Trust in the image of God: Links between religiosity and reciprocity in Haiti

Are religious believers more prosocial than other people? In a trust game field experiment with 774 subjects in Haiti, we elicit willingness to pay to play in the presence of religious images, and argue that this can be interpreted as a measure of the strength of religiosity. More religious individuals trust others more and reciprocate more than others, with effect sizes between 14% and 21% of mean behaviour depending on the measure. They do not reciprocate more in the presence of religious images than without them, nor towards members of the same denomination as themselves. The results support the view that religious affiliation is correlated with intrinsic trustworthiness. We show that lab behaviour correlates with intuitive measures of religiosity outside the lab and with participation in borrowing and lending networks.