From another article about this research [1], here's what they controlled for in terms of other potential correlations: "This effect persisted after controllin

From another article about this research [1], here's what they controlled for in terms of other potential correlations: "This effect persisted after controlling for parent's social/economic status, qualifications and employment." [1] https://www.eurekalert.org/pub_releases/2017-06/kcl-odh061917.php https://www.eurekalert.org/pub_releases/2017-06/kcl-odh06191... Haven't read the original paper yet, so no opinion on quality of the reported research.