Where do our personal political views come from? Do they go back to our childhood, the ideas that surrounded us, the environment we grew up in? Is it all a matter of upbringing? Or is there an innate influence through the subtle power of DNA? And where is the brain in all of this?
Spurred by the rise of sociobiology, the study of the biological basis of behavior, and armed with modern tools like brain scanners and genome sequencers, scientists have been seriously exploring the roots of political beliefs for the past 50 years. Though the field has made progress, uncovering the biology of behavior is no easy task.
Take, for example, a study published last week: Greek and Dutch researchers examined MRI scans of around 1,000 Dutch people who had completed a questionnaire about their personal political views.
The study was a replication designed to see if the results of a small study carried out in 2011 at the odd request of actor Colin Firth were correct. Firth’s study, carried out at UCL, reported structural differences in the brains of conservatives and liberals: Conservatives, on average, have a larger amygdala, an area associated with threat perception; liberals, on average, have a larger anterior cingulate cortex, an area involved in decision-making.
In a recent study of Dutch people, researchers found no sign of a larger anterior cingulate cortex in liberals, but did find evidence of a slightly larger amygdala in conservatives. MailOnline reported that there was evidence that conservatives are “more compassionate,” but then changed the headline to say the study said nothing about compassion.
The size of the difference the scientists found is remarkable: Dr. Steven Scholte, co-author of the University of Amsterdam study, calculated that conservatives’ amygdalas are, on average, about the size of a sesame seed larger than those of liberals — a third of the size of the 2011 study’s findings. “It is important to approach these findings with caution, to avoid reinforcing misconceptions and stereotypes,” the researchers wrote in an iScience article.
So what does it mean? Does it mean that people with larger amygdalas feel more threatened and tend to be more conservative? Or do conservatives feel more threatened, which results in a slightly larger amygdala? “It’s impossible to know what causes what with correlational data like this,” says Diamantis Petropoulos Petalas, PhD, the study’s first author.
Social environment is clearly one of the most powerful factors shaping people’s politics. Political values and beliefs can be formed in early childhood, especially if children have politically interested parents or guardians. But political ideology continues to evolve with education and into adulthood, when family influence wanes. Higher education is consistently associated with more liberal thinking on issues such as immigration, civil rights, and gender equality.
Perhaps most intriguing is the role of genetic factors. Twin studies suggest that political ideology is about 40% heritable. But again, what does that mean? After all, these are population-level measures; it’s not like a person’s beliefs are shaped 40% by genetics and 60% by their environment. “This tells us the extent to which differences between people are due to genetic factors,” says Aaron Weinschenk, a political scientist at the University of Wisconsin-Green Bay. “It’s not an estimate for an individual.”
The influence of genes on people’s politics is similarly subtle: Researchers have not found a gene for conservatives or a gene for Democrats, and they don’t expect to find one. Instead, Tobias Edwards of the University of Minnesota, Twin Cities, says genes act indirectly through personality and other factors, such as years of education, income and intelligence. “We shouldn’t think of it as there being a gene specific to liberalism or conservatism, but rather as lots of genetic variants with tiny effects that act indirectly through other traits,” Edwards said.
Earlier this year, Edwards and his colleagues reported that genes can be used to predict political leanings, with more intelligent siblings in families tending to lean more liberal politically. But the relationship to partisanship is much more complicated, Edwards said. As he points out, exceptionally intelligent people exist on both the right and the left.
Another mistake is to equate intelligence with sensible values and opinions. “We see through history that intelligent people have been attracted to a wide variety of often contradictory ideas,” Edwards says. “Intellectuals have been seduced and lured by dangerous ideologies and tyrannical regimes. Many smart people have believed in completely stupid ideas.”
