When the body perceives a sudden threat, not only is adrenalin released in our blood, but even on the surface of our skin there is a measurable reaction that takes place within 0.05 seconds. And if you can track that, you can get a pretty good idea about how scared someone is. And we can track that. As it turns out, conservatives are more scared than liberals.

Studies like this have becoming increasingly popular as political polarization increases in the US and across the world. In the US, people want to know what makes a Republican different than a Democrat. We’ve learned so much about it that, according to Jonathan Haidt, after a few tests we can not only estimate with reasonable accuracy where someone will come down on political issues, but also what places they want to travel, books they’d like to read, and restaurants they’d enjoy. So the real wonder is not what separates the two parties, but what makes people within those parties so similar—even across seemingly unrelated issues.

There are over three hundred million people in America, and yet we break down into two distinct parties. Thousands of bills before congress, two parties. Of course many feel that their personal beliefs do not fit perfectly into their party, and this is likely true, this year more than ever. But what makes a gun owner so much more likely to vote against abortion? And what makes people who favor Obamacare so much less likely to favor military spending?

So while your party might not be a perfect fit, consider this: Do you have a pretty good idea about where your friends will come down on different issue, even before asking? Once we know someone’s position on a few issues we have a pretty good idea about the others. I know with reasonable accuracy how John will feel about Brixit. I know Jessica’s view on abortion. And I know Derek’s candidate of choice. I know all this without having ever talking to them about it. Of course, sometimes I’m wrong, but that’s more of an exception. I might not know all their mental justifications, but I have a pretty good idea where they’ll end up.

So how have parties become so internally homogenous?

According to one theory, what makes one man a conservative and another woman a liberal is how open they are to change. The conservative is a slightly more cautious individual who perceives threat relatively easily, while a liberal is less scared of negative stimuli and more open to change. A liberal votes liberally because those platforms are more appealing to someone of their biological temperament.

But wait. Let’s say I’m open to change, how do I know what would be most appealing?

Let’s take the issue of climate “change.” Sounds pretty appealing, right? So why aren’t the conservatives trying to enact policies to preserve biological homeostasis and the liberals critiquing them for always trying to maintain the status quo?

To try and decide which policies would be most appealing to open-to-change people is a bit like deciding the best value refrigerator by reading through the ads. The policies have already been inscribed with rhetoric, and the message is: if you’re this kind of person, vote this way. And so we do.

To understand this point, consider my friend Ryan Dart. This is a man who works from his garage. He designs furniture. His best stuff is cut by a computerized router and pieced together by hand. He calls it digital organic. When it’s finished, the tables and chairs look like they’re made from honeycomb. It’s gorgeous.

But at first he couldn’t sell any of it. He lowered his prices and still, nothing. And then he raised his prices and changed the tagline of his studio from “modern furniture” to “functional art.” And that’s when it took off. The furniture itself was only part of the equation. Ryan also had to change the meaning of his furniture. What he sold was more than wood and metal. He inscribed his furniture with a message: if you want modern furniture you can get that at target, but if you want functional art then you should go to Ryan Dart. And people started buying because owning Ryan Dart furniture meant something about them.

The same is true of policy. People tend to form opinions based on what those opinions say about them. Opinions are not so much about the policies as much as the messages that have been inscribed within those policies. If we were to strip each issue of its accompanying rhetoric (as impossible as this is), take away the ads as it were, and simply compare the apparent pros and cons of various policies, would we get the same clear party lines separating people?

Let’s return to the issue of climate change as an example. Here’s a thought experiment: what if we could take a mixed group of people who had never heard of climate change. Let’s say half the group is naturally conservative and half liberal. Then we take the group through the evidence in order to answer a list of questions. For example: Does it exist? Is it a major problem? What are possible solutions? What’s the best solution? What are the economic costs associated with various solutions? Do costs outweigh the benefits? How do we synchronize our efforts with other countries? How do we enforce regulation? Etc. Once everyone in the group has answered all these questions, would we have two consistent groups anymore? I doubt it.

