We all know liberals and conservatives are different, broadly speaking. They disagree about immigration, global warming and health care. They consume different brands. The stereotypes tell us liberals eat arugula and drive hatchbacks, while conservatives prefer pork rinds and pickup trucks. These two political classes are so dissimilar that people like to joke they are “wired differently.”

But it turns out that might literally be true. Recent brain science suggests there are measurable differences in how liberal and conservative brains process information—distinctions that could have significant impact on what happens on Election Day.


First, a little background. The brain divides our thought life into two activities: appreciating what we have and desiring what we need. What we have is experienced through the five senses plus our emotions. The brain uses a cocktail of chemicals to orchestrate these experiences that might be called the “Here & Now” brain chemicals, chemicals like oxytocin, which encourages us focus on intimate relationships, and endorphins, which provide feelings of fulfillment and satisfaction.

By contrast, desiring what we don’t have is the domain of a single chemical in the brain: dopamine. It gives us the drive to pursue new things. You know the feeling of that dopamine “buzz” when you find a package on your doorstep and can’t wait to open it, when you think you might have a shot at a promotion, or when you’re out shopping for a new phone.

Dopamine orients us to the future. It helps us think about possibilities; not what is, but what might be. It drives the ambition of the businessman, the creativity of the artist and the speculation of the scientist. In general, the higher the dopamine level in your brain, the greater the urge you feel to find new things, to create new things—to pursue change.

And we know that dopamine activity isn’t purely situational. Some people are born with genes that naturally make their dopamine circuits more active. These people are more likely than others to pursue creative endeavors. Often, they end up as actors, academics, entrepreneurs and writers.

Consider how this might extend to politics. Progressivism, the pursuit of progress, is, by definition, the pursuit of change, of new things. So, we might expect to see progressive ideology in people with more active dopamine circuits. And that’s just what we do find. Researchers from the University of California discovered that people who inherit particularly active dopamine receptor genes are more likely to subscribe to a liberal ideology. (They also tend to get bored easily and seek novelty, and can be impulsive, exploratory, excitable, quick-tempered and extravagant.) It’s no surprise that so many actors, artists, academics and writers tend to be liberal: Dopamine may be driving both their creativity and their politics.

Similarly, people with lower levels of dopamine and higher levels of the “Here & Now” brain chemicals are more likely to take their enjoyment from the appreciation of things they already have. They value tradition. They take more satisfaction from the here and now enjoyment of, say, watching a football game with friends rather than the future-focused promises of a presidential debate. Not surprisingly, genes that code for a less active dopamine system have been linked to people who identify as conservative politically, who tend to prize tradition and see safety in the status quo. A study of 1,771 students in Singapore found that conservative attitudes were more common among those who had a receptor gene that was less reactive to dopamine.

This chemical difference can also help explain why liberals tend to be more politically engaged than conservatives. A 2017 study conducted by the Public Religion Research Institute found that liberals were more likely than conservatives to express political opinions on social media, contact elected officials, donate money to a political campaign, and attend a political rally. If a hundred liberals are marching down the street, it’s most likely a protest. With conservatives, it’s probably a parade.

But even though under ordinary circumstances liberals are more engaged in the political process, liberals don’t always have the enthusiasm edge. Why? Because conservative brains, chemically inclined toward preserving the here and now, are more sensitive to threats that might undermine their current way of life. When a group of volunteers were divided by political affiliation, researchers found that, compared to liberals, conservatives had a stronger physiological reaction to frightening images, such as a spider crawling on a man’s face. Also, when presented with a selection of positive and negative images, conservatives spent more time gazing at the negative images—pictures that represented a threat.

This neuroscience suggests that the current confrontational political climate may be helping the conservative cause. News articles that describe public harassment by activists, for example, trigger threat circuits in the brain and can turn the ordinarily complacent conservative into an enthusiastic partisan. Perhaps conservative leaders know this, which is why they frequently emphasize threats. (See the GOP midterm campaign ads accusing Democrats of encouraging “mob rule.”) In response, liberal leaders might reduce conservatives’ motivation to vote by playing down confrontation, and instead emphasizing the commonality all Americans share.

Of course, it’s important to remember that neuroscientists study large groups of people and report on the averages. So, within each group there are plenty who buck the overall trend—call them dopaminergic conservatives and Here & Now liberals. Most scientific study tells us something about groups, but very little about individuals.

But it’s groups that decide elections, so it’s worth exploring how whether differences in levels of brain chemicals could have consequences in the midterm elections. Biology isn’t destiny, but when you’re playing the odds, it makes sense for both sides to pay attention to the brain.