We find that cognitive abilities, educational attainment, and some personality traits indirectly affect ideological preferences through changes in income.
The effects of changes in personality traits on ideology directly and indirectly through income are in the same direction. However, the indirect effects of cognitive abilities and education often offset the direct effects of these variables on ideological preferences. That is, increases in cognitive abilities and education significantly increase income, which reduces the tendency of individuals to express leftist preferences. These indirect effects are in some cases sizeable relative to direct effects. The indirect effects of cognitive abilities through income overwhelm the direct effects such that increasing IQ increases rightwing preferences. For ideological preferences over economic policy the indirect effects of advanced education also overwhelm the direct effects, such that individuals with higher education are more likely to express rightwing preferences
than those with lower education.