ABSTRACT
Human prosociality is often theorized as an evolved mechanism to support cooperation within small, kin-based groups. Yet contemporary challenges, from climate change to global inequality, require concern for those far beyond our immediate circles. This article explores how evolved intragroup processes, particularly loyalty and identification with one’s group, can be redirected to support far-reaching altruism. We highlight emerging research on exceptionally altruistic individuals, such as living organ donors and effective altruists, who expand their sense of “ingroup” to include distant strangers, future generations, and nonhuman entities. These populations exemplify what philosophers have long described as an expanded moral circle: a progressive broadening of moral concern beyond kinship and locality. Empirical findings reveal that loyalty, a feature of human psychology long thought to promote parochialism, when anchored in inclusive moral identities (e.g., “humanity,” “one’s broader community”), predicts impartial and impactful altruism, even toward targets typically outside the bounds of conventional group-based concern—not just among altruists, but typical adults as well. We argue that such expanded ingroup construals may reflect an evolved prosocial architecture that is more flexible than previously assumed, and that can be leveraged to meet the demands of an increasingly interdependent world.