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Couple formation and assortative mating significantly influence societal structures, as marriages between individuals from diverse geographical or social backgrounds promote intra-family diversity. Understanding these patterns is crucial for grasping the demographic processes that shape contemporary societies. However, the scarcity of comprehensive data has impeded progress in this area. This paper aims to fill this gap by investigating assortative mating trends in the United States among birth cohorts from 1700 to 1910, utilizing data from FamiLinx, an online crowdsourced genealogical database. We focus on two primary dimensions: migration background (including natives, first and second-generation migrants) and age at marriage. Our analysis yields three major findings. First, we document significant changes in assortative mating trends over time, reflecting the dynamic nature of mate selection and its responsiveness to societal shifts. Second, we uncover substantial heterogeneity in assortative mating patterns across different social groups, indicating varying social dynamics and preferences. Third, we illustrate how these trends can be differently interpreted depending on whether the perspective is individual or familial. Additionally, we explore the advantages and limitations of using online genealogical data for historical studies of assortative mating, highlighting its potential for offering new insights while acknowledging the challenges posed by data quality and representativeness. [ABSTRACT FROM AUTHOR]

Recent social and economic trends in the United States, including increasing economic inequality, women's growing educational advantage, and the rise of online dating, have ambiguous implications for patterns of educational homogamy. In this research note, we examine changes in educational assortative mating in the United States over the last eight decades (1940 to 2020) using the U.S. decennial censuses and the American Community Survey, extending and expanding earlier work by Schwartz and Mare. We find that the rise in educational homogamy noted by Schwartz and Mare has not continued. Increases in educational homogamy stalled around 1990 and began reversing in the 2000s. We find a growing tendency for marriages to cross educational boundaries, but a college degree remains the strongest dividing line to intermarriage. A key trend explaining this new pattern is women's increasing tendency to marry men with less education than themselves. If not for this trend, homogamy would have continued increasing until the early 2010s. We also show substantial heterogeneity by race, ethnicity, and nativity and among same- versus different-sex couples. [ABSTRACT FROM AUTHOR]

Few studies have followed immigrant-origin individuals from adolescence to adulthood or examined their spousal choices. Using longitudinal data from Add Health, we present a life-course model that examines the differences in racial assortative mating between children of immigrants and non-immigrants. The results reveal substantial variation in racial endogamy from generation to generation. Racial endogamy was highest in the third generation, but this is due entirely to high racial endogamy among whites. Out-marriage was most pronounced among first- and second-generation immigrants. Our life-course approach shows that the effects of race and generation on intermarriage were mediated by family background (e.g. language proficiency and residence) and educational attainment (at time of marriage), a finding largely indicative of processes of marital assimilation that unfold over time and generation. Evidence of acculturation and structural assimilation, however, could not fully account for the large, persistent, and uneven effects of race and generation on interracial marriage. [ABSTRACT FROM AUTHOR]

We use census microdata for Spain and the United States to examine gender differences in cross‐national heterosexual couples (marriages and cohabitating unions involving natives and immigrant spouses). We examine whether native men and native women in cross‐national couples exhibit similar patterns regarding the country of birth, age, and educational attainment of their international partners. Countries are ranked by their level of the human development index (HDI). In both Spain and the United States, native men are slightly overrepresented in cross‐national couples. Native men are more likely to be married to individuals from low HDI countries than native women. On the contrary, native women are predominantly married to men born in countries with similar or higher levels of HDI. Unions of native men are characterized by large spousal age differences, which increase with the HDI gap; this pattern reverses among native women. These gender asymmetries do not extend to education level, with cross‐national couples, overall, involving highly educated individuals. These results point to the endurance of certain features of traditional marriage patterns in cross‐national couples, but the patterns differ starkly between native men and native women. [ABSTRACT FROM AUTHOR]

