Altruism, giving and pro-social conduct, and reciprocity, are the basis of the existence and performance of societies … (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 …

embodying both reciprocity and altruism we show that unconditional altruism towards other members attenuates the punishment … contributions. Increases in altruism may also reduce the level of benefits from the public project net of contribution costs and … punishment costs. The negative effect of altruism on cooperation and material payoffs is greater the stronger is the reciprocity …

that highlights two predictions. First, larger gift amounts, holding education and income constant, is a proxy for altruism …). Second, those motivated by altruism will respond positively to appeals based on evidence, whereas those motivated by warm …