The Republican Brain (21 page)

Even if liberals have more gray matter in the ACC, or if this brain region is more active in them, that doesn't tell us whether being a liberal leads to more growth and development of the ACC, or whether having a bigger or more active ACC makes one a liberal to begin with—or both. The same question goes for conservatives and the amygdala. Meanwhile, even if these brain regions do shape our politics—which seems likely—it's doubtful they will turn out to be the only ones.

Nevertheless, right now the neuroscience evidence is lining up behind the psychology evidence in a way that makes a fair amount of sense. Remember, most of all, the evidence from the last chapter, showing that liberals who are made to feel fear behave more like conservatives—or, more like authoritarians. It is not exactly a radical stretch to suggest that the amygdala has something to do with this effect.

Everybody has the capacity to feel fear. But recent research suggests those who have greater fear “dispositions”—a trait that's linked to much more distrust of outsiders, including immigrants and people of different races—tend to be politically conservative. So what if it's the case that conservatives and authoritarians have a more active amydala in general, and go through life more sensitive to fear and threat? And what if, by contrast, liberals are more prone to “switch on” and “switch off” on this dimension, and only behave like conservative-authoritarians when they're made afraid as they were after 9/11—when a whole breed of “liberal hawks” emerged who wanted to attack Iraq?

Neither group, in this interpretation, would feel there was anything
wrong
with their lives or experiences. Yet for each group, life would be lived just a little bit differently, on average—and one consequence of those differences might be our political divisions.

If that's true, then Irving Kristol's famous remark that a neoconservative is just “a liberal who has been mugged by reality” would take on quite a new meaning.

Even assuming that this seemingly “obvious” interpretation of the neuropolitics research is correct, it tells us nothing about what causes our brains to differ in ways that correspond to our politics.

As I've said already, your brain could cause you to have a particular political outlook, or your political outlook could cause you to have a particular brain. Or both. And indeed, “both” is very likely the reality of the situation.

We know the brain is highly plastic. So we know that our life experiences, including our political experiences, change it. That side of things is pretty well accounted for, even if we don't always know which regions respond to which experiences, with which changes.

The thing is, we also know that political views are partly inherited, and explained by genetics. Not fully explained, of course, but the influence of genes on our politics is surprisingly powerful. There's a persistent body of research suggesting that 40 percent or more of the variability in our political outlooks is ultimately attributable to genetic influences. And this evidence is hard to refute, because it is based on a classic research model for detecting the genetic heritability of traits: twin studies.

So-called “identical” twins share the same DNA, and grow up in the same family environment. Meanwhile, fraternal twins also grow up in the same environment but only share half of their DNA. This leads to the time-honored twin study design. Gather large numbers of identical and fraternal twin pairs, and measure how much members of the two different kinds of pairs diverge on some trait, and you'll be measuring how strongly genes control it.

Inevitably, for any heritable trait—height, personality, and so on—identical twins have more in common than the fraternal twins. What's amazing is that politics is such a trait. Indeed, as previously noted, twin studies suggest that genes explain 40 percent or more of the variability in the overall political attitudes we adopt. At the same time, genes seem to account for a much smaller percentage of the variability in one's political party affiliation, but that's not necessarily so surprising. Party affiliations shift with generations and time; left-right orientations, not as quickly.

Indeed, twin studies have also been used to show that genes explain a substantial percentage of the variability in personal religiosity or spirituality, church attendance, and especially conservative religiosity or being “born again.” But they don't predict the specific religion we'll adopt. Our parents control that: They bring us up “Baptist,” and they bring us up “Republican.”

As with the political neuroscience research, it is very easy to misinterpret the findings of political genetics. Nobody is saying, for instance, that there is an actual “conservative gene” or a “liberal gene,” any more than that there is a “God gene.” Rather, the idea seems to be that genes create basic dispositions or tendencies that in turn produce personalities—which, in turn, predispose us to political outlooks. It's also possible that the same baseline set of genes may influence our personalities and our political outlooks separately, and these then wind up being aligned because both are influenced by the same genetic factors—kind of like two separate limbs of a puppet being pulled by the same puppeteer. In this view, Openness may not cause liberalism; rather, they would both be influenced by the same set of genes.

But either way, something is being passed on to us that winds up getting expressed as ideology. “It's almost impossible to deny that there are these consistent pedigrees passed down through families,” says Peter Hatemi, a political scientist and microbiologist at Penn State University who has been at the center of research on the relationship between genetics and politics—a growing field. “The basic state of who we are, that's inherited.”

