Rose McDermott of Brown University; Peter K. Hatemi of Pennsylvania State University; and Lindon J. Eaves, Kenneth S. Kendler and Michael C. Neale of Virginia Commonwealth University examined the different ways fear manifests in individuals and its correlation to political attitudes
The study, published in the American Journal of Political Science, found people who have a greater genetic liability to experience higher levels of social fear tend to be more supportive of anti-immigration and pro-segregation policies.
"It's not that conservative people are more fearful, it's that fearful people are more conservative," McDermott said in a statement. "People scared of novelty, uncertainty, people they don't know, and things they don't understand, are more supportive of policies that provide them with a sense of surety and security."
However, the researchers made clear, genetics played only part of the role in influencing political preferences.
Education had an equally large influence on out-group attitudes, the researchers said.
The researchers used a large sample of related individuals, including twins, siblings and parents and children, and assessed their propensity for fear using standardized clinically administered interviews.
Looking at subjects who were related to one another, the researchers identified influences such as environment and personal experience and found that some individuals also possessed a genetic propensity for a higher level of baseline fear. Such individuals are more prepared to experience fear in general at lower levels of threat or provocation, the study said.
"We can roll our eyes and get really frustrated at Congress for being paralyzed, but we're applying a rational perspective to it because we're detached," McDermott said. "A lot of what's driving the paralysis and disagreement has to do with emotional factors that are not necessarily amenable to or easily shifted by rational arguments."