• social trust;
  • generalized interpersonal trust;
  • fairness;
  • homogeneity;
  • heterogeneity;
  • multilevel analysis

This article explores whether homogeneity or fairness better explains generalized interpersonal trust across countries. Although some research suggests that ethnic diversity and income heterogeneity have a negative impact on social trust, I argue that cross-national variations in social trust are better explained by fairness: fair procedural rules (democracy), fair administration of rules (freedom from corruption), and fair income distribution (relatively equal but also unskewed). This expectation is confirmed by a multilevel analysis of data from the World Values Surveys and European Values Study covering 170,000 individuals in 80 countries.