Social influence in trustors’ neighbourhoods

• We study how the trustors’ behaviour respond to social influence.
• We design an experiment in which three trustors who play with different recipients observe each other over 15 periods.
• We provide clean evidence of contagion and clean evidence of how the individuals’ preference for trust affects the effects of sociality.
• We find that (i) trust is affected by sociality and (ii) the individuals’ preferences for trust enhance the effects of sociality: similar individuals’ preferences induce stronger effects of sociality.

We offer new and clean evidence that social interactions impact on individuals’ choices. In an experimental trust game we study whether and how trustor's behaviour is affected by social influence of other trustors’ choices over time. We account for three important factors of trustors’ preferences: risk attitude, generosity and expected trustworthiness. Our results confirm that trustor's behaviour is affected by peers. We find a general convergence in trusting behaviour: the effect of social influence is (for most of subjects) significantly reducing the amount sent by trustors in each period. Furthermore, analyzing contagion within the neighbourhoods, we find that agents tend to imitate similar types ((un)-generous or (un)trusting) when placed in the same neighbourhood. Indeed – in the few neighbourhoods with a prevalence of generous and risk-loving subjects – trust substantially increases over time. Nearness, without any strategic component, is a clear element of contagion in trustors’ behaviour.