Socioeconomic status and vocabulary development among children: a meta-analysis

Vocabulary skills is a key ability for children's cognitive and social development. Although numerous studies demonstrated a positive correlation between SES and children\s vocabulary, the results regarding the extent of, and potential variations in, this relationship remain inconclusive. Therefore, this meta-analysis aimed to explore (a) the overall correlation between SES and children's vocabulary; (b) the moderation effects of age, measurement of SES, and types of vocabulary on this relationship; (c) the relationship between subdimensions of SES (SES index, education, income, and occupation) and subdimensions of vocabulary (receptive vocabulary and expressive vocabulary). 89 studies with 96 independent samples and 244 effect sizes (n = 36589) were included in this meta-analysis. The results showed that there was a moderate correlation between SES and children's vocabulary (r = 0.26, 95%CI [0.22, 0.29]). The measurements of SES, but neither age or types of vocabulary, moderated this relation. The four SES subdimensions were all similarly correlated to two subdimensions of vocabulary. There findings emphasized the significant effect of SES in the children's vocabulary and the necessity of effective intervention to promote the equal development for all children.