title: Molecular genetic contributions to socioeconomic status and intelligence.
abstract: Education, socioeconomic status, and intelligence are commonly used as predictors of health outcomes, social environment, and mortality. Education and socioeconomic status are typically viewed as environmental variables although both correlate with intelligence, which has a substantial genetic basis. Using data from 6815 unrelated subjects from the Generation Scotland study, we examined the genetic contributions to these variables and their genetic correlations. Subjects underwent genome-wide testing for common single nucleotide polymorphisms (SNPs). DNA-derived heritability estimates and genetic correlations were calculated using the 'Genome-wide Complex Trait Analyses' (GCTA) procedures. 21% of the variation in education, 18% of the variation in socioeconomic status, and 29% of the variation in general cognitive ability was explained by variation in common SNPs (SEs ~ 5%). The SNP-based genetic correlations of education and socioeconomic status with general intelligence were 0.95 (SE 0.13) and 0.26 (0.16), respectively. There are genetic contributions to intelligence and education with near-complete overlap between common additive SNP effects on these traits (genetic correlation ~ 1). Genetic influences on socioeconomic status are also associated with the genetic foundations of intelligence. The results are also compatible with substantial environmental contributions to socioeconomic status.
authors.affiliation: Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, 7 George Square, Edinburgh EH8 9JZ, UK ; Department of Psychology, University of Edinburgh, Edinburgh EH8 9JZ, UK.
authors.forename: Riccardo E
authors.initials: RE
authors.lastname: Marioni
authors.affiliation: Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, 7 George Square, Edinburgh EH8 9JZ, UK ; Department of Psychology, University of Edinburgh, Edinburgh EH8 9JZ, UK ; Medical Genetics Section, Centre for Genomic and Experimental Medicine, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK.
authors.forename: Gail
authors.initials: G
authors.lastname: Davies
authors.affiliation: Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK.
authors.forename: Caroline
authors.initials: C
authors.lastname: Hayward
authors.affiliation: Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, 7 George Square, Edinburgh EH8 9JZ, UK.
authors.forename: Dave
authors.initials: D
authors.lastname: Liewald
authors.affiliation: Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK.
authors.forename: Shona M
authors.initials: SM
authors.lastname: Kerr
authors.affiliation: Medical Genetics Section, Centre for Genomic and Experimental Medicine, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK.
authors.forename: Archie
authors.initials: A
authors.lastname: Campbell
authors.affiliation: Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, 7 George Square, Edinburgh EH8 9JZ, UK ; Department of Psychology, University of Edinburgh, Edinburgh EH8 9JZ, UK.
authors.forename: Michelle
authors.initials: M
authors.lastname: Luciano
authors.affiliation: Medical Research Institute, University of Dundee, Dundee DD2 4RB, UK.
authors.forename: Blair H
authors.initials: BH
authors.lastname: Smith
authors.affiliation: British Heart Foundation Glasgow Cardiovascular Research Centre, Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, UK.
authors.forename: Sandosh
authors.initials: S
authors.lastname: Padmanabhan
authors.affiliation: Musculoskeletal Research Programme, Division of Applied Medicine, University of Aberdeen, Aberdeen AB25 2ZD, UK.
authors.forename: Lynne J
authors.initials: LJ
authors.lastname: Hocking
authors.affiliation: Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK.
authors.forename: Nicholas D
authors.initials: ND
authors.lastname: Hastie
authors.affiliation: Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK.
authors.forename: Alan F
authors.initials: AF
authors.lastname: Wright
authors.affiliation: Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, 7 George Square, Edinburgh EH8 9JZ, UK ; Medical Genetics Section, Centre for Genomic and Experimental Medicine, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK.
authors.forename: David J
authors.initials: DJ
authors.lastname: Porteous
authors.affiliation: Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, 7 George Square, Edinburgh EH8 9JZ, UK ; University of Queensland Diamantina Institute, The University of Queensland, Princess Alexandra Hospital, Brisbane 4072, QLD, Australia ; Queensland Brain Institute, The University of Queensland, Brisbane 4072, QLD, Australia.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Visscher
authors.affiliation: Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, 7 George Square, Edinburgh EH8 9JZ, UK ; Department of Psychology, University of Edinburgh, Edinburgh EH8 9JZ, UK.
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Deary
keywords: Education; Generation Scotland; Genetics; Intelligence; Socioeconomic status