Mapping Morality with a Compass: Testing the theory of ‘morality as cooperation’ with a new questionnaire

Morality-as-Cooperation (MAC) is the theory that morality is a collection of biological and cultural solutions to the problems of cooperation recurrent in human social life. MAC uses game theory to identify distinct types of cooperation, and predicts that each will be considered morally relevant, and each will give rise to a distinct moral domain. Here we test MAC's predictions by developing a new self-report measure of morality, the Morality-as-Cooperation Questionnaire (MAC-Q), and comparing its psychometric properties to those of the Moral Foundations Questionnaire (MFQ). Over four studies, the results support MAC's seven-factor model of morality, but not the MFQ's five-factor model. Thus MAC emerges as the best available compass with which to explore the moral landscape.