Distributional justice—measured by the proportionality between effort exerted and rewards obtained—and guilt aversion—triggered by not fulfilling others’ expectations—are widely acknowledged fundamental sources of pro-social behavior. We design three experiments to study the relevance of these sources of behavior when considered in interaction. In particular, we investigate whether subjects fulfill others’ expectations also when this could produce inequitable allocations that conflict with distributional justice considerations. Our results confirm that both justice considerations and guilt aversion are important drivers of pro-social behavior, with (...) the former having an overall stronger impact than the latter. Expectations of others are less relevant in environments more likely to nurture equitable outcomes. (shrink)