For each issue there is room for hundreds of positions, how would we possibly come down to two cohesive groups? Now what would happen if we did that same experiment with all 5,000 of the bills proposed before congress each year? To get consistent outcomes is as improbable as flipping a coin 5,000 times and getting the same pattern as the person next to you. That’s practically zero. And by practically, I mean when I put the numbers in my calculator it comes out as 1/infinity. The odds of three hundred million people doing the same toss and developing two consistent patterns, yeah, you get the point.

It’s hard to imagine that we would ever come out of any of these issues feeling we generally agree, with anyone. But we do, all the time. In the senate, senators vote along party lines 91.7% of the time (according to my own calculations).

So how do we agree so much?

The Septuigent is the Greek translation of the Hebrew Bible. When it was translated it is said that King Ptolemy gathered 72 elders into separate rooms and had each translate the text individually. The miracle is that each translation was the exact same. How was it possible for 72 people to make the same translation choice 622,771 times? The answer is simple: either it was a miracle or they didn’t. But the story of the translation helped to preserve the authority of the text and the identity of the people. And that’s the key, the miracle was all about preserving the identity of the people.

That is the case in politics as well. We agree so much because we seldom deal with the issues themselves. We aren’t translating individual words. No one could read the science, scrutinize the methodology, explore critiques, and research solutions for all the issues. And even if we could, we could never get below the giant industry that funds research, generates opinions, and promotes solutions. Instead, we are the consumers at the end of the whole process. We do the same things in choosing what political platforms to “buy” as we do in picking what clothing to purchase.

Consider the recent decision that millions of men have seemingly individually made to grow a beard this last year. Is this another amazing coincidence? Of course no one thinks of it as a coincidence. Coincidences like that don’t happen. The fondness for beards has been the result of shifting identities and signifiers, and while we never fully understand those shifts, we all know they are happening all around us. And yet it’s real to us. Our fondness for beards has actually increased, our own opinions have changed to be in harmony with the people around us. That’s easy to admit. But we don’t want to believe that our political opinions are as malleable as fashion.

So how do we choose what policy we like best? I think, as surprising as it may sound, we don’t. Instead we come to it. We come to it in the same way we develop a hairstyle. We don’t get to choose which haircuts are in style, but we do choose how we want to be perceived. And that’s the haircut we choose. If our haircut was something we chose independently of each other, it would be pretty hard to explain the random influx of overcuts.

Liberalism and conservatism are two popular styles and all the policies, like a lot of hair product, is catered around them. And most of us choose policies, not because it’s the best product—we seldom have time to really comprehend the ingredients—but because of what it says about us, and how it’s sold to us.

An interesting study showed that one in five Americans somehow managed to inherit what they incorrectly believed their parents’ political leanings to be. This is interesting because it suggests that people don’t simply inherit political persuasions in the way they inherit biological traits. It also means people don’t simply grow up in a certain environment which dictates how they will end up politically. Rather, it’s an issue of perception. Children who misperceive their parents to be liberal, often end up liberal. It’s not the actual product that convinces us to buy it, but how we perceive it.

Today is election day. For the past year the candidates have talked about issues and proposals with the goal of getting their team to the voting booths. And it’s hard to believe that how we vote might not be about the facts, issues, and insights, but our own identities. However, the very process of voting itself is all about identity. There has never been a presidential vote in the USA decided by one vote, no matter how you measure that vote. So there is no chance your vote will make a difference. But we still vote, and we wear stickers that tell everyone we voted because voting is how we participate, it’s how we’re a part of the community. So again, voting is about us more than it is about the issues.

So before you vote this year, take a look in the mirror. What’s your hairstyle? Is it really so hard to believe that your politics might not be so different? When you get a new haircut, notice how everyone says you look nice. Because to dislike someone’s haircut is personal. And that’s why it’s hard to talk about politics. Because if you disagree with someone, it’s not just about the ideas, it’s about them. If you argue, you’re not just taking down a position, you’re taking down a person. But what if we could all admit that we don’t know half as much as we put on—that we probably only like beards because they’re popular and we want to stay with the times.