The physiology and psychology of voting

In case you haven’t noticed, election season is upon us! Ok, it has been upon us for almost two years, but never mind that. Pollsters are busy trying to determine why people might be voting for one candidate or another, with special attention being paid to the so-called undecided voters, on whose last-minute whim the fate of the nation -- and the world -- seems to hinge.

Two recent studies, however, provide much food for thought about why people vote one way or the other, and about the reasons they give to themselves and others. A paper by Douglas Oxley and collaborators in Science (19 September) investigated the effect of physiological reactions to a perceived threat on people’s political opinions. Their findings were startling, to say the least. Oxley and colleagues discovered that people who react physiologically (as measured by changes in their skin conductance) to sudden noises or to threatening images are much more likely to support conservative issues like gun control, the war in Iraq, restrictions in immigration and so forth.

Indeed, the magnitude of the response was astounding. The researchers used a multiple regression analysis to compare the effects of change in skin conductance levels in response to threatening images, gender, age, education, and income on support for socially “protective” policies such as the ones listed above. The only two statistically significant effects were those of education (less education translated into more support for conservative policies) and skin conductance. That in itself means that -- within the confines of this study -- physiology trumps gender, age and income, traditionally considered highly relevant causal factors in politics by social scientists. Moreover, the regression coefficient associated with skin conductance was more than 56 times that of education! Similar results were obtained when skin conductance was measured in reaction to startling noises, though in that case the corresponding regression coefficient was of the same magnitude as the one for education. Finally, when skin conductance was measured in response to non-threatening images, the only variable with a significant effect was education. Wow.

The news for political scientists doesn't get any better after one reads the second study, by S. Galdi and collaborators, also published in Science earlier in the summer (22 August). Galdi and colleagues were interested in the effect of what Science commentators Wilson and Bar-Anan call “the unseen mind,” that is the unconscious apparatus that our mind uses for rapid decision making. The results strongly indicated that whatever reasons people give for their choices have little if anything to do with the real reasons they make their choices. For instance, subjects were given photos of two women and asked to pick which one they preferred. After a while, the subjects were shown the picture they selected and asked to provide the reasons for the choice. Here is the kicker: through sleight of hand, the experimenters sometimes provided the respondents with the wrong picture, the one of the woman they said they did not like. Surprisingly, people articulated convincing reasons for their stated choices, regardless of whether they corresponded or not with their original ones! In other words, once confronted with a given choice, even the one they did not make, subjects were perfectly capable of providing reasons for that choice, with seemingly no hint of conscious fabrication. They were simply able to quickly convince themselves that that was in fact their choice, and to equally quickly provide the researchers with the rationale for it. So much for the value of exit polls.

This sort of research keeps raising questions about Aristotle’s assumption that humans are “the rational animal,” an assumption on which philosophical discourse, science itself, and public education are all based. It increasingly looks like we are more like “the rationalizing animal,” with serious consequences for how we interact with each other. Even so, I’m inclined not to be too pessimistic, though, since learning more about how the human mind really works -- as opposed to the way we would like it to work -- is surely the only way to discern effective from fruitless approaches to engage that mind in productive discourse. Just beware of loud noises, threatening images, and investigators who surreptitiously switch the pictures of women you like with those you don’t.