A recent report in Nature Neuroscience has gotten a lot of press. The headlines proclaim that “left-wing” brains are different from “right wing” brains. Are our brains literally hard-wired to be conservative or liberal? The article in the L.A. Times sure seems to suggest it:
Sulloway said the results could explain why President Bush demonstrated a single-minded commitment to the Iraq war and why some people perceived Sen. John F. Kerry, the liberal Massachusetts Democrat who opposed Bush in the 2004 presidential race, as a “flip-flopper” for changing his mind about the conflict.
Really? Could one study of 43 college students actually tell us all that? Let’s take a look at what the researchers, led by David Amodio, actually did find. Participants first took a survey in which one of the questions asked them to rate their political orientation on a scale ranging from “extremely liberal” to “extremely conservative.”
Next they were attached to an electroencephalogram while they completed a quick go/no go task. The task is mind-numbingly simple, but it can be extremely difficult in practice. I’ve created a little movie (QuickTime required) so you can try it out. When you watch the movie, tap your finger on your desk every time you see the letter “W”, and don’t tap for any other letter.
Not as easy as it looks, is it? Now on to what the researchers found:
The W is shown 80 percent of the time, and the M is shown the rest of the time. After a while, it becomes quite difficult to resist tapping when you see the M. The researchers found a difference in accuracy between the viewers who said they were liberal and those who said they were conservative (viewers typed their responses on a keyboard instead of tapping on a desk). Liberalism correlated significantly (r = .30) with accuracy on the task. (Yes, the researchers controlled for the letters in the study — liberals aren’t only better at resisting when the letter is “W”.)
They also found a difference in brain activity in two parts of the brain (actually this was measured in electromagnetic potential at the surface of the head, and the researchers extrapolated to find the location of the activity). Political orientation was correlated significantly with the strength of brain activity during the key no-go portion of the task (r = .41). The researchers calculated that the increased activity was occurring in the anterior cingulate cortex, responsible for conflict monitoring.
In other words, liberals are more likely than conservatives to have a strong response in the area of the brain used to inhibit responses at the time when they are supposed to inhibit response. So is this why Bush invaded Iraq and Kerry flip-flopped? Actually, Frank Sulloway, who made that claim, wasn’t involved in the project. When the L.A. Times reporter finally interviewed Amodio, his response was much more guarded. According to the article, he “cautioned that the study looked at a narrow range of human behavior and that it would be a mistake to conclude that one political orientation was better.”
The study results are actually quite modest — the researchers claim to be the first to find a relationship between political differences and “a basic neuro-cognitive mechanism for self-regulation.” However, these results are supported by a wide range of behavioral data which does support the idea that conservatives are less willing to accept complex arguments or shades of meaning compared to liberals.
Does this mean that liberals are “hard wired” to be different from conservatives? This data alone certainly doesn’t support that claim. After all, the go/no go task is a learned activity. The reason that it’s hard to inhibit tapping when the “M” appears is that you’ve learned to tap when you see a letter. You could also learn to tap only when you see an M, and you might be able to learn to be better at this task. Could you learn to be liberal (or conservative)? This study doesn’t answer that question, but my suspicion is you could. After all, what’s considered liberal in the U.S. is considered conservative in many places. In other places, a U.S. conservative would be considered a flaming liberal.
Amodio, D.M., Jost, J.T., Master, S.L., & Yee, C.M. (2007, Sept. 9). Neurocognitive correlates of liberalism and conservatism. Nature Neuroscience. DOI:10.1038/nn1979.