Here’s a provocative Election Day twist on the longstanding nature-nurture argument: Your DNA may play a role in determining whether you are politically liberal or conservative — whether, by extension, you’re inclined to vote for DFLer Mark Dayton or Republican Tom Emmer in Minnesota’s gubernatorial contest.

With caveats galore, researchers from Harvard University and the University of California San Diego report that a dopamine receptor gene, dubbed DRD4, appears to play a role in shaping political views.

It’s well established that children generally cleave to their parents’ political ideologies. And studies of twins have led scientists to think that as much as a third of the variation in political attitudes can be explained by genes.

In other words, something more basic is at play than the political rants kids hear across the dinner table night after night.

This new finding is the first to identify a specific gene-environment interaction that can be associated with the direction of a person’s political ideology, say the researchers who report their study in The Journal of Politics. Two of the researchers — UC San Diego Professor James Fowler and Dr. Nicholas Christakis of Harvard — were co-authors of the acclaimed book “Connected: The Surprising Power of our Social Networks and How They Shape Our Lives.”

Their latest findings were based on genetic data regarding 2,574 young adults who had participated in the National Longitudinal Study of Adolescent Health. The research team gathered information about the individuals’ social networks, political behavior, civic activity and political ideology.

Putting it all together, they found a complex connection: People who had a specific variation of the DRD4 gene and also had many friends in high school were far more likely to identify themselves as politically liberal.

They emphasize that the genetic variant “cannot by itself predispose someone to a liberal ideology.”

In other words, you couldn’t predict your child’s future political stripes by getting her DNA tested.

What it takes, the researchers said, is a crucial interaction of two factors — the genetic predisposition of having this particular gene variant and the environmental condition of having a lot of friends as an adolescent.

Seeking novelty

What is there about the dopamine receptor gene that might tilt a person toward liberal views?

The study doesn’t answer that question, but it does say that dopamine is one of many different neurotransmitters found in the nervous system. Genes in our cells carry codes for proteins called dopamine receptors which effectively act as dopamine’s signaling agents.

In particular, the DRD4 has been shown to play a role in a person’s interest in taking risks, seeking novelties and new sensations.

“People who score high on measures of novelty seeking have less tolerance for monotony and constantly seek the new and unusual (to them) in order to alter dopamine levels to affect mood; at the extremes, they are characterized as impulsive, exploratory, fickle, excitable, quick-tempered, and extravagant,” the study says.

On the other hand, it says, “People who score low on this measure tend to be more inclined to follow the rules…to be more reflective, rigid, loyal, stoic, slow tempered, and frugal.”

Well! You can decide for yourself whether those sets of traits square with your notion of what constitutes a liberal or a conservative. I know many a frugal Democrat and quite a few extravagant Republicans too.

No one gene acting alone

But the study’s authors stress that the findings are one faint point in the complicated picture that is the interaction between all of our genes and all of our experiences.

While the study doesn’t speak to the effectiveness of political debates and advertising, the researchers leave plenty of room for political tacticians to sway our votes: “Our findings do not undermine the rich body of literature that has developed regarding the environmental influences that shape political behavior.”

Further, they say we shouldn’t get too hung up on DRD4 or even on novelty-seeking: “Genetic effects take place in complex interaction with other genes and environments, and it is likely the combination of hundreds if not thousands of genes interacting with each other and with external stimuli that influence political attitudes and behavior.”

Their main finding goes beyond this one gene to a better understanding of the role physical heredity plays in political orientation.

“Perhaps the most valuable contribution of this study is not to declare that ‘a gene was found’ for anything, but rather, to provide the first evidence for a possible gene-environment interaction for political ideology,” they said.

Many large-scale studies of political behaviors have ignored the potential for genetic effects.

“In light of these and other findings, political scientists can no longer afford to view ideology as a strictly social construct, perfectly malleable and completely subject to historically changing circumstances,” they say. “Political scientists have a wealth of material from which to form hypotheses about potential gene-environment interactions that influence deeply held political ideas and values.”