Are left and right a feature (or bug) of evolution?
Predisposed: Liberals, Conservatives, and the Biology of Political Differences
by John R. Hibbing, Kevin B. Smith, and John R. Alford
Routledge, 304 pp.
Our Political Nature: The Evolutionary Origins of What Divides Us
by Avi Tuschman
Prometheus Books, 500 pp.
If you want one experiment that perfectly captures what science is learning about the deep-seated differences between liberals and conservatives, you need go no further than BeanFest. It’s a simple learning video game in which the player is presented with a variety of cartoon beans in different shapes and sizes, with different numbers of dots on them. When each new type of bean is presented, the player must choose whether or not to accept it—without knowing, in advance, what will happen. You see, some beans give you points, while others take them away. But you can’t know until you try them.
In a recent experiment by psychologists Russell Fazio and Natalie Shook, a group of self-identified liberals and conservatives played BeanFest. And their strategies of play tended to be quite different. Liberals tried out all sorts of beans. They racked up big point gains as a result, but also big point losses—and they learned a lot about different kinds of beans and what they did. Conservatives, though, tended to play more defensively. They tested out fewer beans. They were risk averse, losing less but also gathering less information.
One reason this is a telling experiment is that it’s very hard to argue that playing BeanFest has anything directly to do with politics. It’s difficult to imagine, for example, that results like these are confounded or contaminated by subtle cues or extraneous factors that push liberals and conservatives to play the game differently. In the experiment, they simply sit down in front of a game—an incredibly simple game—and play. So the ensuing differences in strategy very likely reflect differences in who’s playing.
The BeanFest experiment is just one of dozens summarized in two new additions to the growing science-of-politics book genre: Predisposed: Liberals, Conservatives, and the Biology of Political Differences, by political scientists John R. Hibbing, Kevin B. Smith, and John R. Alford, and Our Political Nature, by evolutionary anthropologist Avi Tuschman. The two books agree almost perfectly on what science is now finding about the psychological, biological, and even genetic differences between those who opt for the political left and those who tilt toward the right. However, what they’re willing to make of these differences, and how far they are willing to run with it, varies greatly.
Hibbing, Smith, and Alford, a team of researchers at the University of Nebraska-Lincoln and Rice University who have published some of the most penetrating research on left-right differences in recent years, provide a lively and amusing tour of the landscape. But they mostly just walk up to and peer at the overriding question of why these apparently systematic left-right differences exist in the first place. Their explanation for the “origin of subspecies,” as they put it, is tentative at best. Tuschman, by contrast, has written a vast and often difficult book that attempts nothing less than a broad evolutionary explanation of the origins of left-right differences across countries and time—and does so by synthesizing such a huge body of anthropological and biological evidence that it’ll almost bury you. Whether the account deserves to be called merely thought-provoking or actually correct, though, will be up for other scholars to evaluate—scholars like Hibbing, Smith, and Alford.
Let’s begin with the large body of shared ground. Surveying the evidence with a fair mind, it is hard to deny that science is revealing a very inconvenient truth about left and right: long before they become members of different parties, liberals and conservatives appear to start out as different people. “Bedrock political orientations just naturally mesh with a broader set of orientations, tastes, and preferences because they are all part of the same biologically rooted inner self,” write Hibbing et al. The research demonstrating this is so diverse, comes from so many fields, and shows so many points of overlap and consistency that you either have to accept that there’s really something going on here or else start spinning a conspiracy theory to explain it all away.
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.
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.
Indeed, here is where perhaps some of the most stunning science-of-politics results arise. Several research groups have shown that compared with liberals, conservatives have a greater focus on negative stimuli or a “negativity bias”: they pay more attention to the alarming, the threatening, and the disgusting in life. In one experiment that captured this, Hibbing and his colleagues showed liberals and conservatives a series of collages, each comprised of a mixture of positive images (cute bunnies, smiling children) and negative ones (wounds, a person eating worms). Test subjects were fitted with eye-tracker devices that measured where they looked, and for how long. The results were stark: conservatives fixed their eyes on the negative images much more rapidly, and dwelled on them much longer, than did the liberals.
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.
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