Why do people have the attitudes they do toward social issues such as welfare, abortion, immigration, gay rights, school prayer, and capital punishment? The conventional explanations have to do with their economic circumstances, families, friends, and educations. But new research suggests that people with radically different social attitudes also differ in certain automatic fear responses. Political scientists say the work is evidence that certain attitudes are conditioned by fundamental traits of temperament, which could help explain why it's hard to get a donkey or an elephant to change its coloring.
Quite a bit is known about the physiology of response to threat, and some of this can be measured by simple noninvasive tests. So the researchers, headed by Douglas Oxley of the University of Nebraska, Lincoln, decided to test the idea that liberal and conservative (or "protective") social beliefs are related to individuals' sensitivity to threat.
The authors first conducted a random telephone survey of Lincoln residents to find some who held strong political opinions. Then 46 selected respondents were invited to come in to the lab and fill in questionnaires to reveal political beliefs and personality traits. Participants were then given two types of tests to measure physiological responses to threat.
First, they were attached to equipment to measure skin conductivity, which rises with emotional stress as the moisture level in skin goes up. Each participant was shown threatening images, such as a bloody face interspersed with innocuous pictures of things such as bunnies, and rise in skin conductance in response to the shocking image was measured. The other measure was the involuntary eye blink that people have in response to something startling, such as a sudden loud noise. The scientists measured the amplitude of blinks via electrodes that detected muscle contractions under people's eyes.
The researchers found that both of these responses correlated significantly with whether a person was liberal or conservative socially. Subjects who had expressed a high level of support for policies "protecting the social unit" showed a much larger change in skin conductance in response to alarming photos than those who didn't support such policies. Similarly, the mean blink amplitude for the socially protective subjects was significantly higher, the team reports in tomorrow's issue of Science. Co-author Kevin Smith says the results showed that automatic fear responses are better predictors of protective attitudes than sex or age (men and older people tend to be more conservative).
How are body and belief connected? The authors point out that family and twin studies have revealed strong genetic influences both for liberal-versus-conservative views and for people's sensitivity to threat. They speculate that the correlation could have something to do with the patterns of neural activity surrounding the amygdala, the seat of fear in the brain.
"These findings are extremely important," says political scientist James Fowler at the University of California, San Diego, who has been doing research linking certain gene variations to political activity. "In essence, the authors have filled in a 'missing link' between genes and brains on the one hand and psychological personalities and political attitudes on the other." He adds that the subject pool is limited to "a handful of white subjects from Nebraska, ... but many great ideas start with a simple test."