Political views and opinions run the gamut, from Dick Cheney and Ann Coulter on the right to Bernie Sanders and Rachel Maddow on the left. But why do people hold the particular collection of views that they do? In our new book, Predisposed," we describe research showing that differences in each individual's biological tendencies may help to shape political beliefs.
Social and economic context is clearly relevant to political views but income, race, and upbringing are far from determinative. Many well-to-do individuals, such as Warren Buffett and Teddy Kennedy, embrace left-of-center positions; many African Americans, such as Clarence Thomas and Herman Cain, reside on the right; and an estimated 20 percent of gay males in the U.S. identify with the Republican Party. Parents' positions on important political issues are only weakly predictive of their children's positions. Where people sit socioculturally often does not indicate where they stand politically.
But maybe their biology does. If different people are emotionally aroused by different events and situations, perhaps these varying response patterns are associated with particular political beliefs. For example, several of the issue positions typically associated with the political right, such as support for capital punishment, patriotic displays, stand your ground laws, and sizable defense spending, as well as opposition to heightened immigration and new lifestyles, could be seen as being motivated by a desire for security from threats posed by out-groups, norm violators, pathogens, and the unknown. Given this, we wondered whether individuals who adopt right-of-center positions on these issues might be the very ones who tend to respond more viscerally when shown disgusting, threatening, or otherwise bothersome images.
Suppose we wanted to know the extent to which a person was emotionally aroused by this picture of me eating worms. In the old days, we might have asked participants to tell us whether they found the image to be emotionally arousing but we now know that people often are not the best judges of their own response. Some may mold their answers in order to project a certain image (males are known to understate their response to disgusting stimuli) and some simply are not good at self-reflection.
Physiological measures are a less subjective way of determining the extent to which a given person has experienced emotional arousal. Perhaps the most widely used is skin conductance, a technique that is questionable as a means of identifying whether a single person is telling the truth but universally accepted as a means of measuring activation of the sympathetic nervous system -- the part of human architecture that prepares the body for giving a hug, throwing a punch, wrinkling up a nose, or running away.
My colleagues and I have measured the biological responses of hundreds of randomly selected adults. Anyone conducting these studies is immediately struck by the wide variation in degree of measured arousal. When shown the identical image, some individuals give evidence of a strong biological response, others only a mild response, and still others register no change at all.
Is this variation relevant to political views? In every group tested we found that people with measurably greater biological responses to disgusting and threatening images are significantly more likely to adopt conservative positions on social and defense matters. It is interesting to note that physiological response does not seem relevant to people's preferences on economic issues. In other words, a higher than average response to disgust and threat may characterize social conservatives such as Rick Santorum but not libertarians such as Ron Paul. This makes sense since it is difficult to see why support for, say, lower taxes should correlate with the intensity of physiological response to unsettling images.
Though this pattern of findings turns up repeatedly, it is only a pattern. Not all social conservatives have elevated biological responses and not all people on the political left are electrodermal flatliners. Political beliefs are too rich and nuanced to be determined by any single measure. Still, it would appear biological responses to disgusting and threatening events are an important factor in shaping certain political beliefs. Such a finding is consistent with other research in multiple countries showing progressives and social conservatives differ -- neurologically and otherwise -- in their orientation to the unknown, the unexpected, and the potentially negative.
It might be tempting for liberals to use these findings to claim that there is something biologically wrong with conservatives or for conservatives to gloat that these results confirm their suspicion that liberals are missing something but the truth of the matter is more complex. After all, too little response to a threat could risk harm or even death but too great a response could make it virtually impossible to engage in mutually beneficial trade with other peoples or to experiment with new approaches to longstanding problems.
Rather than twisting these results to suit a particular ideological end, a more appropriate response is to recognize the extent to which the views of our political opponents may not simply be the result of faulty information or a failure to study the issues carefully. Instead, those annoying views are at least partially due to the fact that people on the left and people on the right, probably as a result of a combination of genetics, development, and early life occurrences, experience the world in fundamentally different fashions. The same event that leads to a marked biological response among many social conservatives leaves many of those on the left largely unfazed. Is it any wonder that these different sensations and experiences produce different notions of the best way to organize mass society?