Reaction to Mutilated Animal Imagery Accurately Predicts Political Leanings

One of the most fascinating
things about political ideology is that it’s likely much more
genetic than most people realize. Of course “nurture” matters, but
there’s strong evidence that people are also born with certain
features and personality traits that predispose them toward leaning
liberal, conservative, or libertarian. A new study suggests that
unconscious reactions to a single “disgusting image” can reliably
predict whether someone identifies as liberal or
conservative. 

The
study, published in the most recent issue of Current
Biology, relied on brain scans of people shown a series of
gross, pleasant, and neutral images. Researcher P. Read Montague, a
Virginia Tech professor and head of the school’s Human Neuroimaging
Lab, said he was inspired by research showing political affiliation
is highly heritable and how one identifies politically has deep
connections to biology, especially the way our bodies respond to
threats of “contamination” or violence.

The brain scans revealed that, indeed, the way one’s neurons
fired in response to gross-out imagery was a pretty damn good
indication of whether one identified as liberal or conservative.
While responses to the pleasant and neutral images were predictive
of nothing, responses to an image of a mutilated animal body were
split neatly down political lines.

“A single disgusting image was sufficient to predict each
subject’s political orientation,” said Montague. “I haven’t seen
such clean predictive results in any other functional imaging
experiments in our lab or others.” The results “suggest that
important foundational parts of political attitudes ride on top of
preestablished neural responses,” he said.

Self-reported responses to the imagery were not an accurate
predictor of political persuasion. 

“These results provide strong support for the idea that
fundamental neural processing differences that emerge under the
challenge of emotionally evocative stimuli may serve to structure
political beliefs in ways formerly unappreciated,” the researchers
concluded. 

Ronald Bailey has written here previously about research showing
political conservatives
are more easily grossed out. Other research has shown that
those with
low sensitivity to disgust tend to be liberals or
libertarians.