Intermarriage among ethnic groups belonging to the same panethnic category (e.g., Asian, Latino) is an important indicator of the strength of panethnicity. Yet, most of the research on panethnic intermarriage uses older samples with signif­icant data limitations. In this article, I use data on recently married couples from the 2014–2018 American Community Surveys and the 1980 U.S. Census to analyze the likelihood of ethnic exogamy within the panethnic categories of Latino, East/Southeast Asian, and South Asian. I utilize a counterfactual marriage model that accounts for group size within local marriage markets, eliminates immigrants married abroad from analysis, and controls for birthplace and language endogamy. The results show that birthplace and language diversity are signif­icant barriers to ethnic exogamy among Asians but not Latinos. Once birthplace and language endogamy are held constant, panethnic intermarriage is far more likely among Asians than among Latinos. East/Southeast Asian ethnic exogamy has increased over time, while Latino ethnic exogamy has not. Furthermore, East/Southeast Asian and South Asian intermarriage remains rare, suggesting that panethnic intermarriage among Asians occurs within two separate melting pots. [ABSTRACT FROM AUTHOR]

The objective of this study was to clarify how bias in genomic predictions is created by investigating a relationship among selection intensity, a change in heritability (Δ h 2), and assortative mating (ASM). A change in heritability, resulting from selection, reflects the impact that the Bulmer effect has on the reduction in between-family variation, whereas assortative mating impacts the within-family variance or Mendelian sampling variation. A partial data set up to 2014, including 841K genotyped animals, was used to calculate genomic predictions with a single-step genomic model for 18 linear type traits in US Holsteins. A full data set up to 2018, including 2.3 million genotyped animals, was used to calculate benchmark genomic predictions. Inbreeding and unknown parent groups for missing parents of animals were included in the model. Genomic evaluation was performed using 2 different genetic parameters: those estimated 14 yr ago, which have been used in the national genetic evaluation for linear type traits in the United States, and those newly estimated with recent records from 2015 to 2018 and those corresponding pedigrees. Genetic trends for 18 type traits were estimated for bulls with daughters and cows with phenotypes in 2018. Based on selection intensity and mating decisions, these traits can be categorized into 3 groups: (a) high directional selection, (b) moderate selection, and (c) intermediate optimum selection. The first 2 categories can be explained by positive assortative mating, and the last can be explained by negative assortative or disassortative mating. Genetic progress was defined by genetic gain per year based on average standardized genomic predictions for cows from 2000 to 2014. Traits with more genetic progress tended to have more "inflated" genomic predictions (i.e., "inflation" means here that genomic predictions are larger in absolute values than expected, whereas "deflation" means smaller than expected). Heritability estimates for 14 out of 18 traits declined in the last 16 yr, and Δ h 2 ranged from −0.09 to 0.04. Traits with a greater decline in heritability tended to have more deflated genomic predictions. Biases (inflation or deflation) in genomic predictions were not improved by using the latest genetic parameters, implying that bias in genomic predictions due to preselection was not substantial for a large-scale genomic evaluation. Moreover, the strong selection intensity was not fully responsible for bias in genomic predictions. The directional selection can decrease heritability; however, positive assortative mating, which was strongly associated with large genetic gains, could minimize the decline in heritability for a trait under strong selection and could affect bias in genomic predictions. [ABSTRACT FROM AUTHOR]

BACKGROUND Research on assortative mating - how partner characteristics affect the likelihood of union formation - commonly uses the log-linear model, but this approach has been criticized for its complexity and limitations. OBJECTIVE The objective of this paper is to fully develop and illustrate a counterfactual model of assortative mating and to show how this model can be used to address specific limitations of the log-linear model. METHODS The model uses a sample of alternate counterfactual unions to estimate the odds of a true union using a conditional logit model. Recent data from the United States are used to illustrate the model. RESULTS Results show important biases can result from assumptions about the marriage market implicit in existing methods. Assuming that spouses are drawn from a national-level marriage market leads to underestimates of racial exogamy and educational heterogamy, while the exclusion of the unmarried population (the unmarried exclusion bias) leads to overestimates of these same parameters. The results also demonstrate that controls for birthplace and language endogamy substantially affect our understanding of racial exogamy in the United States, particularly for Asian and Latino populations. CONCLUSIONS The method gives the researcher greater control of the specification of the marriage market and greater flexibility in model specification than the more standard log-linear model. [ABSTRACT FROM AUTHOR]

