Research Questions
We will provide new empirical evidence i) on the causal effects of a population-level education policy (1972 Raising of the School Leaving Age ROSLA) that extended compulsory schooling from 15 to 16 on biological ageing in adulthood. ii) on the causal effects of the reform on newly developed measures of cognitive ageing – brain ageing clocks and iii) we will investigate the contribution of biological ageing to the established association between longer schooling and health outcomes, using causal mediation analysis.
Background
Numerous studies attempted to study education and biological ageing but causality was hindered due to limitations around confounding and reverse causation. To overcome this issue, quasi-experimental approaches are employed to study the health effects of educational interventions such as compulsory schooling laws. The evidence on the effects of compulsory schooling laws has shown heterogeneity. Our analysis focuses on the effects of ROSLA on biological ageing. We will take an outcome-wide approach to assess the effects of ROSLA on a range of biological ageing measures including physiological ageing, cognitive ageing, telomere attrition, and proteomic ageing markers. Individuals of the same chronological age often exhibit substantial heterogeneity in their biological profiles and disease susceptibility, indicating the need for better measures of the ageing process. Specifically, measures of biological ageing, using methods such as omics, telomere lengths, or physiological ageing, can capture more accurately the biological profiles of an individual compared their chronological age. Additionally, the progressive development of numerous machine and deep learning models created emerging opportunities for novel conceptualizations of brain ageing biomarkers. Importantly, evidence suggests that the complex processes of ageing create an imperative to examine different types of biological ageing within the same cohort.