Socioeconomic Differences in Cognitive Ability Across Childhood and Adolescence: An Investigation of Genetic, Individual, and Environmental Factors

The level and development of cognitive ability are associated with parental socioeconomic status (SES). Some of these cognitive differences are presumably due to individual differences in genetic predispositions, but the potential mechanisms and influencing factors are still relatively unclear. Previous research has identified factors that show a relation with both cognitive abilities and SES (e.g., parental cognitive ability, home environment, and polygenic scores). Regarding these factors, we analysed three age cohorts (N = 6715; 5, 11, and 17 years old) at a 6-year interval using multiple regressions and decomposition analyses. Firstly, results indicated that cognitive differences linked to SES emerged particularly between the ages of 5 and 11. A substantial part of the SES effect was associated with parental cognitive ability. Secondly, particularly in the oldest cohort, the polygenic score for cognitive ability was related to the SES-associated change in cognitive ability. Finally, in several analyses, the influence of SES on cognitive ability was no longer significant after considering the attendance of the academic track in secondary school. This pattern could indicate that SES-associated differences in secondary school recommendations shown in previous studies may also be associated with SES-related differences in cognitive ability, which should be investigated in future studies.