Born Partisan

Sager sums up a study (pdf):

Contrary to the stories you see floating around every once in a while, no one’s pinned down a biological basis for what makes one a Republican versus a Democrat. In fact, according to a new study, there’s no evidence whatsoever of a Republican or a Democratic “gene,” so to speak. What this new study does find, however, is something a bit more nuanced: evidence that there’s a genetic basis for partisan intensity, as opposed to affiliation. Science might not yet be able to tell you why you’re a Republican or a Democrat, but it might be able to tell you a little bit about why you are so much of one.