About Rationally Speaking

Rationally Speaking is a blog maintained by Prof. Massimo Pigliucci, a philosopher at the City University of New York. The blog reflects the Enlightenment figure Marquis de Condorcet's idea of what a public intellectual (yes, we know, that's such a bad word) ought to be: someone who devotes himself to "the tracking down of prejudices in the hiding places where priests, the schools, the government, and all long-established institutions had gathered and protected them." You're welcome. Please notice that the contents of this blog can be reprinted under the standard Creative Commons license.

Tuesday, April 04, 2006

The partisan brain

We all know that political discussions are emotional, just witness some of the comments people leave on this blog whenever I write about politics or religion, rather than, say, science or philosophy. A recent study by Drew Western at Emory University showed how this looks from inside the brain, and the results highlight in a spectacular fashion how difficult it is to engage in rational discourse.

Western conducted his study during the 2004 Presidential campaign. He selected a group of committed Republicans and Democrats, and presented them with a series of statements by candidates Bush and Kerry – all while monitoring their brains inside an MRI machine. The statements in question came in pairs, with the second pair contradicting the first one, simulating a classic case of “flip-flopping.”

Not surprisingly, both Democrats and Republicans judged the opposing candidate very harshly for being inconsistent, but were lenient, or not bothered at all, by the inconsistencies of their own candidate. What was interesting, however, emerged from the brain scans: there was very high activity in regions of the brain regulating negative emotions (when reacting to the opposing candidate) and stimulating forgiveness (when considering the favorite man’s position), but very little going on in those regions usually in charge of rational reasoning!

Of course, this doesn’t mean that political partisans cannot think rationally, or even change their mind, from time to time. But it does clearly show that emotional reactions are the first ones to emerge, overriding the rational circuits. That is why it takes training in critical thinking, and quite a bit of self-restrain, to be able to take a deep breadth, count until ten, and force oneself to really look at whatever claim or situation by using our cortex’s reasoning ability. Back to the brain gym for some much needed exercise, everybody!


  1. M-
    For another take on when the brain overrides rational thinking, you may be interested in the NY Times article "Living on Impulse" (in the Health section online), especially towards the end of the article where the author discusses the danger of "people who trust their first impressions implicitly and absolutely."

  2. Aaron Blaisdell here, author of the Science paper you discussed. Thanks for the pleasant blog report of our results. You didn't get the details of training exactly right (i.e., the noise (tone, actually) was never paired directly with food - which could lead to a direct association between them), but you did relay the gist quite well. I agree with your suggestion that much of human reasoning is going on below the surface of awareness. The irony is that it is the research in animal psychology that leads us to the idea that much of human reasoning and rationality is "mindless" (by which I mean nonconscious) as well.

  3. Aaron,

    thanks for dropping by and for providing the correction. It's a very nice piece of work, congratulations.

  4. We are all guilty of letting our emotion get in the way of reason. Especially on the political front. I just as much as any. It is a shame that to get into politics you must align yourself with either the R or D party. This only festers exactly what what your blog is about. Its too bad that all politicians are not independant. Perhaps that could remove some of the emotion out of decision making. But we know how far the independent usually makes it in politics.


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