Wthis is where our personal politics come from? Does it trace back to our childhood, the views that surround us, the circumstances in which we were brought up? Is it all about nurture – or does nature have a say through the subtle levers of DNA? And where, in all this, is the brain?
Scientists have delved seriously into the roots of political belief over the past 50 years, spurred by the rise of sociobiology, the study of the biological basis of behavior, and made possible by modern tools like brain scanners and genome sequencers. The field is making progress, but teasing out the biology of behavior is never simple.
Take a study published last week. Researchers in Greece and the The Netherlands Examined MRI scans of nearly 1,000 Dutch people who answered questionnaires about their personal politics.
The work was a replication study, designed to see if the results of a small 2011 studyoddly enough at the behest of actor Colin Firth, stood up. Firth’s study, carried out at UCL, reported structural differences between conservative and liberal brains. Conservatives, on average, had a larger amygdala, a region linked to threat perception. Liberals, on average, had a larger anterior cingulate cortex, a region involved in decision making.
In the latest study of Dutch people, the researchers found no sign of a larger anterior cingulate cortex in liberals. However, they found evidence for a very slightly larger amygdala in conservatives. The MailOnline stated evidence that Conservatives were more “compassionate”, but later changed their headline note that the study said nothing about compassion.
It’s worth looking at the size of the difference the scientists found. When Dr Steven Scholte, a co-author of the study at the University of Amsterdam, did the calculations, he found that the amygdala of a conservative was on average larger than that of a liberal by the volume of one sesame seed. This is three times smaller than the 2011 study found. In their writing iSciencethe researchers said it was “critical to approach these findings with caution, to avoid promoting misconceptions and stereotypes”.
So what does that mean? Do people with larger amygdalas feel more threatened and therefore tend toward conservatism? Or do conservatives feel more threatened and develop a slightly larger amygdala as a result? “It is impossible to know with the help of such correlational data what causes what,” said Dr. Diamantis Petropoulos Petalas, the first author of the study.
Social environment is clearly one of the most powerful shapers of people’s politics. Political values and beliefs can emerge in early life, especially when children have politically engaged parents or caregivers. But political ideology continues to evolve with education and into adulthood as family influence declines. Higher education is consistently linked to more liberal views, particularly on issues such as immigration, civil rights and gender equality.
Perhaps most interesting is the role of genetics. Studies of twins show that political ideology over 40% hereditary. But again, what does that mean? These are population level measures after all. It is not that 40% of a person’s beliefs are formed by genetics and 60% by environment. “It tells you the extent to which differences between people are due to genetic factors,” said Prof Aaron Weinschenk, a political scientist at the University of Wisconsin, Green Bay. “It’s not an estimate about an individual.”
How genetics affects people’s politics is similarly nuanced. Researchers have not, and do not expect, to find a Tory gene or a Democratic gene. Rather, says Tobias Edwards at the University of Minnesota Twin Cities, genes work indirectly through personality and other factors such as how long people spend in education, their income and intelligence. “We should not expect there to be any specific genes for liberalism or conservatism, but many genetic variants of infinitesimal effects, acting indirectly through other traits,” he said.
Edwards and his colleagues reported this earlier this year genetics can be used to predict political tendencieswith more intelligent siblings in families inclined to more liberal politics. But the relationship with party loyalty is much more complex, Edwards said. As he points out, extraordinarily intelligent people are found left and right.
Another mistake would be to equate intelligence with sensible values and opinions. “If we look back over history, we can see that intelligent individuals are attracted to all kinds of different and often conflicting ideas,” Edwards said. “Intellectuals flirted with and were seduced by dangerous ideologies and tyrannical regimes. Very smart people have believed ideas that are completely stupid.”
