Genetic predispositions and family environments both shape extreme political views, but they do so in entirely different ways depending on the specific type of attitude. A new study reveals that a desire for social conformity is heavily influenced by household upbringing, while a preference for group dominance stems more from outside personal experiences. The research was published in Behavior Genetics.
Political scientists and psychologists often examine two distinct personality traits to understand polarized socio-political attitudes. The first is Right-Wing Authoritarianism. This concept describes a person’s preference for strict adherence to social conventions, collective security, and obedience to authority.
The second concept is Social Dominance Orientation. This captures a person’s desire for group-based hierarchies and the belief that their own social group is inherently superior to others. Both traits reliably predict prejudice, support for extreme political movements, and a tolerance for discrimination.
Researchers want to know why people develop these distinct views in the first place. Past research has shown that both biological genetics and life experiences play a role in shaping them. It has remained largely unknown whether the specific environmental and genetic sources differ between the two traits.
Psychologists Christian Kandler and Jana Instinske of Bielefeld University in Germany, along with sociologist Edward Bell of the University of Western Ontario, wanted to map exactly how these influences combine. They also aimed to see if the roots of these political attitudes shift as people grow from adolescence into young adulthood.
The researchers analyzed data from a large study of 1,440 German families. This group included identical and fraternal twins, their parents, and their non-twin siblings, encompassing more than 5,000 individuals. The twins belonged to three distinct age cohorts averaging 15, 21, and 27 years old.
Participants answered survey questions designed to measure their levels of both authoritarianism and social dominance. By comparing the attitude similarities between identical twins, who share all their genes, and fraternal twins, who share about half, the team could estimate the mathematical contribution of genetics.
Adding parents and non-twin siblings to the analysis allowed the researchers to account for the specific environments families create. It also let them measure assortative mating. This is the well-documented tendency of people to marry partners who share similar political and social views.
The results showed that genetics shape about the same total amount of variance for both personality traits. The genetic components themselves differed slightly in their structure. Authoritarianism was influenced by both additive genetics, which are straightforward traits passed directly from parents, and nonadditive genetics, which involve complex interactions between different genes.
Social dominance was driven entirely by additive genetic factors. Beyond that basic genetic contribution, the two political orientations diverged completely in their environmental origins. Authoritarianism showed a strong connection to family inheritance and upbringing.
The data indicated that parents who favor social conformity tend to choose partners who feel the same way. These parents then pass down both genetic predispositions and a home environment that reinforces those exact traditionalist views. Researchers refer to this combined biological and environmental inheritance as a passive genotype-environment correlation.
In this scenario, children receive genes that might make them lean toward conformity, and they are simultaneously raised in a household that actively promotes obedience and tradition. Social dominance showed almost no link to this kind of passive family inheritance.
The tendency for parents to match with partners based on dominance preferences was lower, and the home environment played a negligible role in shaping the trait in their children. Instead, a person’s preference for group hierarchy was heavily shaped by their own unique, individual experiences outside the family home.
The researchers suggest this divergence makes sense based on what the traits represent. Authoritarianism involves moral regulation and conformity, which are central to keeping a family unit cohesive. Because these values dictate household rules and religious traditions, they heavily influence mate selection and parenting.
By contrast, a preference for social dominance usually applies to intergroup competition in the broader outside world. A belief in societal hierarchy is less relevant to daily household dynamics, making it less likely to be directly programmed by the family environment.
The team also looked at how these influences changed as the twins aged. They initially suspected that the impact of the family environment would fade as adolescents grew into adults and selected their own surroundings. They hypothesized that genetics would play a larger role as adults sought out social circles and news sources that matched their natural predispositions.
Instead, the data pointed in the opposite direction. For both traits, the total genetic influence remained relatively stable across the age groups. The influence of environments shared specifically by the twins actually increased from adolescence to adulthood.
This twin-specific shared environment was essentially nonexistent for 15-year-olds but became highly relevant for 21-year-olds and 27-year-olds. The researchers suspect that as young adults become eligible to vote, they might engage in more political discussions with their peers and twin siblings. This co-development process could amplify shared social influences during the exact years when political identities solidify.
A few limitations shape how these findings should be interpreted. The study compared different age groups at a single point in time, rather than tracking the same individuals across their entire lives. This makes it difficult to separate genuine developmental changes from generational effects related to the specific time period in which a given cohort was born.
The statistical tests did not yield statistically significant differences between the age cohorts for many of the mathematical model parameters. The researchers note that an even larger sample might be needed to confirm other age-related trends. The study also relied on relatively short survey measures, which can sometimes limit the precision of personality evaluations.
Additionally, the mathematical models required the researchers to assume that genetic and environmental variances remain identical across different generations, which may not perfectly reflect reality given shifting cultural norms. Understanding these origins provides a foundation for making sense of political polarization.
The study, “Sources of Differences in Right-Wing Authoritarianism and Social Dominance Orientation from Adolescence to Adulthood: A Multi-Cohort Twin Family Study,” was authored by Christian Kandler, Jana Instinske, and Edward Bell.