Social norms regarding who marries whom have changed dramatically in the United States across the 20th century. These changes may influence the level of genetic similarity between spouses. This study investigates whether genetic similarity in height between husband and wife was influenced by a historical transition in spouse selection criteria. The great transition from the companionate marriage to the individualized marriage occurred in the 1960s. In the companionate marriage, husband and wife chose each other as companions, and the emphasis was on playing marital roles well: husbands being good breadwinners and wives being good homemakers. In the individualized marriage, the emphasis switched to individual feelings, and as a result, when choosing their partners people tended to pay less attention to height, suggesting a smaller genetic correlation for height between spouses. Using data from the Health and Retirement Study, we found that the genetic correlation for height declined substantially in the individualized marriage. We conducted a number of analyses to test for the confounding effects of cohort and age and to address population stratification, selection issues, and genetic relatedness between spouses. Evidence suggests that the effect of this transition is robust. [ABSTRACT FROM AUTHOR]

Households make economic tradeoffs over time. We seek to understand how a spouse's individual time preference influences joint household decisions. We conduct a field experiment with 94 pairs of couples in the United States. Each subject makes a series of choices between payoffs received at two different times for oneself and then jointly with their spouse as a household. Results from our sample indicate that husbands do not have more influence than their wives do on the joint decision. This finding differs from previous conclusions drawn from data collected in developing countries. We further find that differences in education, age, and earned income do not provide spouses with additional bargaining power. However, the relative power shifts based on individual preferences related to patience, savings, risk tolerance, and which spouse controls the household income. Lastly, our data supports assortative mating based on time preferences, but we do not find evidence supportive of spousal socialization, spousal selection, or changing matching patterns on time preferences. [ABSTRACT FROM AUTHOR]

This research has two goals: to measure the extent of assortative (non-random) mating by college major in the United States, and to assess the extent to which assortative mating by college major increases earnings inequality among college-educated couples. Assortative mating of college graduates with other college graduates has been extensively studied, but research on assortative mating by field of study is rare. The analysis uses a large sample (659,732 couples) from five years of the American Community Survey public use files to group college degrees into nine categories, compute the frequency of all marital pairings, and compare these frequencies to a random assignment of pairings. The results show that assortative mating by college major is common for all majors and both genders, and that these results are robust to division of the sample by age group. Because high-earning majors tend to be married to spouses from the same high-earning major group, and likewise for low-earning majors, assortative mating increases earnings inequality among two-earner college-educated couples. The extent of this increased earnings inequality is calculated with both dollar measures and standard aggregate measures of inequality. Thus college-educated Americans tend to marry persons with similar college majors and this tendency measurably increases earnings inequality among college-educated couples. [ABSTRACT FROM AUTHOR]

Educational assortative mating patterns in the United States have changed since the 1960s, but we know little about the effects of these patterns on children, particularly on infant health. Rising educational homogamy may alter prenatal contexts through parental stress and resources, with implications for inequality. Using 1969–1994 NVSS birth data and aggregate cohort-state census measures of spousal similarity of education and labor force participation as instrumental variables (IV), this study estimates the effects of parental educational similarity on infant health. Controlling for both maternal and paternal education, results support family systems theory and suggest that parental educational homogamy is beneficial for infant health while hypergamy is detrimental. These effects are stronger in later cohorts and are generally limited to mothers with more education. Hypogamy estimates are stable by cohort, suggesting that rising female hypogamy may have limited effect on infant health. In contrast, rising educational homogamy could have increasing implications for infant health. Effects of parental homogamy on infant health could help explain racial inequality of infant health and may offer a potential mechanism through which inequality is transmitted between generations. [ABSTRACT FROM AUTHOR]

The effect of assortative mating on offspring is often not considered. Here, we present data on illness in the spouse and the parents of patients with bipolar disorder as they affect illness in the offspring. A history of psychiatric illness (depression, bipolar disorder, suicide attempt, alcohol abuse, drug abuse, and "other" illness) was elicited for the parents, spouse, and the offspring of 968 patients with bipolar disorder (540 of whom had children) who gave informed consent for participation in a treatment outcome network. Assortative mating for a mood disorder in the spouse and parents in those from the United States (US) was compared to those from the Netherlands and Germany and related to illnesses in the offspring. There was more illness and assortative mating for a mood disorder in both the spouse and patient's parents from the US compared to Europe. In the parents of the US patients, assortative mating for a mood disorder was associated with more depression, bipolar disorder, alcohol, and "other" illness in the offspring. Compared to the Europeans, there was more assortative mating for mood and other disorders in two generations of those from the US. This bilineal positivity for a parental mood disorder was related to more depression a second generation later in the patients' offspring. In clinical assessment of risk of illness in the offspring, the history of psychiatric illness in the spouse and patient's parents might provide additional information. [ABSTRACT FROM AUTHOR]

