Abstract
In this paper we present results from an experiment that draws on insights from economics on different possible incentives for generosity and insights from social psychology on different possible personality types. Firstly, we test whether the effect of an appeal to a pure altruism motive versus an appeal to a self-interest motive varies across subjects. We find that there is substantial variation, and this variation is strongly correlated with a subject’s level of materialism. Secondly, we test whether spoken appeals and written appeals have different effects. We find no evidence for such a difference. These results have important implications for the fundraising strategies of charities and for experimental design.