This study (Kanai, Feilden, Firth & Rees, in press) is doing the rounds on the blogs. They measured political orientation using a five-point scale of very liberal (1), liberal (2), middle-of-the-road (3), conservative (4), and very conservative (5). Gist: liberals have a bigger anterior-cingulate cortex (ACC) than do conservatives; liberals have a smaller right amydala than conservatives.
There are a bunch of problems interpreting brain volume, e.g., does bigger mean better or does it mean less efficient? Also we know volume can change over time, so finding something in the brain doesn’t imply an initial cause of anything. See more in an earlier post over here.
Interpreting what causes these kinds of correlations is a nightmare. There’s a rather large gap between brain volume and self-reported political orientation. Still, something maybe interesting going on.
First thought about this: hmmm, ACC, that’s to do with dealing with interference which loads on little g. Openness to experience also loads on g. I wonder is this liberal scale tapping into Openness/intelligence?
Here’s a table (from Carney, Jost, Gosling & Potte, 2008) summarising theorized personality correlations.
Lots of high Openness on the liberal side there. Their data also supported the correlation (standardised beta of -.4). Question remains, what causes this? (End of think-aloud for now.)
Carney, D. R., Jost, J. T., Gosling, S. D., & Potter, J. (2008). The Secret Lives of Liberals and Conservatives: Personality Profiles, Interaction Styles, and the Things They Leave Behind, Political Psychology, 29, 807-840.
Kanai, R., Feilden, T., Firth, C., Rees, G. (in press). Political Orientations Are Correlated with Brain Structure in Young Adults. Current Biology.