In this paper, we describe mating patterns in the USA from 1964 to 2017 and measure the impact of changes in marital preferences on between-household income inequality. We rely on the recent literature on the econometrics of matching models to estimate complementarity parameters of the household production function. Our structural approach allows us to measure sorting along multiple dimensions and to effectively disentangle changes in marital preferences and in demographics, addressing concerns that affect results from existing literature. We answer the following questions: Has assortativeness increased over time? Along which dimensions? To what extent can the shifts in marital preferences explain inequality trends? We find that, after controlling for other observables, assortative mating in education has become stronger. Moreover, if mating patterns had not changed since 1971, the 2017 Gini coefficient between married households would be 6% lower. We conclude that about 25% of the increase in between-household inequality is due to changes in marital preferences. Increased assortativeness in education positively contributes to the rise in inequality, but only modestly. [ABSTRACT FROM AUTHOR]

Research on neighborhood effects draws suggestive links between local spatial environments and a range of social, economic, and public health outcomes. Here, we consider the potential role of genetics in the geography of social stratification in the United States using genomic data from the National Longitudinal Study of Adolescent to Adult Health. We find that those with genotypes related to higher educational attainment sort into neighborhoods that are better educated and have higher population densities, both descriptively and using formal school and sibling fixed-effects models. We identify four mechanisms through which this geographic sorting on genetic endowment can magnify social stratification: assortative mating, social-genetic effects, gene-by-environment interactions, and gene-by-social-genetic interactions. We examine the presence of the latter three in our data, finding provisional yet suggestive evidence for social-genetic effects that putatively amount to about one-third of the influence of one's own genomic profile. We find no evidence, however, for the presence of interactions between environments and individual genetic background. Collectively, these findings highlight the potential for geographic sorting on genotype to emerge both as a key methodological concern in population genetics and social science research and also a potentially overlooked dimension of social stratification worthy of future study. [ABSTRACT FROM AUTHOR]

This study examines proximate sources of change in first-marriage trajectories in the United States between 1960 and 2010. This was a period of tremendous social change: divorce became more common, people started marrying later or not marrying at all, innovations in medicine and changes in social and behavioral factors led to reduced mortality, inequality grew stronger and was reflected by more intense assortative mating, and the country underwent a massive educational expansion. Each of these factors influenced the formation and dissolution of first marriages over this period. This article extends the multiple-decrement life table to incorporate heterogeneity and assortative mating, which allows the quantification of how changes in the incidence of marriage, divorce, and mortality, along with changes in educational attainment and assortative mating, have shaped trends in first-marriage trajectories. The model is used to prove that stronger educational assortative mating leads to longer average durations of first marriage. Using data from multiple sources and this model, this study shows that although the incidence of divorce was the primary determinant of changes in first-marriage trajectories between 1960 and 1980, it has played a relatively smaller role in driving change in marital trajectories between 1980 and 2010. Instead, factors such as later age at first marriage, educational expansion, declining mortality, narrowing sex differences in mortality, and more intense educational assortative mating have been the major drivers of changes in first-marriage trajectories since 1980. [ABSTRACT FROM AUTHOR]

As more Americans delay marriage and meet partners online, schools may be less important for educational assortative mating. At the same time, social ties formed during college may continue to shape partner choice later in adulthood. This study focuses on young adults with “some college, no degree” to see what, if any, marriage‐market benefit is gained from exposure to highly educated social networks in college. Using data from the National Longitudinal Study of Youth 1997, including newly collected postsecondary transcripts, the author finds young adults with “some college” are more likely than their less‐educated peers to marry a college graduate, especially if they attended a 4‐year school, but young adults with bachelor's degrees still hold an advantage, even after controlling for duration of schooling. The results support the role of schools in shaping opportunities to meet partners but highlight the value of college degrees on the marriage market. [ABSTRACT FROM AUTHOR]

