Does our genetic makeup determine the way we vote? Is there something in our DNA that can explain our political opinions?

This notion — referred to in some circles as “biopolitics” — has long been scoffed at by the political science and medical community. Environment, not genes, was thought to be the strongest factor in determining political beliefs and behaviors.

For example, this 2004 American Psychological Association report maintained that environment — not genetics – is the most important component in the development of political and religious views (although it admitted that hereditary transfer can be partly responsible).

But now, political scientists at the University of California, San Diego believe otherwise. They claim to have identified specific genes associated with levels of both voter participation and partisanship.

The molecular biology is a bit over the heads of most people (myself included), but the NYT explains it this way:

According to the researchers, James H. Fowler and Christopher T. Dawes, it works more or less like this: stress causes the release of excess serotonin in the brain, which can kill off neurons if it is not metabolized. People with the right versions of the MAOA gene and 5HTT are better at handling stress because they are better at synthesizing the molecules needed to reabsorb serotonin and break it down. And people who are better at handling stress deal better with the conflicts and strains inherent in forming political opinions and voting.

Similarly, folks with the A2 version of the D2 dopamine receptor gene are more likely to identify as partisans because better dopamine signaling in the brain is related to more social attitudes and promotes attachment to groups like political parties.

There’s long been talk about hereditary transfer of political opinions — after all, there is a strong correlation between the partisan choices of parents and children. Plus, studies of identical and fraternal twins seem to suggest that genes have an impact beyond the acknowledged social and psychological influence that parents have on their children’s political beliefs.

While still controversial, it’s important to note that the aforementioned study only attempts to explain levels of voter participation and levels of partisanship. It does not purport to tackle the deeper question: do genes determine what a person is more likely to believe, or how a person will vote? Is there a gene for conservatives? A different gene for liberals? A variation that causes one to be a libertarian? Did Hitler and Lenin possess certain genes that caused them to champion fascism and communism, respectively?

The answer to all the above questions is, I believe, an emphatic “no.” No matter our hereditary or genetic makeup, the final decision to accept or reject any political view ultimately lies with us. Rational choice theory — the belief that all humans make decisions based on logical evaluations of cost and benefit — lies at the heart of the democratic political tradition. Without the concept of free will, democracies cannot exist. As Rousseau once said:

To renounce liberty is to renounce being a man, to surrender the rights of humanity and even its duties. For him who renounces everything no indemnity is possible. Such a renunciation is incompatible with man’s nature; to remove all liberty from his will is to remove all morality from his acts. Finally, it is an empty and contradictory convention that sets up, on the one side, absolute authority, and, on the other, unlimited obedience.