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“Republican Brains” And “Liberal Genes” Can’t Explain America’s About-Face on Gay Marriage

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How, our grandchildren will ask, did we come to marriage equality in the United States? And we’ll answer, like Hemingway’s Mike Campbell: “Two ways. Gradually, then suddenly.” We can grasp Gradually, the speed we Americans are taught to expect (a government of checks and balances and all that). Suddenly, though, is a bit of a shock to our sense of how the world works. That kind of change is a reminder that people aren’t nearly as consistent and predictable as we’d like to think. This is a problem, not just for common-sense notions of what it means to be conservative or liberal, but for scientific attempts to explain politics in terms of personality, brain function or genetics. Such theories promote the notion that conservative or liberal approaches to life are derived from innate, unchanging traits. If they’re correct, how is it that people can and do change their politics?


The politics-as-personality line is a useful corrective to the rationalist fiction that we consciously choose our political positions by evaluating evidence and reasoning from principles. The new theories grapple with the fact that political behavior isn’t completely under conscious control—that it can emerge from aspects of the self of which we are completely unaware. For example, Jonathan Haidt’s work on differences between liberal, conservative and libertarian orientation found that liberals have consistently different moral intuitions than do conservatives—liberals valuing fairness and reciprocity far more than conservatives, and conservatives conversely valuing purity and sanctity far more than liberals. Since Haidt argues, for good reason, that these intuitions are not subject to choice or control, he’s arguing that people’s politics stem at least in part from the way they are built.

You can read a lot of other versions of this claim in most newsfeeds nowadays. For example, this study found that people who with a stronger involuntary startle reflex were more likely to hold that the Bible is literally true and that the Pentagon budget should increase. On the other hand, people who startled less intensely were more likely to support abortion rights, openness to immigration and marriage equality for gay people.

And this paper reports a difference in the way liberals and conservatives respond to the sight of someone looking off to the side—liberals were more likely to follow the gaze, while conservatives were not nearly as influenced by it. And this one found that conservative positions, especially against immigration and outsider groups, correlated with a more fearful disposition. Then there’s this paper, which found that liberals and conservatives, performing a task that involved risk, did not use the same brain regions to the same extent (conservatives had more activation in the amygdala, which is involved in circuits that get busy in response to threats and surprises, while liberals had more activity in the left insula, which is thought to be involved in self-monitoring). Journalists like me seem to love this stuff. The latter two studies, for example, were trumpeted by Chris Mooney here, where he wrote that they “go straight at the role of genes and the brain in shaping our views, and even our votes.”

The scientists involved in these studies are usually more cautious, noting that they have found correlations, not a causal arrow. They aren’t saying that having a robust startle reflex makes you conservative. But some are willing to argue that there’s an important alignment between politics and one’s fundamental personality. (If they aren’t claiming that, after all, then all they’re left with is a claim that conservatives and liberals are different, which is trivial.)

Which brings us back to marriage equality. If our political positions depend in some important way on the way we’re wired, then what will explain major changes in our political positions? How can it explain an American public that, according to the polls, has gone in seven years from opposing same-sex marriage 70-30 to supporting it by 51-42?

Some political issues pose less of a problem for innate-nature theories because they can be spun in many ways. For example, you can call opposition to fracking “support for our way of life” (purity and sanctity) or “protecting the food chain we all depend upon” (fairness). But same-sex marriage is an emotional issue that touches on people’s sense of their own identity—who we are as a nation—and on their definition of what is moral. If you are one of many people who has “evolved” like President Obama on this issue, then you definitely moved. You can’t frame it so it looks like you were standing still. If politics is rooted in biology, how is that change possible?

A few weeks ago, at this event, I asked Haidt a version of that question. His answer basically predicted the Portman narrative of a few weeks later. What was causing a change of heart about the marriage issue, he said, was personal experience. With fewer gays hiding in the closet over the past few decades, more and more straight Americans came to see the issue in personal terms. Like Senator Rob Portman, whose mind was changed because his son is gay, people came to view the marriage issue not as an abstract question about society but as an problem facing their friend or classmate or work colleague or cousin or child.

In addition to the genuine personal contact made possible by the hard work of gay activists to make the community visible, there was also the pseudo-personal contact of pop culture: Gay people on TV, in movies, in books and magazines, being sympathetic.

I think Haidt is arguing that fellow-feeling was what changed the emotional calculus for conservatives—that once gay men and lesbians are seen as “people like us,” marriage equality is no longer felt as a violation of purity and of authority. It ceases to be the admission of alien “Them” into a tradition that’s sacred to “Us.” Because gay people are part of “Us” too.

Well, maybe. This point of view certainly seems like it could account for gradual changes in social attitudes. You can imagining such change as a kind of positive feedback loop (more openness about gay life leading to more awareness that it’s not alien and weird, leading to more acceptance, leading to more openness, and so on and up).

But there’s still the mystery of sudden change, in the midst of which we sit, astonished. Republican senators are lining up to say they are for marriage equality. Rush Limbaugh calls it “inevitable.” Something is happening now that is not the gradual shifting of reflexes or amygdala activation or gene expression. It doesn’t feel like biology, with its slow and partial squishing and squashing toward change. This feels like a light being switched on (or, if you are on the other side, off). How do we explain that? The science of political behavior, so rich in theories about why people are left or right, needs to pay more attention to why people move left or right.

Follow me on Twitter: @davidberreby

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