Background: Considerable evidence from twin and adoption studies indicates that genetic and shared environmental factors play a role in the initiation of smoking behavior. Although twin and adoption designs are powerful to detect genetic and environmental influences, they do not provide information on the processes of assortative mating and parent-offspring transmission and their contribution to the variability explained by genetic and/or environmental factors.Methods: We examined the role of genetic and environmental factors in individual differences for smoking initiation (SI) using an extended kinship design. This design allows the simultaneous testing of additive and non-additive genetic, shared and individual-specific environmental factors, as well as sex differences in the expression of genes and environment in the presence of assortative mating and combined genetic and cultural transmission, while also estimating the regression of the prevalence of SI on age. A dichotomous lifetime 'ever' smoking measure was obtained from twins and relatives in the 'Virginia 30,000' sample and the 'Australian 25,000'.Results: Results demonstrate that both genetic and environmental factors play a significant role in the liability to SI. Major influences on individual differences appeared to be additive genetic and unique environmental effects, with smaller contributions from assortative mating, shared sibling environment, twin environment, cultural transmission, and resulting genotype-environment covariance. Age regression of the prevalence of SI was significant. The finding of negative cultural transmission without dominance led us to investigate more closely two possible mechanisms for the lower parent-offspring correlations compared to the sibling and DZ twin correlations in subsets of the data: (1) age × gene interaction, and (2) social homogamy. Neither of the mechanism provided a significantly better explanation of the data.Conclusions: This study showed significant heritability, partly due to assortment, and significant effects of primarily non-parental shared environment on liability to SI. [ABSTRACT FROM AUTHOR]

Drawing on data from the American Community Survey, we compare patterns of assortative mating in first marriages, remarriages, and mixed-order marriages. We identify a number of ascribed and achieved characteristics that are viewed as resources available for exchange, both as complements and substitutes. We apply conditional logit models to show how patterns of assortative mating among never-married and previously married persons are subject to local marriage market opportunities and constraints. The results reveal that previously married individuals "cast a wider net": spousal pairings are more heterogamous among remarriages than among first marriages. Marital heterogamy, however, is reflected in systematic evidence of trade-offs showing that marriage order (i.e., status of being never-married) is a valued trait for exchange. Never-married persons are better positioned than previously married persons to marry more attractive marital partners, variously measured (e.g., highly educated partners). Previously married persons-especially women-are disadvantaged in the marriage market, facing demographic shortages of potential partners to marry. Marriage market constraints take demographic expression in low remarriage rates and in heterogamous patterns of mate selection in which previously married partners often substitute other valued characteristics in marriage with never-married persons. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: African American populations in the U.S. formed primarily by mating between Africans and Europeans over the last 500 years. To date, studies of admixture have focused on either a one‐time admixture event or continuous input into the African American population from Europeans only. Our goal is to gain a better understanding of the admixture process by examining models that take into account (a) assortative mating by ancestry in the African American population, (b) continuous input from both Europeans and Africans, and (c) historically informed variation in the rate of African migration over time. Materials and methods: We used a model‐based clustering method to generate distributions of African ancestry in three samples comprised of 147 African Americans from two published sources. We used a log‐likelihood method to examine the fit of four models to these distributions and used a log‐likelihood ratio test to compare the relative fit of each model. Results: The mean ancestry estimates for our datasets of 77% African/23% European to 83% African/17% European ancestry are consistent with previous studies. We find admixture models that incorporate continuous gene flow from Europeans fit significantly better than one‐time event models, and that a model involving continuous gene flow from Africans and Europeans fits better than one with continuous gene flow from Europeans only for two samples. Importantly, models that involve continuous input from Africans necessitate a higher level of gene flow from Europeans than previously reported. Discussion: We demonstrate that models that take into account information about the rate of African migration over the past 500 years fit observed patterns of African ancestry better than alternative models. Our approach will enrich our understanding of the admixture process in extant and past populations. [ABSTRACT FROM AUTHOR]

