5th March 2014
The most rock-solid finding, simply because it has been shown so many times in so many different studies, is that liberals and conservatives have different personalities. Again and again, when they take the widely accepted Big Five personality traits test, liberals tend to score higher on one of the five major dimensions—openness: the desire to explore, to try new things, to meet new people—and conservatives score higher on conscientiousness: the desire for order, structure, and stability. Research samples in many countries, not just the U.S., show as much. And this finding is highly consequential, because as both Hibbing et al. and Tuschman note, people tend to mate and have offspring with those who are similar to them on the openness measure—and therefore, with those who share their deeply rooted political outlook. It’s a process called “assortative mating,” and it will almost certainly exacerbate our current political divide.
As I have always said, there is no such thing as ‘a liberal’ or ‘a conservative’–-‘liberal’ and ‘conservative’ are character traits, not political parties or positions.
But that’s just the beginning of the research on left-right differences. An interlocking and supporting body of evidence can be found in moral psychology, genetics, cognitive neuroscience, and Hibbing’s and Smith’s preferred realm, physiology and cognition. At their Political Physiology Lab at the University of Nebraska-Lincoln, the researchers put liberals and conservatives in a variety of devices that measure responses like skin conductance (the moistening of the sweat glands) and eye gaze patterns when we’re exposed to different types of images. In doing so, Hibbing and his colleagues have been able to detect involuntary physiological response differences between the two groups of political protagonists when they encounter a variety of stimuli. Once again, it’s hard to see how results like these could mean anything other than what they mean: those on the left and right tend to be different people.
Liberals and conservatives, conclude Hibbing et al., “experience and process different worlds.” No wonder, then, that they often cannot agree. These experiments suggest that conservatives actually do live in a world that is more scary and threatening, at least as they perceive it. Trying to argue them out of it is pointless and naive. It’s like trying to argue them out of their skin.
Perhaps the main reason that scientists don’t think these psychological and attentional differences simply reflect learned behaviors—or the influence of cultural assumptions—is the genetic research. As Hibbing et al. explain, the evidence suggests that around 40 percent of the variation in political beliefs is ultimately rooted in DNA. The studies that form the basis for this conclusion use a simple but powerful paradigm: they examine the differences between pairs of monozygotic (“identical”) twins and pairs of dizygotic (“fraternal”) twins when it comes to political views. Again and again, the identical twins, who share 100 percent of their DNA, also share much more of their politics.