John Tierney of The New York Times offers a really important report on the Society for Personality and Social Psychology’s recent annual meeting. As Tierney writes, “Some of the world’s pre-eminent experts on bias discovered an unexpected form of it at their annual meeting.”

It all started when Jonathan Haidt, a social psychologist at the University of Virginia, took a poll of his audience at the meeting:

He polled his audience at the San Antonio Convention Center, starting by asking how many considered themselves politically liberal. A sea of hands appeared, and Dr. Haidt estimated that liberals made up 80 percent of the 1,000 psychologists in the ballroom. When he asked for centrists and libertarians, he spotted fewer than three dozen hands. And then, when he asked for conservatives, he counted a grand total of three.

Haidt responded with this simple statement: “This is a statistically impossible lack of diversity.” Haidt then pointed to studies showing that while 20 percent of Americans consider themselves to be liberal, fully 40 percent identify themselves as conservatives.

The psychologist then proceeded to define his colleagues as a “tribal-moral community” that has its own set of “sacred values.” Those values, he argues, blind the academic tribe to its own forms of discrimination. While they see discrimination against women and minorities without difficulty, they blind themselves to their own prejudice against conservatives. Even their jokes assume that everyone is a liberal.

Professor Haidt went so far as to propose a new form of affirmative action for conservatives. He also suggested that most liberal groups tend to protest yesterday’s forms of discrimination and often miss the more urgent discrimination problems of the present.

In any event, Professor Haidt’s address represented a rare moment of candor and confession in an academic meeting. The open admission of bias against conservatives was a very rare achievement.

Beyond this, Haidt’s concept of the academic guild as a “tribal-moral community” is genuinely helpful. Indeed, his insights distilled into this phrase are transportable to many other fields of interest. We are all members of some moral tribe. Hats off to Professor Haidt for making that truth so clear — and for documenting the existence of bias against conservatives in academia.