Unequal educational outcomes for children with similar early childhood vocabulary but different socio-economic circumstances

In a purely meritocratic society educational outcomes would reflect ability, and only ability. Vocabulary size is a common measure of cognitive ability that predicts educational outcomes but is confounded with socioeconomic circumstances (SEC). Methods. In preregistered analyses of the nationally representative UK Millennium Cohort Study data (N=15,576), we used a series of multiple linear and logistic regression analyses to investigate the predictive value of age-5 vocabulary for age-16 educational outcomes and assess whether socioeconomic circumstance moderated this relation. Results. We show that age-5 vocabulary strongly predicted age-16 educational attainment, even after adjusting for both SEC and caregiver vocabulary (OR = 1.62, 95% CIs = [1.52;1.72]; ( = .22, 95% CIs = [.19;.24]). However, the weight of evidence for the effect was lower than that for the effect of SEC (i.e., SEC was found to have better predictive value. Further, a larger vocabulary was most advantageous for those in middle SEC groups (interaction term OR 1.09 [1.03; 1.15). Conclusions. This demonstrates that even children who enter school with relatively strong language skills are not that likely to gain gateway qualifications if they experience socio-economic disadvantage. Early language interventions may help children to access education but cannot by themselves be expected to counteract the effect of social inequality on life chances.