Researchers from the University of Amsterdam conducted a study using MRI scans of almost 1,000 Dutch people in order to investigate the connection between brain structure and political ideology. They found that there is indeed a connection between brain structure and ideology, but it is smaller than expected. The study showed that differences in the brain are linked to something as abstract as ideology, which the researchers found to be remarkable.
The study was influenced by a previous study of 90 English students in 2011 that found a connection between brain structure and ideology. The research team at the University of Amsterdam aimed to conduct the largest replication study to date in order to further explore this relationship. The MRI scans of 975 Dutch people aged 19 to 26 were analyzed and linked to questionnaires about ideology, representing a cross-section of the Dutch population in terms of education and political preference.
The study revealed that the amygdala of conservative individuals is slightly larger, similar to the findings in the English study. However, the difference in the size of the amygdala was minimal, equivalent to the size of a sesame seed. This suggests that there is a connection between brain anatomy and ideology at some level, but it is indirect. The researchers were surprised by the consistency of this finding in a larger and more representative sample.
Despite the findings regarding the amygdala, no relationship was found between another brain area, the anterior cingulate cortex, and ideology. The researchers also found that there is no simple dichotomy when it comes to political ideology in the brain, debunking the notion of “blue” and “red” brains in the American context. Ideology is a broader concept, and there are fewer connections between brain and ideology than previously thought.
The study also revealed that ideology itself is more complex than previously assumed. Participants who voted for the SP, a Dutch political party with radical left-wing economic positions but conservative social values, were found to have a larger amygdala on average than participants who identified with more progressive parties. This complexity highlights the diverse nature of political ideology and its relationship to brain structure.
In addition to the amygdala, the researchers identified connections between ideology and other brain areas. For example, a connection was found between the volume of the right fusiform gyrus, responsible for facial recognition, and more right-wing positions on social and economic issues. The reasons for these connections remain to be explored further. Overall, the study adds new insights to the understanding of the relationship between brain structure and political ideology, highlighting the complexity of this phenomenon.