Instrumental arguments linking inequality to environmental sustainability often suppose a negative relationship between inequality and social cohesion. While social cohesion is difficult to measure, there are measures of a narrower concept, social trust, and empirical studies have shown that social trust is negatively related to inequality. This paper tests whether at least part of the observed relationship may be explained by income level, rather than income distribution. The study used individual response data from the World Values Survey at the income decile level, finding evidence that income level is indeed important in explaining differences in levels of social trust, but it is insufficient to explain all of the dependence. In the sample used for the study, the authors find that both income level and income distribution help explain differences in social trust between countries.