This paper explores the intergenerational consequences of social exclusion on prosociality. A lab-in-the-field approach in the historical region of Colombia's leper colony reveals that descendants of socially excluded individuals are locally altruistic and extend such altruism to outsiders who have undergone similar circumstances. These individuals also display mistrust toward those who have, historically, been exclusionary—in this case, doctors. The content of historical narratives shared by ancestors who were excluded, which emphasize the endured mistreatment and doctors' historical misinformation, is one mechanism that partially explains the intergenerational patterns.