Once again, Election Day is just around the corner, and if you haven't already voted with an absentee ballot, you've probably decided whether or not you'll be standing in line at the polls. If it makes you feel any better, you may not have a choice. Your decision could be genetic.

James Fowler, a political scientist at UC San Diego, is leading a team studying and comparing the voting histories of genetically identical twins and fraternal twins who share only about half of their genes. The theory is that if the decision to vote has genetic roots, identical twins should have more similar voting histories than the fraternal twins.

The study was published in Scientific American and reported in The Wall Street Journal. Fowler's analysis of one database indicated that 60 percent of the differences in the voting histories were the result of genetic factors and not environmental or other influences.

A review of Fowler's data by Robert Plomin, a behavioral geneticist at King's College London, said he thought it was more like 40 percent, a margin still wide enough to indicate a hereditary trait. It seems a little far-fetched to me that some of us could be carrying a "social responsibility" gene that predisposes us to vote, as opposed to a candidate who inspires us to vote. Still, it's an interesting concept.

I can already imagine the scene on "CSI: Miami."

"Can you identify the murderer?" says the detective.

"No, but using his DNA, I can tell you he's a voter."

I think that if there was really anything to this whole genetic disposition toward voting, especially among twins, the politicians would have figured it out a long time ago. What could be better than luring twins to your campaign? Sort of a "double your pleasure, double your funds" approach to both fundraising and balloting.

Far be it from me to argue with a behavioral geneticist, assuming I could actually find one, but voting is one of those things that seem to me to be more of a learned behavior, culturally defined, than it is an inherited one. In fact, the U.S. Census Bureau report on the 2004 presidential election is silent on the role of genetics in election results, but it does note that most voters in the 2004 election were women. Among registered voters, 65 percent of women voted compared with 62 percent of men. And older Americans voted at a higher rate than younger voters.

The voter rate for citizens 55 and older was 72 percent while those in the 18- to 24-year-old range came in at 47 percent. To me, this may be the most telling statistic in the whole argument.

I fall between the two age groups (barely), but I believe older generations of Americans had the right to vote instilled in them as a privilege, and one not to be taken lightly. We weren't born with a predisposition to vote. We were raised to believe it was a fundamental responsibility and honor as an American.

I'm proud that both of my children are regular voters, and I believe they got that from my wife and me, but not genetically. I like to believe that my children are mannered, educated and good citizens because we were good parents, not just conduits for inherited traits.

So, if you choose to vote, I say it's not your genes, it's your choice and your duty.

— Contact Star columnist Bill Nash at bnash805@aol.com.