While both genetic and environmental factors play a role in the stability of political ideology, changes in these beliefs over time are largely driven by environmental influences, according to a recent study published in the journal Personality and Individual Differences. The study’s findings offer a nuanced view of how our political views are formed, maintained, and transformed, shedding light on the enduring debate over nature versus nurture in shaping our beliefs.
The motivation behind this study lies in a long-standing question in psychology and political science: Why do some people maintain consistent political views throughout their lives, while others change their beliefs? Previous research has established that political ideology is influenced by both environmental factors, such as life experiences and socialization, and genetic factors, with studies suggesting that approximately 40% of the variation in political ideology can be attributed to genetic factors.
However, less is known about what drives changes in these beliefs over time. This study aimed to fill that gap by examining the relative contributions of genetics and environment to both the stability and change of political ideology.
To explore the stability and change in political ideology over time, the researchers utilized data from the Danish Twin Registry, the world’s oldest nationwide twin registry. The study included 2,471 pairs of twins who were surveyed at three different points in time: 2009, 2012, and 2019. The participants, who were born between 1970 and 1989, provided responses to a series of questions designed to measure their social and economic ideologies.
The twin study design is particularly valuable in this context because it allows researchers to disentangle the effects of genetics (by comparing monozygotic, or identical, twins who share 100% of their genes, with dizygotic, or fraternal, twins who share about 50% of their genes) and environment on political beliefs. By comparing the similarities and differences in political attitudes between these two types of twins, the researchers could estimate the relative contributions of genetic and environmental factors to ideological stability and change.
The study measured social ideology through questions related to topics such as crime, homosexuality, and national customs, while economic ideology was assessed through questions about taxes, income inequality, and social reforms. The researchers combined these responses into indices representing overall social and economic ideologies, which were then analyzed using statistical models to understand how these attitudes changed over the ten-year period and what factors influenced these changes.
The study’s findings reveal a complex picture of how political ideologies develop and change over time. The researchers found that both genetics and environment contribute to the stability of social and economic ideologies. In other words, whether a person’s political views remain consistent over time is influenced by both their genetic predispositions and the environment they are exposed to, including family upbringing, socialization, and life experiences.
However, when it comes to changes in ideology over time, the study found that environmental factors are the primary drivers. For social ideology, the shared environment—factors that twins experience together, such as parental influence and the broader social environment—was the key factor in explaining changes. This suggests that shifts in social beliefs are more likely to be influenced by collective experiences shared within families or communities.
In contrast, changes in economic ideology were influenced by both shared and unique environmental factors. Unique environmental factors are experiences that differ between twins, such as individual life events like unemployment or personal interactions that one twin might have but the other does not. This finding indicates that changes in economic beliefs may be more susceptible to personal experiences and individual circumstances.
Interestingly, the study found no evidence that genetic factors play a role in the changes in political ideology over time. While genetic predispositions contribute to where people start in terms of their ideological leanings, these predispositions do not seem to influence how or whether their beliefs change over time.
“Put simply, changes in social ideology appear to be attributable to common environmental factors (e.g., socialization and peer group influences), while changes in economic ideology are affected by both the shared and nonshared experiences of twins. Overall, while ideological starting values (i.e., the propensity to hold left or right leaning attitudes) are affected by genetic predispositions, our results illustrate that changes in these attitudes are not,” the researchers wrote.
While this study provides new insights into the factors that contribute to the stability and change of political ideology, it also has some limitations that future research could address. One limitation is the study’s focus on a specific population — Danish twins — who are relatively homogenous in terms of ethnicity and cultural background. This raises the question of whether the findings would be the same in more diverse populations or in different cultural contexts.
“We need more research on the extent to which our findings generalize to other contexts,” the researchers said. “Are the relationships between biologically informed starting values and socially generated changes a general feature or specific to the Danish context? Understanding this could help bridge the divide between different schools of thought on how attitudes form and change over time and could help provide a better understanding of the role of contextual factors in shaping attitude stability and change.”
The study, “Genetic and environmental influences on the stability of political attitudes,” was authored by Stig Hebbelstrup Rye Rasmussen, Aaron Weinschenk, Aleksander Ksiazkiewicz, Jacob von Bornemann Hjelmborg, Asbjørn Sonne Nørgaard, and Robert Klemmensen.