable with those where it is not we can measure the size of any endogenous observation effect. By comparing connected with disconnected groups...