People often have incomplete information about the consequences of their actions for the payoffs of others. In an experimental allocation game I investigate how the choice to learn about such consequences depends on the costs and benefits of altruistic actions. The results show an asymmetric pattern: while the size of others' potential benefit has little effect, ignorance and selfish behavior go up when information is more `inconvenient', i.e. the fair/efficient alternative is more costly to the decision maker. Thus, in situations of payoff uncertainty, subsidizing fair choices affects prosocial behavior both directly and by increasing the willingness to confront negative consequences of one's actions.