Is there a gene for liberals?

Is there a gene for liberals? Well, not quite, but scientists say they have found the first evidence that a gene can play a role in shaping an individual's political leanings.

In this case, it appears a variation of a gene known as DRD4, which had previously been linked to risk-taking behavior, also makes people more likely to be liberal. But there's a catch: That's only the case if they had a lot of friends when they were in high school.



Painted tabletop models of the Republican elephant and the Democratic donkey. (Jacqueline Roggenbrodt - AP)

This provocative finding comes from some research by scientists at the University of California, San Diego, and Harvard University. They analyzed data collected from 2,574 adolescents who participated in the National Longitudinal Study of Adolescent Health, which collected information about their genes, friendship networks, and about their political beliefs later in life. They found that people with the "7R" version of the DRD4 gene were more likely to be liberal as adults, but only if they had an active social life when they were adolescents.

"This is the first study to elaborate a specific gene-environment interaction that contributes to ideological self-identification," the researchers wrote in a paper pubished in The Journal of Politics,

The DRD4 gene influences how a brain chemical known as dopamine, which has a variety of affects, including helping control movement, emotional responses, the ability to experience pleasure and pain.

The researchers stressed that 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." It is likely that "the combination of hundreds if not thousands of genes interacting with each other and with external stimuli that influence political attitudes and behavior."

They add: "We do not claim that this evidence proves a causal relationship between DRD4 and political ideology. However, the association is consistent with a causal theory that we develop about the ways genes and environments combine to affect political ideology." Just having the gene does not make a person liberal, nor does "simply having a greater numbr of friends as teenager," they said. The gene also does not cause an individual to have more friends. "Rather it is the crucial interaction of two factors"--having the gene and having many friends--"that is associated with being liberal."

The researchers speculate that having that the gene may make people more interested in seeking out new experiences, including learning about the points of views of their friends, exposing them to a "wider diversity of viewpoints" and leading to their liberalism.

"It is the interaction of the desire for new experience and many different pathways to these experiences that we hypothesize has an impact on political ideology," they wrote.

They hope the research will spur more studies to investigate the interplay between genes and environmental factors in shaping complex human behaviors. Who knows, that could eventually lead to the discovery of a gene that plays a role in creating conservatives.