There is no evidence of accumulating socioeconomic advantage. Ability explains the SES effect that increases with age on children's domain test scores

https://doi.org/10.1016/j.intell.2021.101582

Explanation

Previous studies investigating the effect of socioeconomic background (SES) on performance have found many inconsistencies between studies, explaining the tendency to find stronger SES effects with age.

Some academic literature has argued that SES inequalities increase as children get older, a type of what is called the Mathew effect.

In this study, we analyze data from children of NLSY79 mothers (N≈9000, Obs≈27,000) to investigate the relationship between child age and SES for two cognitive domains and three achievement domains.

We find a slight increase in SES-test score correlations, but an even more substantial increase in test score correlations with maternal ability and previous ability. Regression analysis showed that the SES effect increased linearly in all domains except for numeracy memory. However, we also found that the greatly reduced SES　effect did not increase with the age of the child when maternal ability was taken into account.

The effect of SES on children's domain scores is explained by maternal ability, and the effect of previous ability also increases with age, but the effect of SES is small.

There is no evidence of cumulative socioeconomic benefits for these domains, and the results suggest that the increased impact of SES on children's cognitive development and student performance may be spurious because of the importance of general parental competence and its transmission to children.