This study investigates gender-specific changes in the total financial return to education among persons of prime working ages (35-44 years) using U.S. Census data from 1990 and 2000, and the 2009-2011 American Community Survey. We define the total financial return to education as the family standard of living as measured by family income adjusted for family size. Our results indicate that women experienced significant progress in educational attainment and labor market outcomes over this time period. Ironically, married women's progress in education and personal earnings has led to greater improvement in the family standard of living for married men than for women themselves. Gender-specific changes in assortative mating are mostly responsible for this paradoxical trend. Because the number of highly educated women exceeds the number of highly educated men in the marriage market, the likelihood of educational marrying up has substantially increased for men over time while women's likelihood has decreased. Sensitivity analyses show that the greater improvement in the family standard of living for men than for women is not limited to prime working-age persons but is also evident in the general population. Consequently, women's return to education through marriage declined while men's financial gain through marriage increased considerably. [ABSTRACT FROM AUTHOR]

Recent evidence from the United States suggests that the reversal of the gender gap in education was associated with changes in relative divorce risks: hypogamous marriages, where the wife was more educated than the husband, used to have a higher divorce risk than hypergamous marriages, where the husband was more educated, but this difference has disappeared. One interpretation holds that this may result from cultural change, involving increasing social acceptance of hypogamy. We propose an alternative mechanism that need not presuppose cultural change: the gender-gap reversal in education has changed the availability of alternatives from which highly educated women and men can choose new partners. This may have lowered the likelihood of women leaving husbands with less education and encouraged men to leave less educated spouses. We applied an agent-based model to twelve European national marriage markets to illustrate that this could be sufficient to create a convergence in divorce risks. [ABSTRACT FROM PUBLISHER]

Evidence of a high or increasing incidence of childhood onset bipolar disorder in the United States (US) has been viewed skeptically. Here we review evidence that childhood onsets of bipolar disorder are more common in the US than in Europe, treatment delays are longer, and illness course is more adverse and difficult. Epidemiological data and studies of offspring at high risk also support these findings. In our cohort of outpatients with bipolar disorder, two of the major vulnerability factors for early onset − genetics and environmental adversity in childhood − were also greater in the US than in Europe. An increased familial loading for multiple psychiatric disorders was apparent in 4 generations of the family members of the patients from the US, and that familial burden was linked to early onset bipolar disorder. Since both early onset and treatment delay are risk factors for a poor outcome in adulthood, new clinical, research, and public health initiatives are needed to begin to address and ameliorate this ongoing and potentially devastating clinical situation. [ABSTRACT FROM AUTHOR]

As interfaith marriage has become more common, religion is thought to be less important for sorting partners. Nevertheless, prior studies on religious assortative mating use samples of prevailing marriages, which miss how local marriage markets shape both partner selection and marriage timing. Drawing on search theory and data from 8,699 young adults (ages 18-31 years) in the National Longitudinal Study of Youth 1997, the author examined the association between the concentration of coreligionists in local marriage markets and marriage timing and partner selection using event history methods. Religious concentration is associated with higher odds of transitioning to marriage and religious homogamy (conditional on marriage) for women and men at older ages (24-31 years) but not at younger ages (18-23 years). The association was also stronger for non-Hispanic Whites when compared with other racial and ethnic groups. The findings indicate that religion remains relevant in sorting partners for many young adults in today's marriage market. [ABSTRACT FROM AUTHOR]

Prior studies have found a robust correlation in the education of dating and married couples. However, there is little evidence to suggest that such correlations are causal, that is, for the sake of relationship public goods such as the pleasures of the enlightened conversations that only a common high level of education might support. Being empirical studies, they cannot rule out couples matching on other characteristics like income, height or health, which are correlated with education, from driving results. We contribute to this literature by randomly assigning high and low education and income levels to 388 artificial male and female profiles on a large online dating website in China. We then counted thousands of ‘visits’ – clicks on abbreviated profiles, which included education and income information, from search engine results. We found that men’s visits to female profiles were unaffected by the profile’s assigned education level, while women’s visits to male profiles increase with the profile’s education. However, that increase was not increasing on the women’s own level of education, though their visits to the higher income male profiles was increasing on their own education. Our findings suggest that the relationship public goods that stem from a common level of high education are not at the forefront of either men’s or women’s minds before their first dates, when one might expect such goods to play a critical role in the decision to develop the relationship further. [ABSTRACT FROM AUTHOR]

This paper analyses the relationship between the Gini coefficient and the marriage rate to find whether assortive mating may exist in USA. The author uses the panel data of 50 states in USA for 30 years to run a fixed state-effect model and a fixed time-effect model. The paper contains robustness check for the fixed effect model. The results provide strong evidence that the Gini coefficient has a negative effect on the marriage rate and the assortive mating may still exist in USA. [ABSTRACT FROM AUTHOR]

