Last summer I was at a moral psychology conference in Chile, listening to speaker after speaker discuss research into how people think about sexuality, crime, taxation, and other politically and socially fraught issues. The consensus was that human moral reasoning is a mess—irrational, contradictory, and incoherent.

And how could it be otherwise? The evolutionary psychologists in the room argued that our propensity to reason about right and wrong arises through social adaptations calibrated to enhance our survival and reproduction, not to arrive at consistent or objective truth. And according to the social psychologists, we are continually swayed by irrelevant factors, by gut feelings and unconscious motivations. As the primatologist Frans de Waal once put it, summing up the psychological consensus: “We celebrate rationality, but when push comes to shove we assign it little weight.”

I think that this is mistaken. Yes, our moral capacities are far from perfect. But—as I’ve argued elsewhere, including in my forthcoming book on empathy—we are often capable of objective moral reasoning. And so we can arrive at novel, sometimes uncomfortable, moral positions, as when men appreciate the wrongness of sexism or when people who really like the taste of meat decide that it’s better to go without.

In fact, the strong view of some evolutionary theorists—that real moral reasoning is impossible—isn’t even coherent. As an example, take Robert Kurzban’s excellent book, “Why everyone (else) is a hypocrite,” which argues that there is no unified self and that consciousness is largely superfluous—moral reasoning instead arises from a cluster of mental systems shaped by natural selection, leading to often inconsistent assessments of the behavior of others.

But then, at the very end of his book, Kurzban complains about what a mess this all is—“My own view is that while hypocrisy is the natural state of the human mind, it makes for bad policy.” He is particularly concerned by how unjust it is when people restrict the liberty of others without cause, as when our sexual morality makes us freak out at the behavior of consenting adults. He suggests that a better understanding of how the internal dynamics of the mind works, “gives us the opportunity to appreciate the conflict, and to change the balance of power.”

This all makes good sense to me. But the idea that we can step back and assess and override our feelings assumes that we can transcend this cluster of evolved, stupid neural systems. Similarly, when one speaker in Chile described people’s crazy intuitions about certain market interactions, his audience roared with laughter, so certainly we were capable of thinking differently.

One sees this a lot—a psychologist (or a philosopher, or a neuroscientist) presents a mental quirk or limitation of humans and then draws a pessimistic conclusion about human nature in general, forgetting for the moment that their argument presupposes that we are also savvy enough to appreciate when things go awry. The same point applies in other domains, where certain biases lead people to make errors, such as over-estimating the likelihood of rare but salient events, like shark attacks. These are cool findings but we shouldn’t forget that the same creatures who make these mistakes are also smart enough to identify and laugh at them.

But what about a milder version of the moral irrationality position? There’s nothing incoherent about arguing that much of the time we are irrational, or that some people are more irrational than others. Indeed, both claims are almost certainly true. What’s more controversial, but still possible, is that certain types of people are less rational.

Psychologists and other social scientists used to argue for the irrationality of women and minorities, particularly of African descent—arguments that are now understood to be false.  Now they make this claim about political conservatives. One popular theory is that conservatives are highly prone to “system justification,” which leads them to endorse, as John Jost and his colleagues put it “a fairly wide range of rationalizations of current social, economic, and political institutions and arrangements.” Note the word “rationalizations,” as opposed to actual arguments or reasons. Conservative policies—such as opposition to affirmative action and income redistribution—are seen as the products of cognitive biases.

One response to this has been raised by José Duarte and his colleagues, who worry that political psychologists are an ideologically homogenous bunch—the number of prominent scholars in this area who self-identify as conservative could fit conformably into a Prius. When members of the preeminent Society for Social and Personality Psychology (SPSP) were polled, they not only characterized themselves as overwhelmingly liberal, but many also said that they would discriminate against conservative colleagues, for everything from awarding grants to faculty hiring.  

So reading the theories of many political psychologists is like hearing about homosexuality from the research division of the Westboro Baptist Church, or about female psychology by a cadre of all-male scientists who are proud members of the men’s rights movement. You couldn’t be certain that their conclusions were mistaken, but you’d be right to worry about bias. People are not best situated to pass judgments on the mental health of their enemies.

Indeed, as Maria Konnikova has reviewed, the evidence that personality and psychological traits can lead a person to be conservative is weak. There are correlations—the conservatives-are-less-tolerant-of-ambiguity findings are pretty solid—but little support for cause and effect. If you want to reliably predict someone’s political views, you’re are a lot better off if you put aside the psychological tests altogether and looked at considerations that reflect people’s experiences and roles in society, such as ethnicity, sex, age, and income.

An initial assumption of rationality when it comes to people we disagree with—an assumption that they think just like we do, but have different goals, background beliefs, and priorities—is a better first start for a psychological theory, and is more moral as well, as it treats others with respect. This doesn’t preclude you from strongly disapproving of those you disagree with—you might even see them as a ”basket of deplorables”—but at least you’re treating them as legitimate agents, not pathologizing them.

My bet is that the relevant factor in variation in rationality, including moral reasoning, is not about different types of people, but different types of situations. If you want to see people at their stupidest, check out national politics, which is replete with us-vs.-them dynamics and virtue signaling, and where the cost of having silly views is harmless. Unless I’m a member of a tiny, powerful community, my beliefs about climate change or the arms deal with Iran will have no effect on the world, and so it’s not surprising that people don't work so hard to get those sorts of facts right.

It’s revelatory, then, that we do much better when the stakes are high, where being rational really matters. If I have the wrong theory of how to make scrambled eggs, they will come out too dry; if I have the wrong everyday morality, I will hurt those I love. So if you’re curious about people’s capacity for reasoning, don’t look at cases where being correct doesn’t matter and where it’s all about affiliation. Rather, look at how people cope in everyday life.

Look at the discussions that adults have over whether to buy a house or where to send their kids to school, or consider the social negotiations that occur among friends deciding where to go for dinner, planning a hike, or figuring out how to help someone who just had a baby. Or even look at a different sort of politics—the type of politics where individuals might actually make a difference, such as a town hall meeting where people discuss zoning regulations and where to put a stop sign.

My own experience is that the level of rational discourse in these situations is high. People might be self-interested, but they know that they are involved in decisions that matter, so they work to exercise their rational capacities: They make arguments, express ideas, and are receptive to the arguments and ideas of others. They sometimes even change their minds.