By Carina Storrs
DNA might account for some differences between liberal, conservative views, researchers say.
With the U.S. presidential campaign season heating up and Election Day drawing nearer, political science experts are saying that campaigns could one day benefit from having a deeper understanding of voters, all the way down to their DNA.
"Since about 2005, there has been a turning of the tide that genes can influence political traits," said Peter Hatemi, an associate professor of political science, microbiology and biochemistry at Pennsylvania State University.
"Most social scientists had viewed the world as a blank slate, whatever your family is, whatever you run into and your experiences, is how you develop your attitudes," he added.
Research into the genetic underpinnings of political views has grown significantly in the past eight years, Hatemi said. His comprehensive review of previous research on the role genes play in attitudes, ideologies and voting behavior, is co-authored by Rose McDermott, a professor of political science at Brown University, and appears online Aug. 27 in Trends in Genetics.
Political scientists have borrowed pages from the geneticists' book of techniques for studying medicine and psychology, but it may be how political scientists are using these approaches that will have the biggest impact on public health.
"The world revolves around politics, it doesn't revolve around schizophrenia. It's important to study because the biggest determinant of public health is going to be politics," Hatemi said.
One technique in particular involves studying identical and fraternal twins. Researchers can compare how often identical twins, who share all of their genes, and fraternal twins, who share half their genes on average, give the same answers to political questions to gauge how big of a role genes play in different categories.
Hatemi and McDermott reviewed previous twin studies and reported that about half of the variation in political traits could be explained by genetics, the other half by upbringing and environment.
Categories such as political knowledge and liberal versus conservative ideology were more likely to be influenced by genetics, whereas political party identification was strongly affected by upbringing, the researchers said.
"Questions that identify who is liberal and conservative, views on abortion and death penalty, are really strongly driven by genetics," said James Fowler, a professor of medical genetics and political sciences at the University of California, San Diego. "These are attitudes toward reproduction and survival."
Hatemi noted, "When you get to affiliations, which group you belong to, that has a lot to do with family."
Genes in general do not appear to realize their full potential to influence politics until between about 21 and 25 years of age, when children leave their parents' home, according to a study by Hatemi and his colleagues included in the review.
"The family environment is so strong that it overrides any genetic similarity, but you leave home and go on your own path," Hatemi said.
Genes can then play into where you end up getting a job and living, who you become friends with, and those experiences affect your politics, Hatemi added. Identical twins continue to be politically similar into adulthood, whereas fraternal twins diverge more.
The connection between genetics and politics is not a hard leap to make, even though the concept took time for political scientists to open up to, and has been mocked by political pundits and misunderstood by the media, Fowler said.
"Gene expression affects neurotransmitters, which affects personality, which affects political behavior," he said.
Researchers are just beginning to link variations in genes involved in the function of mood-regulating neurotransmitters, namely dopamine and serotonin, with variations in political activities, such as voting, and views.
"These are the usual suspects for any social behavior," Hatemi said.
However, there could be thousands of genes involved in something as complex as political behavior, interacting with each other in different ways, according to Hatemi.
Studies have also turned up a connection between political ideology and genes involved in olfaction, or the sense of smell. This could make sense because Hatemi's research suggests that people prefer the smell of those of similar political persuasions.
"This could be an [evolutionary] strategy to find like-minded people so you stick together long enough to procreate," Hatemi said, adding that the union of James Carville, a liberal political consultant, with Mary Matalin, a conservative, is an "anomaly."
Although this kind of research is not actually going to supply politicians with information about your genes, it could help politicians indirectly to understand how personalities and beliefs affect political arguments, Fowler said.
This all means that it may be difficult to convince some people who are genetically predisposed to hold strong views on hot-button issues to change their minds -- even in the face of clear evidence, Fowler said. "The more we understand these different thought processes, the more we can tailor messages and do a better [job] of explaining to people what is true and not true," he said.