S1 Text -

Section A. Genotyping protocol and quality control. Fig A. Predictive accuracy of the polygenic score for years of education predicting child GCSE in TEDS for different P-value thresholds. Fig B. Predictive accuracy of the polygenic score for BMI predicting child BMI in TEDS for different P-value thresholds. Fig C. Predictive accuracy of the polygenic score for binary ADHD predicting ADHD symptoms in TEDS for different P-value thresholds. Table A. Correlations between study variables. Section B. Estimating the effect of X on Y in the single polygenic score case, based on observed associations. Section C. Complete genetic confounding in the single polygenic score case. Section D. Estimating the effect of X on Y in the two polygenic scores case. Annex A. Genetic overlap versus genetic confounding. Annex B. Residual confounding by ancestry, assortative mating and dynastic effects.

(DOCX)