Socioeconomic disparities in neurocognitive development in the first two years of life

Abstract

Socioeconomic status (SES) is strongly associated with cognition and achievement. Socioeconomic disparities in language and memory skills have been reported from elementary school through adolescence. Less is known about the extent to which such disparities emerge in infancy. Here, 179 infants from socioeconomically diverse families were recruited. Using a cohort-sequential design, 90 infants were followed at 9 and 15 months, and 89 were followed at 15 and 21 months. SES disparities in developmental trajectories of language and memory were present such that, at 21 months of age, children of highly educated parents scored approximately .8 standard deviations higher in both language and memory than children of less educated parents. The home language and literacy environment and parental warmth partially accounted for disparities in language, but not memory development.

Keywords: cognitive development; infancy; language; memory; socioeconomic status.

FIGURE 1

Language and Memory Trajectories in the First Two Years Vary by Parent Education. Trajectories of language and memory development were examined longitudinally from 9 to 21 months using mixed effects models. For visualization purposes, Parental Education was considered in three equal tertiles following the distribution of the data: Highest parent education (16 years or higher); Middle parent education (14.5–15.5 years); Lowest parent education (11–14 years). Scores are depicted as Z-scores, to enable comparison across skills. For the Language Composite (top), pairwise comparisons showed significant differences between the slopes of the lowest and middle educated groups (p =.05) and of the lowest and highest educated groups (p =.02). For the Memory Composite (bottom), pairwise comparisons showed significant differences between the slopes of the lowest and middle educated groups (p = .01) and between the lowest and highest educated groups (p = .001).