Assortative mating on educational attainment leads to genetic spousal resemblance for causal alleles

Article history: Received 7 June 2016 Received in revised form 25 July 2016 Accepted 14 August 2016 Available online xxxx We examinedwhether assortative mating for educational attainment (“likemarries like”) can be detected in the genomes of ~1600 UK spouse pairs of European descent. Assortative mating on heritable traits like educational attainment increases the genetic variance and heritability of the trait in the population,whichmay increase social inequalities. We test for genetic assortative mating in the UK on educational attainment, a phenotype that is indicative of socio-economic status and has shown substantial levels of assortative mating. We use genome-wide allelic effect sizes from a large genome-wide association study on educational attainment (N ~ 300 k) to create polygenic scores that are predictive of educational attainment in our independent sample (r = 0.23, p b 2 × 10). The polygenic scores significantly predict partners' educational outcome (r = 0.14, p = 4 × 10 and r = 0.19, p = 2 × 10, for prediction from males to females and vice versa, respectively), and are themselves significantly correlated between spouses (r= 0.11, p= 7 × 10). Our findings provide molecular genetic evidence for genetic assortative mating on education in the UK. © 2016 Elsevier Inc. All rights reserved.