Backgrounds. For example, using data from the Framingham Heart Study, researchers decomposed total genetic variation into PCs that characterize these otherwise small genetic differences across European subpopulations andDomingue et al.PNAS | June 3, 2014 | vol. 111 | no. 22 |SOCIAL SCIENCESthey calculate a spousal correlation of 0.58 for the first PC in this sample (32). Using similar methods, we estimated a comparable value (r = 0.54) for the first PC among non-Hispanic and white spouses in the HRS. To identify residual GAM, we describe the results from a series of analyses that introduce restrictions in an attempt to understand the extent to which GAM may simply arise from ethnic homogamy within non-Hispanic white couples. These models include the following adjustments: (i) restriction of the sample based on the first PC, (ii) including statistical controls for census division of birth as a proxy for ethnic background, and (iii) estimating GAM with a reduced set of SNPs that do not show any evidence of stratification in our sample.ACKNOWLEDGMENTS. This LarotrectinibMedChemExpress ARRY-470 Research uses data from the HRS, which is sponsored by the National Institute on Aging (Grants NIA U01AG009740, RC2AG036495, and RC4AG039029) and conducted by the University of Michigan. Research was supported by the Eunice Kennedy Shriver National Institute Of Child Health and Human Development (NICHD) of the National get SCIO-469 Institutes of Health (NIH) under Award R21HD078031. The authors also acknowledge cofunding from the NICHD and the Office of Behavioral and Social Sciences Research (1R21HD071884). Further support was provided by the NIH/NICHD-funded CU Population Center (R24HD066613). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.1. Falconer DS, Mackay TFC (1996) Introduction to Quantitative Genetics (Pearson Education Limited, Essex, England), 4th Ed. 2. Neale MC, Cardon LR (1992) Methodology for Genetic Studies of Twins and Families (Kluwer Academic, Dordrecht, The Netherlands). 3. Schwartz CR (2013) Trends and variation in assortative mating: Causes and consequences. Annu Rev Sociol 39:451?70. 4. Blossfeld HP (2009) Educational assortative marriage in comparative perspective. Annu Rev Sociol 35:513?30. 5. Breen R, Salazar L (2011) Educational assortative mating and earnings inequality in the United States. Am J Sociol 117(3):808?43. 6. Thiessen D, Gregg B (1980) Human assortative mating and genetic equilibrium: An evolutionary perspective. Ethol Sociobiol 1:111?40. 7. Blau P (1994) Structural Contexts of Opportunities (Univ of Chicago Press, Chicago). 8. Mare RD (1991) Five decades of educational assortative mating. Am Sociol Rev 56(1): 15?2. 9. Schwartz CR, Mare RD (2005) Trends in educational assortative marriage from 1940 to 2003. Demography 42(4):621?46. 10. Branigan AR, McCallum KJ, Freese J (2013) Variation in the heritability of educational attainment: An international meta-analysis. Soc Forces 92(1):109?40. 11. Rietveld CA, et al.; LifeLines Cohort Study (2013) GWAS of 126,559 individuals identifies genetic variants associated with educational attainment. Science 340(6139): 1467?471. 12. Plomin R, DeFries JC, Roberts MK (1977) Assortative mating by unwed biological parents of adopted children. Science 196(4288):449?50. 13. Center for the Study of Aging (2014) RAND Enhanced Fat Files (RAND Corporation, Santa Monica, CA). Available at www.rand.org/labor/aging/dataprod/enhanced-fa.Backgrounds. For example, using data from the Framingham Heart Study, researchers decomposed total genetic variation into PCs that characterize these otherwise small genetic differences across European subpopulations andDomingue et al.PNAS | June 3, 2014 | vol. 111 | no. 22 |SOCIAL SCIENCESthey calculate a spousal correlation of 0.58 for the first PC in this sample (32). Using similar methods, we estimated a comparable value (r = 0.54) for the first PC among non-Hispanic and white spouses in the HRS. To identify residual GAM, we describe the results from a series of analyses that introduce restrictions in an attempt to understand the extent to which GAM may simply arise from ethnic homogamy within non-Hispanic white couples. These models include the following adjustments: (i) restriction of the sample based on the first PC, (ii) including statistical controls for census division of birth as a proxy for ethnic background, and (iii) estimating GAM with a reduced set of SNPs that do not show any evidence of stratification in our sample.ACKNOWLEDGMENTS. This research uses data from the HRS, which is sponsored by the National Institute on Aging (Grants NIA U01AG009740, RC2AG036495, and RC4AG039029) and conducted by the University of Michigan. Research was supported by the Eunice Kennedy Shriver National Institute Of Child Health and Human Development (NICHD) of the National Institutes of Health (NIH) under Award R21HD078031. The authors also acknowledge cofunding from the NICHD and the Office of Behavioral and Social Sciences Research (1R21HD071884). Further support was provided by the NIH/NICHD-funded CU Population Center (R24HD066613). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.1. Falconer DS, Mackay TFC (1996) Introduction to Quantitative Genetics (Pearson Education Limited, Essex, England), 4th Ed. 2. Neale MC, Cardon LR (1992) Methodology for Genetic Studies of Twins and Families (Kluwer Academic, Dordrecht, The Netherlands). 3. Schwartz CR (2013) Trends and variation in assortative mating: Causes and consequences. Annu Rev Sociol 39:451?70. 4. Blossfeld HP (2009) Educational assortative marriage in comparative perspective. Annu Rev Sociol 35:513?30. 5. Breen R, Salazar L (2011) Educational assortative mating and earnings inequality in the United States. Am J Sociol 117(3):808?43. 6. Thiessen D, Gregg B (1980) Human assortative mating and genetic equilibrium: An evolutionary perspective. Ethol Sociobiol 1:111?40. 7. Blau P (1994) Structural Contexts of Opportunities (Univ of Chicago Press, Chicago). 8. Mare RD (1991) Five decades of educational assortative mating. Am Sociol Rev 56(1): 15?2. 9. Schwartz CR, Mare RD (2005) Trends in educational assortative marriage from 1940 to 2003. Demography 42(4):621?46. 10. Branigan AR, McCallum KJ, Freese J (2013) Variation in the heritability of educational attainment: An international meta-analysis. Soc Forces 92(1):109?40. 11. Rietveld CA, et al.; LifeLines Cohort Study (2013) GWAS of 126,559 individuals identifies genetic variants associated with educational attainment. Science 340(6139): 1467?471. 12. Plomin R, DeFries JC, Roberts MK (1977) Assortative mating by unwed biological parents of adopted children. Science 196(4288):449?50. 13. Center for the Study of Aging (2014) RAND Enhanced Fat Files (RAND Corporation, Santa Monica, CA). Available at www.rand.org/labor/aging/dataprod/enhanced-fa.