Assortative mating in phenotype in human marriages has been widely observed. Using genome-wide genotype data from the Framingham Heart study (FHS; number of married couples = 989) and Health Retirement Survey (HRS; number of married couples = 3,474), this study investigates genomic assortative mating in human marriages. Two types of genomic marital correlations are calculated. The first is a correlation specific to a single married couple “averaged” over all available autosomal single-nucleotide polymorphism (SNPs). In FHS, the average married-couple correlation is 0.0018 with p = 3×10−5; in HRS, it is 0.0017 with p = 7.13×10−13. The marital correlation among the positively assorting SNPs is 0.001 (p = .0043) in FHS and 0.015 (p = 1.66×10−24) in HRS. The sizes of these estimates in FHS and HRS are consistent with what are suggested by the distribution of the allelic combination. The study also estimated SNP-specific correlation “averaged” over all married couples. Suggestive evidence is reported. Future studies need to consider a more general form of genomic assortment, in which different allelic forms in homologous genes and non-homologous genes result in the same phenotype. [ABSTRACT FROM AUTHOR]

The reversal of the gender gap in education has potentially far-reaching consequences for marriage markets, family formation, and relationship outcomes. One possible consequence is the growing number of marriages in which wives have more education than their husbands. Past research shows that this type of union is at higher risk of dissolution. Using data on marriages formed between 1950 and 2004 in the United States, we evaluate whether this association has persisted as the prevalence of this relationship type has increased. Our results show a large shift in the association between spouses’ relative education and marital dissolution. Specifically, marriages in which wives have the educational advantage were once more likely to dissolve, but this association has disappeared in more recent marriage cohorts. Another key finding is that the relative stability of marriages between educational equals has increased. These results are consistent with a shift away from rigid gender specialization toward more flexible, egalitarian partnerships, and they provide an important counterpoint to claims that progress toward gender equality in heterosexual relationships has stalled. [ABSTRACT FROM PUBLISHER]

Has there been an increase in positive assortative mating? Does assortative mating contribute to household income inequality? Data from the United States Census Bureau suggests there has been a rise in assortative mating. Additionally, assortative mating affects household income inequality. In particular, if matching in 2005 between husbands and wives had been random, instead of the pattern observed in the data, then the Gini coefficient would have fallen from the observed 0.43 to 0.34, so that income inequality would be smaller. Thus, assortative mating is important for income inequality. The high level of married female labor-force participation in 2005 is important for this result. [ABSTRACT FROM AUTHOR]

We use incidence data from the 1980 Census and 2008 American Community Survey to track recent trends in interracial marriage. Intermarriage with Whites increased rapidly among Blacks but stalled among Asians and American Indians. Black-White intermarriage increased threefold over 1980-2008, independent of changing socioeconomic status, suggesting declining social distance between Blacks and Whites. Marriages between the U.S.- and foreign-born populations also grew rapidly. Marriages to immigrants increased fivefold among U.S.-born Asian women and doubled among U.S.-born Latinas since 1980. Out-marriage to Whites also was higher among self-identified biracial than monoracial individuals, but these differences were smallest among Blacks. Interracial couples were overrepresented among cohabiting couples. Finally, log-linear models provide evidence of growing racial exogamy, but only after adjusting for changing demographic opportunities for intermarriage. Marriages between U.S.- and foreign-born coethnics have been driven by new immigration while slowing the upward trajectory of interracial marriage in America. [ABSTRACT FROM AUTHOR]

We examine the hypothesis that environmental transmission is a significant factor in individual differences for Neuroticism among 45,850 members of extended twin kinships from Australia (N = 20,945) and the United States (N = 24,905). To this large data set we fitted a model estimating genetic and environmental components of variance and gene-environmental covariance to examine the causes of individual differences in Neuroticism. For the combined sample we reject models including environmental transmission, shared environment, and a special twin environment in favor of more parsimonious genetic models. The best-fitting model involved only modest assortative mating, nonshared environment, and both additive and nonadditive genetic components. We conclude, first, that there is no evidence for environmental transmission as a contribution to individual differences in Neuroticism in these replicated samples, drawn from different continents, and, second, that a simple genetic structure underlies familial resemblance for the personality trait of Neuroticism. It is interesting that, despite the opportunity provided by the elaborate design and extensive power of our study, the picture revealed for the causes of individual differences in Neuroticism is little more complex than that found from earlier, simpler designs applied to smaller samples. However, this simplicity could not have been confirmed without using a highly informative design and a very large sample. [ABSTRACT FROM AUTHOR]

