title: Assortative mating and differential fertility by phenotype and genotype across the 20th century.
abstract: This study asks two related questions about the shifting landscape of marriage and reproduction in US society over the course of the last century with respect to a range of health and behavioral phenotypes and their associated genetic architecture: (i) Has assortment on measured genetic factors influencing reproductive and social fitness traits changed over the course of the 20th century? (ii) Has the genetic covariance between fitness (as measured by total fertility) and other traits changed over time? The answers to these questions inform our understanding of how the genetic landscape of American society has changed over the past century and have implications for population trends. We show that husbands and wives carry similar loadings for genetic factors related to education and height. However, the magnitude of this similarity is modest and has been fairly consistent over the course of the 20th century. This consistency is particularly notable in the case of education, for which phenotypic similarity among spouses has increased in recent years. Likewise, changing patterns of the number of children ever born by phenotype are not matched by shifts in genotype-fertility relationships over time. Taken together, these trends provide no evidence that social sorting is becoming increasingly genetic in nature or that dysgenic dynamics have accelerated.
authors.affiliation: Department of Sociology, New York University, New York, NY 10003; School of Medicine, New York University, New York, NY 10003; conley@nyu.edu bdomingue@stanford.edu.
authors.forename: Dalton
authors.identifier: 0000-0002-5174-7222
authors.initials: D
authors.lastname: Conley
authors.affiliation: Department of Sociology, New York University, New York, NY 10003;
authors.forename: Thomas
authors.initials: T
authors.lastname: Laidley
authors.affiliation: Duke University School of Medicine, Durham, NC 27708; Social Science Research Institute, Durham, NC 27708;
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Belsky
authors.affiliation: LaFollette School of Public Affairs, University of Wisconsin, Madison, WI 53706;
authors.forename: Jason M
authors.initials: JM
authors.lastname: Fletcher
authors.affiliation: Institute of Behavioral Science, University of Colorado, Boulder, CO 80309;
authors.forename: Jason D
authors.initials: JD
authors.lastname: Boardman
authors.affiliation: Graduate School of Education, Stanford University, Stanford, CA 94305 conley@nyu.edu bdomingue@stanford.edu.
authors.forename: Benjamin W
authors.initials: BW
authors.lastname: Domingue
mesh_terms: D005260:Female; D005298:Fertility / Q000502:physiology*; D055106:Genome-Wide Association Study; D005838:Genotype; D049673:History, 20th Century; D006801:Humans; D008297:Male; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D044465:White People / Q000235:genetics*
keywords: assortative mating; cohort trends; fertility; polygenic scores