The Real Roots of Political Attitudes?

The New York Times and other news outlets are touting a new Brookings Institution publication which casts doubt on the right-wing talking point that university professors sway their students' political ideas. Most people's political leanings appear by their mid-teens, researchers found, well before college. This is hardly a surprise to folks who make their own observations. The biggest influence on a person's politics is, and always was, one's family.

More intriguing was Eve LaPlante's article in the Sunday Boston Globe about recent research showing a biological, perhaps genetic, basis for conservative or liberal leanings.

[Political scientist John] Hibbing, a leading figure in the new field, said a turning point was a Rice University study of identical and fraternal twins, published three years ago in the American Political Science Review. Using data from a large-scale study of thousands of sets of twins, researchers discovered that identical twins are far more likely than fraternal twins to share political attitudes on busing, foreign aid, school prayer, gay rights, pacifism, nuclear power, and many other issues. "Political and social attitudes" are "40-50 percent heritable," the study reported. . . .

Inside the political physiology laboratory at the University of Nebraska, researchers project a series of 30 images on the wall. Some images are threatening--a gruesome wound, a spider on someone's face. Other images, such as a bunny or a bowl of fruit, are not. Now and then a machine emits a loud sound like a gunshot. . . .

As the images and noises are presented, a machine records the subject's physical responses. An electrode above her eye measures automatic muscle movements that make up the "blink startle" response. A lead attached to her finger measures "skin conductance," the amount of perspiration on the skin, another physiological sign of stress.

After examining 46 such subjects, researchers found a strong correlation between subjects' political attitudes and their physiological responses to threat. People who showed more "blink startle" and perspiration after a threatening stimulus tended to cluster on the right politically. They advocated capital punishment, school prayer, and defense spending, and they supported the Iraq war.

In contrast, liberals--who supported "less protectionist" policies such as gun control, open immigration, and increased foreign aid--showed significantly less physical response to the threatening stimuli. While education had some effect on the results, subjects' blink and skin-conductance responses were much better predictors of their political attitudes. And the degree to which a person was startled by threatening stimuli indicated how much he or she advocated policies that protect society from external and internal threats such as wars and crime. [Hibbing and his colleagues published their results in the 19 Sept 2008 issue of Science.] . . .

Meanwhile, other researchers are using brain-wave studies to pursue the physiological correlates of political orientation. A group at New York University and UCLA recently reported they found significant, measurable differences between the brain waves of liberals and conservatives. In the experiment, researchers attached electrodes to the scalps of 43 subjects who had answered a questionnaire of political attitudes. Subjects were asked to perform a simple task: press a button whenever the letter "M" appears on a screen, but do nothing when anything else appears on the screen. The letter "M" appeared 80 percent of the time, so the occasional appearance of a "W" caused subjects to experience "conflict monitoring"--a neural mechanism for detecting that a habitual response is not desired.

Liberals and conservatives performed similarly on the habitual task, which is "super easy," according to lead researcher David Amodio, a psychologist at New York University. However, liberals performed much better than conservatives on the unexpected responses. Whenever the unexpected "W" appeared, electroencephalogram (EEG) records showed greater "conflict-related neural activity" in liberals. This brain activity, localized to the limbic system, underlies the ability to "detect that something's wrong with an ongoing pattern of behavior and then change it," according to Amodio, who linked "greater liberalism" to this region of the brain. [Amodio's study appeared in Nature Neuroscience in 2007.]

Time reported on Hibbing's study in September. The National Science Foundation has a video interview with him.