Abstract
<p>This paper integrates psychological and philosophical theory and research to explain what it would take to measure a person’s general morality (i.e., their overall moral goodness). Conceptually, to measure general morality, there must be general moral facts about people’s overall morality; the measure must correctly identify and weigh those facts; and the measure must apply clearly and consistently across people, groups, and time. We argue that it would be difficult to operationalize morality in a way that satisfies these requirements. Self-report, informant report, behavioral, and biological measurement approaches also have substantial methodological limitations. These conceptual and methodological challenges limit the validity of measures of general morality more than they do for most other psychological traits. This exercise also yields general lessons about the challenges that also confront the design of narrower, less ambitious morality measures (e.g., of specific moral virtues). Some—but not all—of these challenges can be mitigated when the measurement aims are more modest. It is therefore important to be transparent and intellectually humble about what we can and cannot conclude based on various moral assessments. Finally, we outline recommendations and future directions for psychological and philosophical inquiry into the development and use of morality measures.</p>