What do maggots have to say about your political leanings? A lot more than you might think.
A strange new study shows that the way your brain responds to photos of maggots, mutilated carcasses, and gunk in the kitchen sink gives a pretty good indication of whether you're liberal or conservative.
"Remarkably, we found that the brain's response to a single disgusting image was enough to predict an individual's political ideology," Read Montague, a Virginia Tech Carilion Research Institute psychology professor who led the study, said in a written statement.
For the study, 83 men and women viewed a series of images while having their brains scanned in a functional MRI (fMRI) machine. The images included the disgusting photos described above, along with photos of babies and pleasant landscapes.
Afterward, the participants were asked to rate how grossed out they were by each photo. They also completed a survey about their political beliefs, which included questions about their attitudes toward school prayer, gun control, immigration, and gay marriage.
There was no significant difference in how liberals and conservatives rated the photos. But the researchers noted differences between the two groups in the activity of brain regions associated with disgust recognition, emotion regulation, attention and even memory. The differences were so pronounced that the researchers could analyze a scan and predict the person's political leaning with 95 percent accuracy.
While the researchers believe these differences in our reactions to disgusting images are likely "hard-wired" into our brains--that is, inherited from our parents--they argue genes might affect our political views similar to the way they affect our height.
"Genetics predetermines height -– but not fully," Montague said in the statement. "Nutrition, sleep, and starvation can all change someone's ultimate height. But tall people's children tend to be tall, and that's a kind of starting point."
Montague added that accepting that our brains are built to have differing political views could help ease political tensions.
"If we can begin to understand that some automatic reactions to political issues may be simply that -- reactions -– then we might take the temperature down a bit in the current boiler of political discourse," he said.
The study will be published in an upcoming issue of the journal Current Biology.