Mediation of the gravitational influence of intelligence on socio-economic outcomes

The 'gravitational hypothesis' posits that the strength of the association between intelligence and occupational position should increase with age. Here, it is tested in an age-homogeneous, population-representative sample of Swedish men (N = 49,246). Intelligence had a positive effect on occupational and income trajectories, supporting the hypothesis. Although weaker, socio-economic background also had a positive effect on occupational and income trajectories. Both the effect of intelligence and of socioeconomic background was to a large extent mediated by subjects' education level. Intelligence, socio-economic background, and level of education were also found to have a positive association with a deceleration of the increase in occupational position and income with age.