Parental Education-related Gaps in Externalising Behaviour at age 3–4 Years: Evidence from a Harmonised Framework from the United Kingdom, the United States, and the Netherlands

Background: Research on factors underlying socioeconomic status (SES)-related inequalities in child development mainly focuses on single countries and specific influential factors. Only few studies scrutinize to what extent differences in children’s early behavioural outcomes vary across countries and whether the processes that account for them are common or context-specific. Objective: The aim of this study was to explore SES-related inequalities and explanatory factors in 3- to 4-year-old children’s externalising behaviour as well as their generalisability across outcome variables (hyperactivity, conduct problems) and countries. Methods: The study uses harmonised data from three longitudinal large-scale studies conducted in the United Kingdom (UK), the United States (US), and the Netherlands and a decomposition method to comparatively analyse early SES-related gaps and explanatory factors. Results: Results show that the extent of parental education-related gaps varied across countries. The included explanatory factors accounted for significant amounts of gaps in hyperactivity and conduct problems. Yet, while family income and maternal depressive feelings significantly explained gaps in each facet of externalising behaviour across all three countries, other factors were country-specific. In the US and the UK, health-related factors were additionally relevant for explaining early gaps in both child outcomes; in the UK, also structural aspects of the family significantly explained gaps in conduct problems; no other factors contributed to the explanation of gaps in the Netherlands. Conclusions: Mechanisms that might reduce SES-related inequalities in child behaviour and that may be helpful when constructing appropriate interventions are partially similar, yet also significantly different between countries and child outcomes.