We introduce multi-trait analysis of GWAS (MTAG), a method for joint analysis of summary statistics from genome-wide association studies (GWAS) of different traits, possibly from overlapping samples. ...We apply MTAG to summary statistics for depressive symptoms (N
= 354,862), neuroticism (N = 168,105), and subjective well-being (N = 388,538). As compared to the 32, 9, and 13 genome-wide significant loci identified in the single-trait GWAS (most of which are themselves novel), MTAG increases the number of associated loci to 64, 37, and 49, respectively. Moreover, association statistics from MTAG yield more informative bioinformatics analyses and increase the variance explained by polygenic scores by approximately 25%, matching theoretical expectations.
Inspired by recent studies on personality and political attitudes and behaviour we use the Big Five approach to assess the influence of a comprehensive set of personality traits on political ...tolerance. Our study is based on surveys in Bhopal in India and Lahore in Pakistan. We find that all Big Five traits – openness, conscientiousness, extraversion, agreeableness and neuroticism – are significantly related to individuals’ willingness to grant political rights to groups they dislike in one or both countries. As one of only a few studies examining the relationship between the Big Five traits and political attitudes and behaviour outside a Western context, these findings demonstrate the importance of also paying attention to personality traits when studying contexts where situational factors such as political violence, poverty, and severe inequalities might be expected to be the main influence on individuals’ behavioural choices.
One of the clearest results in previous studies on social trust is the robust positive relationship with educational attainment. The most common interpretation is that education has a causal effect ...on social trust. The theoretical argument and empirical results in this article suggest a different interpretation. We argue that common preadult factors such as cognitive abilities and personality traits rooted in genes and early-life family environment may confound the relationship between educational attainment and social trust. We provide new evidence on this question by utilizing the quasi-experiment of twinning. By looking at the relationship between education and social trust within monozygotic (MZ) twin pairs, we are able to avoid potential confounders rooted in genetic factors and common environmental influences because the monozygotic twins share both. The results suggest that when controlling for such familial factors the estimated effects of education on social trust are close to zero and far from reaching statistical significance. Further analyses show that the relationship between education and social trust largely is driven by common genetic factors.
Recent research has demonstrated that genetic differences explain a sizeable fraction of the variance in political orientations, but little is known about the pathways through which genes might ...affect political preferences. In this article, we use a uniquely assembled dataset of almost 1,000 Swedish male twin pairs containing detailed information on cognitive ability and political attitudes in order to further examine the genetic and environmental causes of political orientations. Our study makes three distinct contributions to our understanding of the etiology of political orientations: (1) we report heritability estimates across different dimensions of political ideology; (2) we show that cognitive ability and political orientations are related; and (3) we provide evidence consistent with the hypothesis that cognitive ability mediates part of the genetic influence on political orientations. These findings provide important clues about the nature of the complex pathways from molecular genetic variation to political orientations.
A core part of political research is to identify how political preferences are shaped. The nature of these questions is such that robust causal identification is often difficult to achieve, and we ...are not seldom stuck with observational methods that we know have limited causal validity. The purpose of this paper is to measure the magnitude of bias stemming from both measurable and unmeasurable confounders across three broad domains of individual determinants of political preferences: socio-economic factors, moral values, and psychological constructs. We leverage a unique combination of rich Swedish registry data for a large sample of identical twins, with a comprehensive battery of 34 political preference measures, and build a meta-analytical model comparing our most conservative observational (naive) estimates with discordant twin estimates. This allows us to infer the amount of bias from unobserved genetic and shared environmental factors that remains in the naive models for our predictors, while avoiding precision issues common in family-based designs. The results are sobering: in most cases, substantial bias remains in naive models. A rough heuristic is that about half of the effect size even in conservative observational estimates is composed of confounding.
