Abstract: Randomizing different schools of thought–via a month-long training– finds that training deputy ministers in effective altruism renders 0.4-0.6 standard deviations increase in altruism. Treated ministers increased mentalizing of others: blood donations doubled, but only when blood banks requested their exact blood type. Perspective-taking in strategic dilemmas improved. Orphanage visits and volunteering in impoverished schools also increased. We then trace the impact of the training on their policymaking: one year after training, amid official duties, ministers were 50-100% more likely to choose social policies and recommend over 4-fold additional funding for them. Overall, our results underscore that effective altruism may be a parsimonious foundation for formation of prosociality, even impacting the behavior of adults in the field and their high-stakes policymaking.