That vote you’re about to cast may have been set in motion long ago — going all the way back to your birth and early years, when your genes and your developing brain helped determine whether you leaned conservative or liberal and how strongly you tilted that way.
Even as the presidential candidates canvas the battleground states pleading for last-minute voters to pick between them, some of the latest cutting-edge research suggests that those decisions are influenced by heritable factors that shaped those voters’ political identity long before they were presented the choice between President Obama and Mitt Romney.
“Somewhere between 20 and 50 percent of political behavior in the United States can be explained by genetics,” said James H. Fowler, professor of medical genetics and political science at the University of California at San Diego, who is one of the leading researchers in what has come to be called “genopolitics.”
Mr. Fowler said factors ranging from ideology and partisanship to likelihood of voting are influenced by genes — the only problem is that nobody knows exactly which ones and how they interplay with each other, and that makes predictions impossible.
“There’s a very strong role for genetics, but we cannot yet tell you which genes matter; therefore we cannot tell you which individuals are going to be altered in their predispositions by those genes,” he said.
The latest research suggests genes could control everything from the likelihood that someone turns out to vote down to how intense his or her support is for a political ideology.
Political scientists previously thought political decisions were almost exclusively the product of upbringing and social interaction. But now, four decades after researchers first showed conscious decisions are informed by unconscious attitudes, social scientists are asking whether that affects politics, too.
Crediting genes with political choices is the kind of suggestion that may make voters cringe. Pollsters and political consultants who make their money from guessing what voters want are likely to scoff.
And some analysts question the research altogether, saying it is still too early to draw conclusions.
Marcy Darnovsky, associate executive director at the Center for Genetics and Society in Berkeley, Calif., said the most that could be said is there is “some very complicated combinatorial situation” in which genes, along with a half-dozen other biological and environmental factors, might play a role.
“The steps of logic are so many, and each one of them is a speculative kind of step and a correlation, rather than something you could prove causation about,” she said.
As for controlling someone’s party preference, she said forget about it.
“The simple things of one gene tells you you’re going to vote red or going to vote blue — genes don’t change anywhere near as fast as political ideologies and political parties,” she said.
Indeed, in a review of the latest research, Peter K. Hatemi and Rose McDermott, writing in the October issue of Trends in Genetics, reported that political party identification appears to have little to do with genes. But they found overall ideology does appear to vary with genes, as do attitudes toward economics, race and sex.
Now the search is on for which genes may be at work.