It is a well-established fact, from decades of research on political socialization, that the children of politically active parents are more likely to become politically active themselves. This poses ...a challenge for democracy, as it means that inequalities in political influence are reproduced across generations. The present study argues that this problem may be more severe than has hitherto been acknowledged. The reason for this is that previous research on the topic has focused almost exclusively on political transmission between parents and their children, whereas the role played by more distant forebears, such as grandparents, has been largely neglected. In this study, we use Swedish register data to analyze multigenerational associations in electoral participation. The empirical results clearly indicate that the traditional two-generation approach to the study of political transmission tends to underestimate intergenerational persistence in voting behavior and that this excess persistence has both genetic and social roots.
It is well documented that voter turnout is lower among persons who
grow up in families from a low socioeconomic status compared with
persons from high-status families. This paper examines whether
...reforms in education can help reduce this gap. We establish
causality by exploiting a pilot scheme preceding a large reform of
Swedish upper secondary education in the early 1990s, which gave
rise to exogenous variation in educational attainment between
individuals living in different municipalities or born in different
years. Similar to recent studies employing credible identification
strategies, we fail to find a statistically significant average
effect of education on political participation. We move past
previous studies, however, and show that the reform nevertheless
contributed to narrowing the voting gap between individuals of
different social backgrounds by raising turnout among those from low
socioeconomic status households. The results thus square well with
other recent studies arguing that education is particularly
important for uplifting politically marginalized groups.
This article analyzes a rich Swedish data set with information on the electoral turnout of a large sample of adoptees, their siblings, their adoptive parents, and their biological parents. We use a ...simple regression framework to decompose the parent-child resemblance in voting into pre-birth factors, measured by biological parents’ voting, and post-birth factors, measured by adoptive parents’ voting. Adoptees are more likely to vote if their biological parents were voters and if they were assigned to families in which the adoptive parents vote. We find evidence of interactions between the pre- and post-birth factors: the effect of the post-birth environment on turnout is greater amongst adoptees whose biological mothers are nonvoters. We also show that the relationships between parental characteristics, such as education, and child turnout, persist even in the absence of a genetic link between parent and child. The regression-based framework we utilize provides a basis for the integration of behavior-genetic research into mainstream political science.
Twin and adoption studies have shown that individual differences in political participation can be explained, in part, by genetic variation. However, these research designs cannot identify which ...genes are related to voting or the pathways through which they exert influence, and their conclusions rely on possibly restrictive assumptions. In this study, we use three different US samples and a Swedish sample to test whether genes that have been identified as associated with educational attainment, one of the strongest correlates of political participation, predict self-reported and validated voter turnout. We find that a polygenic score capturing individuals' genetic propensity to acquire education is significantly related to turnout. The strongest associations we observe are in second-order midterm elections in the United States and European Parliament elections in Sweden, which tend to be viewed as less important by voters, parties, and the media and thus present a more information-poor electoral environment for citizens to navigate. A within-family analysis suggests that individuals' education-linked genes directly affect their voting behavior, but, for second-order elections, it also reveals evidence of genetic nurture. Finally, a mediation analysis suggests that educational attainment and cognitive ability combine to account for between 41% and 63% of the relationship between the genetic propensity to acquire education and voter turnout.
Widespread and persistent political underrepresentation of immigrant-origin minorities poses deep challenges to democratic practice and norms. What accounts for this underrepresentation? Two types of ...competing explanations are prevalent in the literature: accounts that base minority underrepresentation on individual-level resources and accounts that emphasize political opportunity structures. However, due to the lack of data suitable for testing these explanations, existing research has not been able to adjudicate between these theories. Using registry-based microdata covering the entire Swedish adult population between 1991 and 2010 our study is the first to empirically evaluate these alternative explanations. We examine election outcomes to municipal councils over the course of six elections and find that variation in individual-level resources cannot explain immigrants’ underrepresentation. Further, when comparing immigrants and natives who face comparable political opportunity structures a large representation gap remains. Instead, we argue that discrimination by party gatekeepers plays a more significant role in perpetuating the underrepresentation of immigrants than do individual resources or structural variables.
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