Ideas for scientific experiments come from all sorts of places (and fewer of them originate in the lab than you might think). A study on political orientation and brain structure, published in Current Biology, for example, got its start when the actor Colin Firth—credited as a co-author on the paper—was guest-editing a BBC Radio 4 program called “Today.” “This struck me as an opportunity to explore things which compel me…but about which I’m perhaps not sufficiently informed,” he told host Justin Webb. “I…decided to find out what was biologically wrong with people who don’t agree with me and see what scientists had to say about it.” Or to put it a bit more nicely, to see if the brains of people with different political leanings were truly different.
Ryota Kanai and Geraint Rees of University College London took that idea and ran with it. They performed MRI scans of 90 college students who had been asked about their political attitudes, and then looked at various structures in the brain. They found that a greater amount of gray matter in the anterior cingulate cortex was associated with liberalism and a greater amount in the amygdala was associated with conservatism. They confirmed the finding in a second set of 28 participants. These findings are consistent with previous studies showing greater brain activity in the anterior cingulate cortex of liberals. One of the jobs of that area of the brain is to monitor uncertainty and conflicts. “Thus, it is conceivable that individuals with a larger ACC have a higher capacity to tolerate uncertainty and conflicts, allowing them to accept more liberal views,” the scientists write.