Last year, John Tooby, a founder of evolutionary psychology, was asked by the website Edge.org what scientific concept should be more widely known. He argued for something called the "coalition instinct."
In our natural environment, humans form coalitions. Coalitions are slightly different from tribes, families or nations in that those are all groups we are involuntarily born into. Coalitions are the teams we join.
"Coalitions," Mr. Tooby explained, "are sets of individuals interpreted by their members and/or by others as sharing a common abstract identity." The coalition instinct is a bundle of "programs" that "enable us and induce us to form, maintain, join, support, recognize, defend, defect from, factionalize, exploit, resist, subordinate, distrust, dislike, oppose and attack coalitions." Most animals don't have this instinct, and none have it as finely honed as humans do.
Because coalitions are formed to protect the interests of their members, we have a remarkable ability to forgive behavior when it is done by our teammates and condemn similar behavior when it is done by members of a rival coalition. "This," Mr. Tooby said, "is why group beliefs are free to be so weird."
And that brings me to last week. Kanye West, a legendarily skilled self-promoter, had some kind words for Candace Owens, a young African-American conservative activist. "I love the way Candace Owens thinks," the rap mogul tweeted. He then doubled down and praised President Donald Trump.
Many liberals reacted with unbridled moral horror and a seething sense of betrayal. Meanwhile, many avowed conservatives — particularly those who are most ostentatiously in the Trump coalition, and who had spent years ridiculing Mr. West — suddenly embraced him as a free-thinking hero.
On one level, this is just another example of the hypocrisy and opportunism that saturates so much of our politics today. But hypocrisy can be an underappreciated sin because it illuminates a principle: Without a standard to violate, there's no hypocrisy.
The challenge of the coalition instinct is that it blinds us to the violations of our own team while exaggerating the violations of rival coalitions. As George W. Bush once put it, "Too often, we judge other groups by their worst examples while judging ourselves by our best intentions."
Over the weekend, Mr. Trump held a rally at the same time as the White House Correspondents' Association Dinner. CNN ran a graphic from the latter event's red carpet: "Trump Skips Event Honoring First Amendment to Rally His Base."
Now, it's true that the annual dinner is supposed to honor the First Amendment. But come on. The event has long been a riot of narcissistic self-adulation and Hollywood envy, which explains the red carpet in the first place.
Days later, the air is still thick with conservative denunciations of Michelle Wolf's caustic routine — and with liberal defenses of it.
Conservatives insist, rightly, that Ms. Wolf was crude and nasty toward White House press secretary Sarah Huckabee Sanders. Ms. Wolf's liberal defenders, who'd never accept the comedian's vitriol if it were aimed at one of their own, ludicrously celebrate her courage for speaking truth to power.
Liberals have a better argument when they note that Ms. Sanders and her conservative defenders have been, at best, blind to Mr. Trump's even cruder personal attacks on women and others. When Mr. Trump says indefensible things, those in his coalition leap to his immediate defense and say, in effect, "Lighten up, don't be so sensitive."
Indeed, Ms. Sanders' father, former Arkansas Gov. Mike Huckabee, is understandably angered by the attacks on his daughter. But he is also apparently oblivious to the fact that he routinely denounces "snowflakes" who can't take a joke (or what he passes off as jokes).
Of course, last week was just the latest chapter in an ancient story. Humans have always come preloaded with the coalition instinct.
What feels different these days is that, more and more, one hears people jettisoning universal norms — free speech, constitutional fidelity, rhetorical decency — in favor of relativistic ones that simply suit the needs of one coalitional identity group or another. Some on the left now denounce free speech solely because it is a threat to their power. Many Trump supporters wave off his rhetorical grotesqueries because "he fights!"
Rather than simple blindness to our hypocritical violations of standards, we're declaring war on the standards themselves. If this trend continues, we may get less hypocrisy and more open war between coalitions.
Jonah Goldberg is a fellow at the American Enterprise Institute and a senior editor of National Review. His new book, "The Suicide of the West," was released on April 24. His email is firstname.lastname@example.org. Twitter: @JonahNRO.