We conducted GWAS of educational attainment, an outcome with a high genetic correlation with intelligence5, in a non-overlapping European subset of the UKB sample (N=188,435) who did not complete the intelligence measure. Educational attainment was coded as maximum years of education completed, using the same methods as earlier analyses40 and GWAS was conducted using the same quality control and analytic procedures as described for the UKB intelligence phenotype (Supplementary Information 1.1.1). To test replication of the SNPs with this proxy phenotype, we performed a sign concordance test for all GWS SNPs from the meta-analysis using the two-tailed exact binomial test. For each independent genomic locus, we considered it to be evidence for replication if the lead SNP or another correlated SNP in the region was sign concordant with the corresponding SNP in the intelligence meta-analysis and had a two-tailed P-value of association with educational attainment smaller than 0.05/242 independent tests=0.0002.