It's important to understand what a statement like this means—and doesn't mean. Popular misconceptions notwithstanding, it is wrong to think of human traits as being either caused by genes or caused by the environment (upbringing, life experiences, and so on). Take height, for instance. Yes, it has a genetic basis and is strongly inherited. But if you're malnourished, you'll stunt your height no matter what kind of basketball star your genes might otherwise have been able to produce. “Nothing is all genes, or all environment,” Hatemi explains.

In fact, the very attempt to pit genes and environment in opposition to one another is nowadays a passé notion in science. We know that genes strongly influence us; we also know that environmental influences, aka our “experiences,” change us and change our brains. And get this: Environmental influences also change our
genes
, or at least how they are expressed by our bodies, via the production of proteins in individual cells (including individual brain cells). “Epigenetics” is the study of the many factors that modify the way our genes are expressed, even without any changes to the basic DNA code. It's more about genes “switching off” and “switching on”—in different cells, in different phases of life, and even in response to our own choices and behaviors.

When it comes to political genetics, for instance, some research suggests that while we're living at home with our parents and growing up, the family environment has a lot of influence on our ideologies—especially during our teenage years. But once we leave the nest, perhaps to attend college, it is suggested that
then
our genes kick in and start shaping us.

No wonder this area is complicated, and promises to fuel generations of ever-more-sophisticated research.

If genes are influencing our political views, you can rest assured their influence is not going to be manifested through our elbows. It'll be manifested through our brains. One obvious area to examine will be how our genes influence neurotransmitters like dopamine, which carry chemical messages between our brain cells.

The question then becomes, which genes are involved, and what do they do?

It is very unlikely that we will find a few political genes that explain everything, or even that have very large effects. Rather, with a complicated social behavior like one's political views, there are probably thousands of regions of the human genome involved, and these are affecting us in different ways—ways that are often triggered by the environment, and that vary over a lifetime.

At this very moment, the search for them is on. Scientists like Hatemi are conducting genome-wide studies to try to find what are called
polymorphisms
or
markers
—areas where the human genome varies from individual to individual—that are related to politics. This requires vast studies, with thousands of participants who get their genomes scanned and answer political questionnaires. Eventually, the hope is that markers will be identified that are statistically linked to political opinions—but it will probably turn out to be thousands of them, and it will be very hard to find all of them.

So far, there is at least one “liberal gene” claim. University of California-San Diego political scientist James Fowler and his colleagues have highlighted a gene called DRD4, which seems to be involved in novelty seeking. Technically, the gene codes for a protein receptor that is activated by dopamine, a chemical messenger in the brain. The idea seems to be that a particular variant of this gene (if you have it) plays a role in the trait Openness to Experience, and thus, in liberalism. But here again, there's a gene-environment interaction: The gene's contribution to Openness appears to depend on your social life and how many friends you had growing up.

That's certainly intriguing, but again, we shouldn't place too much weight on any one gene to explain why people vary in their political outlooks. Consider once again that steadfast analogy—the role of genes in height. Whereas genes appear to explain 40 percent or more of the variability in our ideologies, they explain 80 percent of the variability in height. However, scientists digging through the genome to try to find the “height” regions, over years and years, have only found about 20 percent of the specific DNA strips involved, according to Hatemi. That means sixty percent of the genetic regions involved in height remain unidentified, although we know they're in the genome . . . somewhere.

Right now, Hatemi continues, less than one percent of politics can be similarly explained. He expects that to gradually change as researchers continue to comb through genomes—and then, the real fun begins. Once regions are identified that are involved in politics, the question will become how their activity affects us: Not just at one point in time, but
over
a lifetime, in interaction with the environment.

For many scientists, this itself portends a lifetime of exceedingly complicated research. But why do it?

The thrill is to be part of a dramatic new merger of political science, psychology, and biology that ultimately promises to uncover a “science of human nature”—sure to yield fruit, but not necessarily to produce full clarity any time soon. For now, you have to be patient, live in the uncertainty, and thrill in the search.

Any guesses about what personality types will want to be working in this area, or how they are likely to vote?

On this account of the origins of our politics, it would appear not only that political dispositions travel in families, but so do personalities—and these traits would presumably emerge when we're quite young.

And, there's suggestive evidence supporting this notion as well.

It is difficult and expensive to conduct a so-called longitudinal study that looks at the personalities and behaviors of young children, and then follows them until they are grown-ups to see how they identify politically. That kind of lifelong commitment to a scientific study is rare, and even heroic.

But in at least one case, it has been done. And the research, conducted at the University of California at Berkeley beginning in 1969, suggests that the children's politics had already been set in motion at an early age. Note also that because this study was longitudinal, it is hard to imagine how the researchers could bias it: They didn't know what was going to happen to the kids they observed. They couldn't superimpose knowledge they would only gain later on what they saw as they watched three-year-olds play.