The Big Three-Mini: Development of a Cross-Culturally Invariant Indicator of Fundamental Character Constructs

Large-scale, cross-cultural research on character requires brief measurement instruments that are psychometrically sound and invariant across cultures. Currently, no measure of character meets all these prerequisites. In this study, we developed the Big Three-Mini, a nine-item instrument designed to assess the three fundamental dimensions of character — heart, mind, and will — based on McGrath's Big Three of Character model. Using data from 27,000 participants across 27 countries, items were selected from the VIA Inventory of Strengths using Ant Colony Optimization to maximize cross-cultural measurement invariance. The resulting Big Three-Mini demonstrated metric invariance across all but one country comparison and scalar invariance across nearly half of them. Exploratory analyses using World Values Survey indicators revealed meaningful associations between the Big Three-Mini dimensions and national well-being. These findings demonstrate that metaheuristic optimization can produce a concise, cross-culturally comparable measure of character, providing a practical tool for international studies on values and flourishing.