(which they sometimes also create); and in charity and specific organizations. Altruism has various origins: it can be … hedonistic or natural altruism in empathy, affection, sympathy, emotional contagion, pity, and compassion; or normative altruism …Altruism, giving and pro-social conduct, and reciprocity, are the basis of the existence and performance of societies …

laboratory experiment to cleanly fix beliefs about the person's likelihood of being pivotal in reaching a donation threshold that …, with those whose action is pivotal being more than twice as likely to make a donation. We then conduct two field …