“Why is everybody wrong except me?”

“These are the times that try men’s souls,” wrote American founder Thomas Paine.

Our own times are more likely to try people’s patience than their souls. We can’t stop shouting at each other. If it’s not about the presidential election, it’s about Israel. If it’s not about Israel, it’s about Ukraine. If it’s not about any of those things, it’s about who gets to use which bathroom.

Many people today are full of passionate intensity, and not only, as William Butler Yeats said, “the worst.” Good people, educated and reasonable, disagree about issues of consequence. In the most tragic cases, argument descends into bitterness. Friendships and family relationships are sundered.

We cannot eliminate disagreement, nor should we try. But if we understand why we disagree, we can minimize the bitterness and become more tolerant of others. 

Consider an example that’s on many people’s minds: Who should be elected president? There are two main choices. Choosing one requires assessing the candidates’ personal character, the merits of their proposed policies, and how accurately they understand the world.

Most of us rely on the campaigns’ carefully fabricated images and sound bites to assess the candidates’ character. We assess their policies based on what we think is desirable, moral, and achievable. We decide the latter mostly through memes and mental images, but also with one eye on what our peer group regards as acceptable opinion.

In the best case, you and a friend disagree. You both respect evidence, respect each other, and sincerely want to discover the truth. You both start with unreliable information, simplified mental pictures, and biases about issues of which you have little or no first-hand knowledge. Your most fundamental beliefs are so much a part of you that you don’t even realize you hold them.

Think about it. Is Hillary Clinton or Donald Trump a good person? A bad person? Given that a small army of propagandists stands between you and them, how sure can you be? Should you support policy X? Making that decision requires you to understand policy X, know the relevant facts, predict reliably about X’s results, and assess its morality when all factors are considered. 

If you have a day job — or even if you don’t — you probably can’t do it. At best, you can learn a few things to support what you believe on instinct. And what you believe on instinct is influenced dramatically by your brain. 

The troubling fact is that human intelligence didn’t evolve to analyze and evaluate complex political or economic issues. It evolved to help us survive and pass on our genes to the next generation. Period.

Biologists call it “the evolutionary legacy principle:” Our brains evolved to cope with prehistoric and pre-technological situations. We use essentially the same cognitive methods to cope with modern situations, and it often works poorly for them.

The biggest single flaw in our cognitive machinery is “us versus them” thinking.

In small primitive tribes, it was helpful to cooperate with “us” and to be hostile or suspicious toward “them” — that is, toward outsiders who weren’t members of our group. Compassion was reserved for other members of our own group, since compassion toward outsiders could get us or other group members killed.

In modern societies, it’s much more difficult and much less useful to decide who is “us” and who is “them.” But our caveman cognitive machinery still putters along as if nothing had changed. If we feel that people who believe X or support candidate Y are “them,” then we tend to disbelieve anything they say. We consider them so despicable or morally unworthy that their feelings and welfare are unimportant. Then we are in danger of becoming cruel and vindictive, as are they.

Our best option is to remember that all of us have flaws and biases, but none of us deserves to be presumed evil and unworthy of consideration.

Let’s listen to each other, pay attention to each other’s concerns, and respect even those with whom we strongly disagree.