Social norms regarding who marries whom have changed dramatically in the United States across the 20th century. These changes may influence the level of genetic similarity between spouses. This study investigates whether genetic similarity in height between husband and wife was influenced by a historical transition in spouse selection criteria. The great transition from the companionate marriage to the individualized marriage occurred in the 1960s. In the companionate marriage, husband and wife chose each other as companions, and the emphasis was on playing marital roles well: husbands being good breadwinners and wives being good homemakers. In the individualized marriage, the emphasis switched to individual feelings, and as a result, when choosing their partners people tended to pay less attention to height, suggesting a smaller genetic correlation for height between spouses. Using data from the Health and Retirement Study, we found that the genetic correlation for height declined substantially in the individualized marriage. We conducted a number of analyses to test for the confounding effects of cohort and age and to address population stratification, selection issues, and genetic relatedness between spouses. Evidence suggests that the effect of this transition is robust.

The growing economic similarity of spouses has contributed to rising income inequality across households. Explanations have typically centered on assortative mating, but recent work has argued that changes in women's employment and spouses' division of paid work have played a more important role. We expand this work to consider the critical turning point of parenthood in shaping couples' division of employment and earnings. Drawing on three U.S. nationally representative surveys, we examine the role of parenthood in spouses' earnings correlations between 1968 and 2015. We examine the extent to which changes in spouses' earnings correlations are due to (1) changes upon entry into marriage (assortative mating), (2) changes between marriage and parenthood, (3) changes following parenthood, and (4) changes in women's employment. Our findings show that increases in the correlation between spouses' earnings prior to 1990 came largely from changes between marriage and first birth, but increases after 1990 came almost entirely from changes following parenthood. In both instances, changes in women's employment are key to increasing earnings correlations. Changes in assortative mating played little role in either period. An assessment of the aggregate-level implications points to the growing significance of earnings similarity after parenthood for rising income inequality across families., (Copyright © 2021 The Authors.)

The article discusses a study by Dalton Conley and colleagues which investigated the effect of assortative mating and differential fertility on the genetic makeup of the U.S. population.

The Internet has now become a habitual channel for finding a partner, but little is known about the impact of this recent partnership market on mate selection patterns. This study revisits the supply side perspective on assortative mating by exploring the role played by online venues in breeding educational, racial/ethnic and religious endogamy. It compares couples that met online (through either online dating platforms, Internet social networking, Internet gaming website, Internet chat, Internet community, etc.) to those that met through various offline contexts of interaction. Using unique data from the U.S. for the year 2009 and data from Germany collected between 2008 and 2014, I run log-multiplicative models that allow for the strength of partners' association to vary along meeting settings. Results reveal that the Internet promotes weaker couple endogamy compared to conventional contexts typically known to foster endogamy, such as school, family, friends, or religious venues., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objective: Early-onset bipolar (BP) disorder and other poor prognosis characteristics are more prevalent in patients from the United States than from the Netherlands and Germany (abbreviated as Europe). We explored the impact of parental loading for affective illness on onset and other characteristics of BP disorder., Method: Parental history for unipolar (UP) and bipolar (BP) depression and course of illness characteristics were obtained from self-report in adults (average age 42) with BP disorder. Illness characteristics were examined by χ2 and multinomial logistic regression in relationship to the degree of parental loading: i) both parents negative; ii) one UP disorder; iii) one with BP disorder; and iv) both affected., Results: After controlling for many poor prognosis factors, compared with those from Europe, patients from the United States had more iii) one parent with BP disorder and iv) both parents affected. An early age of onset of BP disorder was independently associated with this increased parental loading for affective disorder., Conclusion: Parental history of BP disorder and both parents with a mood disorder were more common in the United States than Europe and were associated with an early onset of bipolar disorder and other poor prognosis characteristics. These findings deserve replication and exploration of the potential mechanisms involved and their therapeutic implications., (© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)