Ever wondered why you have a hankering to drive a Prius and drink lattes? Or why you read the Guardian and scrupulously put it in the recycling? There might be a gene for that – with a little help from your friends.
Researchers at the University of California and Harvard University have identified a specific gene variant that they say predisposes those carrying it to liberal political ideology – with the findings quickly seized on by the US media as uncovering "the liberal gene".
Simply having the gene – a variant of a dopamine receptor known as DRD4, linked to novelty-seeking – is not enough by itself to make someone a liberal, according to the article in the latest issue of the Journal of Politics, published by Cambridge University Press. The study found that adults with the gene were more liberal depending on how wide their circle of friends was while they were growing up.
"It is the crucial interaction of two factors – the genetic predisposition and the environmental condition of having many friends in adolescence – that is associated with being more liberal," the researchers state. They found that the correlation held true independently of gender, age or ethnic and cultural background.
According to the study: "Ten friends can move a person with two copies of [the gene variant] 7R allele almost halfway from being a conservative to moderate or from being moderate to liberal."
The research, led by James Fowler of the University of California's San Diego campus, suggested that those with the novelty-seeking gene variant would be more interested in learning about their friends' views, exposing them to a wider variety of lifestyles and beliefs and making them more liberal as a result.
"These findings suggest that political affiliation is not based solely on the kind of social environment people experience," said Fowler, a professor of political science and medical genetics best known for his work on social networks with Nicholas Christakis of Harvard, who worked on this study.
The authors, however, say their findings should be "treated cautiously" and that more research is needed before hailing a liberal gene. "The expectation in genetics is that only repeated efforts to replicate associations on independent samples by several research teams will verify initial findings like these," they wrote. "Perhaps 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."
By matching genetic data with the friendships and social circles of those surveyed, the researchers could show that people with the variant of the gene were more likely to be liberal as adults if they also had an active social life during their teenage years.
"It is our hope that more scholars will begin to explore the potential interaction of biology and environment," Fowler said.
By Richard Adams, The Guardian