Environmental unpredictability and competition in shaping moral reasoning as a manifestation of life history strategies

Moral reasoning can be seen as part of human life history strategies that are responsive to two overarching environmental forces—intraspecific competition and environmental unpredictability. Altruistic and prosocial moral reasoning represents high-K, slow life history strategies that facilitate long-term cooperation and alliance necessary for group living, whereas self-serving moral reasoning represents low-K, fast strategies best suited for short-term gains in unstable living conditions. In two survey studies, we tested and supported the hypotheses that indicators of environmental unpredictability (such as negative life events, financial insecurity, and parental separation) were negatively associated with high-K, slow life history strategy and prosocial moral reasoning (Study 1, n = 303), and that the relationship between competition and prosocial moral reasoning was negative in relatively impoverished rural environment but positive in relatively affluent but competitive urban environment (Study 2, n = 296). In a final experiment (n = 106), imagined unpredictable environment promoted self-serving moral reasoning while imagined competitive environment increased prosocial moral reasoning. These findings provided a life history perspective on moral and social development, suggesting that stable and controllable environment with moderate competition facilitates the co-development of slow life history strategies and prosocial and altruistic morality.