Researchers suggest your basic political leanings may be coded in your genes

It is two weeks until election day and the presidential candidates, their campaigns and their supporters have invested huge amounts of time and money to win our votes.

But what ultimately sways us to pick one candidate over another?

Political scientists have focused on the impact of a wide variety of factors that affect voting behaviors, including where we live, and the influence of parents and peers, along with community and religious leaders. More recently, though, there has also been a greater consideration of the idea that our political leanings could be influenced by genetics.

Kara Miller, host of WGBH’s Innovation Hub, has examined recent research that challenges the conventional notion that voting patterns are dictated by environmental factors. Instead, this new research has found, genetics may play a role as well.

“The role that genes seem to play in driving voter behavior has seemed to surprise even scholars,” she said.

It’s somewhat analogous to the way height is dictated by genetics. While genetics dictate how tall you will get, environmental factors, like diet, can strongly modify what your genes are dictating.

The question, though, is how to test this hypothesis. Miller said studies have looked at identical twins, compared to fraternal twins.

“People who are identical twins vote a lot more like each other than people who are fraternal twins,” she said.

Studies have looked at both twins who were separated at birth, and twins who grew up together.

“If you look at genetics, you find that 50 percent of differences in broad ideology can actually be attributed to genetics,” she said. “But it’s complicated. There can’t be a Democrat or a Republican gene, because your genes and your grandparents’ genes and your great-grandparents genes are very similar. And genes also have no way of knowing where (the U.S. or China of sub-Saharan Africa) they are.”

But somehow, they still exert influence.

Rose McDermott co-editor of “Man Is by Nature a Political Animal: Evolution, Biology and Politics,” says genetics can impact the way people rear children, which can then influence their political views.

“In 2012, in the United States, that may look at attitudes toward gay marriage, toward abortion, toward contraception,” she said. “But the underlying issues are really about how we feel about regulating sex and reproduction.”

And markers for that can be found in genetics. Miller says there seem to be three issues that press people’s buttons.

“These have to be issues that are important now, but they were important 500 years ago and they were important 1500 years ago,” she addd.

First, is issues of sex and reproduction, as mentioned before. Other broad issues is how resources are divided, and, lastly, how people deal with “in” groups versus “out” groups.

“That could implications for immigration, but it could also have issues for violence and war,” she said. “You have to think about how do people deal with issues that have affected humans forever.”