Genetic origins of Utilitarian versus Kantian moral philosophy in heritable motivations for egalitarian beneficence and coercive redistribution

Abstract

Utilitarianism is the most influential and controversial philosophical rationale for moral decisions. The recent discovery of two psychological foundations underlying utilitarian versus duty-based moral reasoning allows a test of the genetic basis of these traits. The Oxford Utilitarianism Scale (OUS) assesses Impartial Beneficence – a taste for maximizing well-being with each to count as one, and none for more than one, and Instrumental Harm – a motive to coerce others to redistribute resources. The OUS was administered to a representative sample of Australian twins (n = 439 MZ twins and 627 DZ twins). The overall OUS showed substantial genetic influence (h = 0.52). A well-fitting model dissecting the OUS into impartial beneficence and instrumental harm components revealed that each of these were heritable (h = 0.58, and 0.42 respectively) and largely independent. This suggests that ethical systems run on an emotional dimension from duty-based to utilitarian, in turn reflecting two genetically distinct motivations transmitted down generations.