When it comes to how our minds work, people have a lot in common, but instead of bringing us together, our shared traits are doing a remarkably effective job of tearing us apart.

That is the implication of two new books that are impeccably timed for this fractious election season. “Good Reasonable People” by Keith Payne and “Tribal” by Michael Morris explore the ubiquitous subject of political polarization through the lens of psychology and its connection to group identity. Payne is a social psychologist; Morris is a cultural psychologist. After reading their books, I wouldn’t be surprised if they consider the distinction to be crucial. Payne and Morris both emphasize how much meaning and comfort we derive from our group identities, regardless of whether we consciously think in such terms.

It doesn’t take much for people to turn trivial differences into psychologically potent chasms between “us” and “them.” Payne cites a famous experiment by Henri Tajfel, a pioneering figure in social psychology, who found that his students heaped exorbitant significance onto a distinction as meaningless as whether they overestimated or underestimated the number of dots in a picture. The students started favoring the members of their “in group” and disparaging the members of the “out group.”

No wonder, then, that disputes involving actual stakes can harden. Payne knows firsthand how political differences can feel unbridgeable, even (or especially) when we disagree profoundly with someone we love. Payne grew up in a large family in Kentucky. He now identifies as a “secular liberal college professor” but as a teenager laughed along to Rush Limbaugh making fun of feminists “since I didn’t know any feminists.” Payne’s tiny hometown of 400 people was “100% white.”

Early in his book, he recounts the surreal experience of asking his brother, Brad, if he believed that Donald Trump had won the 2020 election. To Payne’s surprise, Brad admitted that Biden had won — but only, Brad specified, “by the letter of the law,” adding that “there was some malfeasance,” even if “it can’t be proven.” Payne could see how this conclusion allowed his brother “to come to terms with the evidence” while also letting him “hold on to the larger feeling that Biden’s win was, deep down, illegitimate.”

Payne maintains that most of us identify as the “good reasonable people” of his title. Our “psychological immune systems” kick in to discount or reject any information that would make us think otherwise. We want to believe that we seek the cold, hard truth while they wallow in self-serving lies. But Payne argues that “flexible reasoning is a bipartisan affair” and admits to doing “some mental gymnastics of my own” when faced with potentially unfavorable information about Joe Biden. We also live at a time when ostensible validation for any belief is only a click away. “People are not passive dupes,” Payne explains, “but rather they seek out the stories they want to be told. If one channel shuts down, they just find another.”

Morris, for his part, uses the term “epistemic tribalism” to describe the tendency of people to reach conclusions through “peer-instinct conformist learning” — a fancy way of saying that we’re susceptible to the influence of peers. Like Payne, he emphasizes that this phenomenon is a bipartisan affair while also identifying as an ardent liberal. Morris says that rationality isn’t our “strong suit,” but rationalizing is.

The foundation for our group identities has little to do with hatred, Morris maintains, even if it can feel as though it does. He has no patience for people who toss around terms like “toxic tribalism”; he says that our “tribal instincts” are what enabled early humans to collaborate, generating the kind of “coordinated activity” and “common knowledge” that allowed our species to flourish. If we can find a way to “harness tribal impulses,” Morris writes, we could “heal a nation.” He suggests that actual hostility may be less of a problem than “innocuous-seeming favoritism toward one’s own kind” and cites national surveys showing “that ethnic hostilities have declined steeply” in the past 50 years, even if “unequal treatment is still rampant.”