The reaction your brain has to the bloody guts and gore of a haunted house this Halloween might be linked to how you vote next week. Scientists showed a series of emotionally evocative images—either threatening, pleasant, disgusting, or neutral—to 83 volunteers as the participants lay inside MRI machines recording their brain activity. The researchers found that the areas of the brain that lit up in response to the grossest pictures—like mutilated bodies and burn victims—depended on whether the participant was more liberal or more conservative, based on a survey of political beliefs. The differences were seen in areas of the brain associated not only with disgust, but also with memory retrieval, attention, pain, and innate “gut responses.” Even the brain scan of a person looking at a single disgusting image was enough to predict their political tendencies, but more work will be needed to know exactly what these brain scan differences mean. It’s not clear that either liberals or conservatives are more squeamish than the other; the two groups had similar scores when asked to rate how grossed out they were by the pictures, or how sensitive they generally are to disgusting images, the team reports online today in Current Biology. But the results do lend credence to the idea that which way someone sways on Election Day is at least somewhat mediated by biological factors, the researchers say.