Trajectories of socioeconomic inequality in social, cognitive, and motor development: A birth-cohort

Abstract

Abstract Background The World Health Organization's main strategy to reduce health inequalities in adulthood is preventing socioeconomic inequalities in early childhood. Yet, little is known about how children's socioeconomic position (SEP) shapes their development over time. Therefore, we investigated trajectories of socioeconomic inequality in early child development. Methods Data (n = 5104) was used from Generation R, a prospective population-based cohort in The Netherlands. SEP inequalities (defined by maternal education) in trajectories of internalizing and externalizing problems (mother reported Child Behavior Checklist at 1.5, 3, 5, and 9 years), and of language and motor development (mother reported Child Development Inventory at 0.5, 1, 1.5, 2, 3 and 4 years) were estimated using linear mixed models with standardized scores at each time point. Results Low SEP children had more internalizing (B = 0.72, 95%CI=0.51;0.95) and externalizing (B = 0.25, 95%CI=0.10;0.40) problems at 1.5 years, but better language skills at 1 year (B = 0.50, 95%CI=0.36;0.64), and better fine (B = 0.26, 95%CI=0.12;0.40) and gross motor (B = 0.40, 95%CI=0.25;0.55) skills at 0.5 years of age than high SEP children. For internalizing and externalizing problems, inequalities decreased over time. The low SEP advantage regarding language scores reversed in early childhood, and at 4 years of age, low SEP children (B=-0.38, 95%CI=-0.61;-0.15) had substantially worse language skills than high SEP children. For motor skills, the low SEP advantage at baseline decreased over time and disappeared around 4 years. Conclusions Socioeconomic inequalities in early child development differ by developmental domain: whereas inequalities in problem behavior and motor skills decreased over time, inequalities in language development increased. This indicates that low SEP children are already at a cognitive disadvantage before entering primary education, providing further evidence that interventions are needed before the age of 4. Key messages We investigated trajectories of socioeconomic inequality in early child development within a Dutch prospective birth cohort. Results showed that socioeconomic inequalities in child development decreased over time for emotional, behavioral and motor development, but increased for cognitive development.