Science: About the origins of political beliefs

From time to time, the question arises about where a person's political beliefs come from. At the most basic human level there is nature (inheritance of genes) and nurture. Nurture refers to the environmental factors that influence a person's development after conception including things like upbringing, life experiences, family and social relationships and norms, culture, community, learning ability, sex, language, poverty, wealth, religion, education and epigenetics. Epigenetics refers to gene expression changes after an egg gets fertilized, e.g., exposure to lead, or PFAS or other toxic chemicals in the environment, especially effects on a fetus or young children.

Some years ago I came across two nature vs nurture estimates for the origin of personal politics. If I recall right, one estimate was that politics came about equally from nature and nurture. The other was that it was about 40% nature and 60% nurture. Being interested in this, I did some searching to see what the research says these days. 

Q: What are current estimates of the influence of nature (genes) compared to nurture on how people form their political beliefs or ideologies?

A: Genetic Influences: Twin studies found that genetic factors account for a substantial proportion of individual differences in political traits, with heritability estimates averaging around 0.50 (on a scale of 0-1). One study using data from the Minnesota Twin Study found that sociopolitical conservatism was 57% heritable for the overall population. For the most politically informed fifth of the public, the heritability of sociopolitical conservatism was estimated to be as high as 74%.

Environmental Influences: For the least politically informed half of the public, the heritability of sociopolitical conservatism was estimated to be only 29%, suggesting a stronger role for environmental influences.

Interaction of Genes and Environment: Political knowledge appears to facilitate or influence the expression of genetic predispositions in political attitudes.

The NYT wrote in 2022: In “The Law of Group Polarization,” Cass Sunstein of Harvard Law School argues this about polarization: This general phenomenon — group polarization — has many implications for economic, political, and legal institutions. It helps to explain extremism, “radicalization,” cultural shifts, and the behavior of political parties and religious organizations; it is closely connected to current concerns about the consequences of the internet; it also helps account for feuds, ethnic antagonism, and tribalism.

A 2018 article commented:

What about political orientation? Left-leaning liberals estimated a greater genetic contribution to psychiatric disorders and sexual orientation compared with conservatives, while conservatives assumed a relatively greater contribution of genes to traits like intelligence and musical ability. This led to what the researchers called "a surprising sort of 'balancing out'," meaning that individuals' accuracy did not differ by political persuasion.

The researchers believe this pattern is consistent with the idea that moral judgments are central to the political split in the USA. Right-wing participants more strongly endorsed the idea that some people have more innate aptitude than others, while the left-wing participants more strongly endorsed the idea that many stigmatized traits are largely innate and should therefore be treated with fairness and compassion, not judgment. 

 

So there was no greater biological denialism or "blank slatism" by one political wing than the other, but rather a genetic cherry-picking to suit one's own world view.

A 2022 paper commented:

First, we find that religiosity’s role on political attitudes is more heritable than social. Second, religiosity accounts for more genetic influence on political attitudes than personality. When including religiosity, personality’s influence is greatly reduced. Our results suggest religion scholars and political psychologists are partially correct in their assessment of the “culture wars” – religiosity and ideology are closely linked, but their connection is grounded in genetic predispositions.

A 2024 research paper about the genetics of right wing authoritarianism commented:

Objective: Political attitudes are predicted by the key ideological variables of right-wing authoritarianism (RWA) and social dominance orientation (SDO), as well as some of the Big Five personality traits. Past research indicates that personality and ideological traits are correlated for genetic reasons.

Results: RWA and SDO exhibit very high genetic correlation (r=0.78) with each other and some genetic overlap with the personality traits of openness and agreeableness. Importantly, they share a larger genetic substrate with political attitudes (e.g., deporting an ethnic minority) than do Big Five personality traits, a relationship that persists even when controlling for the genetic foundations underlying personality traits. 

Conclusion: Our results suggest that the genetic foundations of ideological traits and political attitudes are largely non-overlapping with the genetic foundations of Big Five personality traits.[1]

In other words, two core ideological traits of RWA and SDO have a much higher genetic association with political policy attitudes than the Big Five personality traits. The covariation of such ideological traits with policy attitudes is best explained by genetic overlap, not common socialization or nurture. Contrary to key social and political psychology theories, the data here suggests that hierarchy-related traits might form a heritable genetic package for navigating intergroup struggles over territory and resources.

The research is sometimes hard to integrate into a simple left vs right framework. This 2023 paper argues that knowledge of basic science is more important in shaping attitudes toward at least a few issues of science such as global warming than partisan politics:

It is often assumed that a primary source of contention surrounding science is political and, therefore, that partisan disagreement drives attitudes about various science topics. Other models focus on the roles of basic science knowledge and cognitive sophistication, arguing that these facilitate pro-science beliefs. To test these competing accounts, we identified a range of controversial issues ostensibly subject to potential ideological disagreement and examined the relative roles of political ideology, science knowledge, and cognitive sophistication. Results show there was actually very little partisan disagreement on a wide range of nonetheless contentious scientific issues. We also found only weak evidence for identity-protective cognition; instead, reasoning ability was broadly associated with pro-science beliefs. Two experiments that focused specifically on anthropogenic climate change found that increasing political motivations did not increase polarization among individuals who are higher in cognitive sophistication, indicating that increasing political motivations may not have as straightforward of an impact in this context as often assumed. Finally, one’s level of basic science knowledge was the most consistent predictor of people’s beliefs about science across a wide range of issues. Results suggest that educators and policymakers should focus on increasing basic science literacy and critical thinking rather than the ideologies that purportedly divide people.

In conclusion, it seems that nature or genetics seems to be more important than nurture for some or most people who score high on social dominance and authoritarianism traits. But lack of knowledge (nurture) is also an important or dominant factor for at least some people with some political issues. As a species, humans doing politics appears to be non-trivially influenced by both nature and nurture.

Footnote:

1. The Big Five personality traits are on a spectrum, with individuals scoring anywhere along a continuum, allowing for a nuanced understanding of personality rather than a simplistic categorization:

Openness to Experience: This trait reflects how open-minded and willing an individual is to new experiences. High scorers tend to be imaginative, curious, and open to new ideas, while low scorers may prefer routine and familiarity.

Conscientiousness: This dimension indicates how organized, responsible, and goal-oriented a person is. Individuals high in conscientiousness are typically diligent, disciplined, and reliable, whereas those with lower scores may be more spontaneous and less structured.

Extraversion: Extraversion measures how outgoing and energetic a person is in social settings. High extraversion is associated with sociability, assertiveness, and a tendency to seek out social interactions, while low extraversion (or introversion) is linked to being reserved and needing solitude.

Agreeableness: This trait assesses how compassionate and cooperative an individual is towards others. High agreeableness is characterized by kindness, empathy, and a desire for social harmony, while low agreeableness may reflect competitiveness or a more critical nature.

Neuroticism: Neuroticism refers to emotional stability and the tendency to experience negative emotions. Individuals high in neuroticism may be more prone to anxiety, mood swings, and emotional instability, whereas those low in this trait are generally more calm and resilient under stress