After a paroxysm of racial viciousness at the Laugh Factory Friday night, November 17, 2006, Michael Richards, the 57-year old comedian who played Kramer on Seinfeld, explained to David Letterman and his Late Night audience the following Monday, after a barrage of negative publicity: “I’m not a racist. That’s what’s so insane about this.”

Michael’s shattered demeanor and heartfelt repentance leaves us with what I shall call Kramer’s Conundrum: how can someone who spews racial epithets genuinely believe he is not a racist? The answer is to be found in the difference between our conscious and unconscious attitudes, and our public and private thoughts.

Consciously and publicly, Michael Richards is probably not a racist. Unconsciously and privately, however, he is. So am I. So are you.

Consciously and publicly, most of us are colorblind. And most of us, most of the time, under most conditions, believe and act on that cultural requisite. You’d have to be insane to publicly utter racist remarks in today’s society … or temporarily insane, which both science and the law recognize as being sometimes triggered by anger. And alcohol — recall Mel Gibson’s drunken eruption about Jews, or the college Frat boys slurring alcohol-induced insanities about blacks and slavery in Sacha Baron Cohen’s film Borat.

The insidiousness of racism is due to the fact that it arises out of the deep recesses of our unconscious. We may be utterly unaware of it, yet it lurks there ready to erupt under certain circumstances. How can we know this? Even without anger and alcohol, Harvard scientists have found a method in an instrument called the Implicit Association Test (IAT), which asks subjects to pair words and concepts. The more closely associated the words and concepts are, the quicker the response to them will be in the key-pressing sorting task (try it yourself at https://implicit.harvard.edu/implicit/).

The race test firsts asks you to sort black and white faces into one of two categories: European American and African American. Easy. Next you are asked to sort a list of words (Joy, Terrible, Love, Agony, Peace, Horrible, Wonderful, Nasty, Pleasure, Evil, Glorious, Awful, Laughter, Failure, Happy, Hurt) into one of two categories: Good and Bad. No problem.

The next task is a little more complicated. The words and black and white faces appear on the screen one at a time, and you sort them into one of these categories: African American/Good or European American/Bad. Again you match the words with the concepts of good or bad, and faces with national origin. So the word “joy” would go into the first category and a white face would go into the second category. This sorting goes noticeably slower, but you might expect that since the combined categories are more cognitively complex.

Unfortunately, the final sorting task puts the lie to that rationalization: This time you sort the words and faces into the categories European American/Good or African American/Bad. Tellingly (and distressingly) this sort goes much faster than the previous sort. I was much quicker to associate words like “joy,” “love,” and “pleasure” with European American/Good than I did with African American/Good.

I consider myself about as socially liberal as you can get (I’m a libertarian), and yet on a scale that includes “slight,” “moderate,” and “strong,” the program concluded: “Your data suggest a strong automatic preference for European American compared to African American.” What? “The interpretation is described as ‘automatic preference for European American’ if you responded faster when European American faces and Good words were classified with the same key than when African American faces and Good words were classified with the same key.”

But I’m not a racist. How can this be? It turns out that this subconscious association of good with European Americans is true for everyone, even African Americans, no matter how color blind we all claim to be. Such is the power of culture.

We are by nature sorters. Evolutionists theorize that we evolved in small bands of hunter-gatherers where there was a selection for within-group amity and between-group enmity. With our fellow in-group members, we are cooperative and altruistic. Unfortunately, the down side to this pro-social bonding is that we are also quite tribal and xenophobic to out-group members.

This natural tendency to sort people into Within-Group/Good and Between-Group/Bad is shaped by culture, such that all Americans, including those whose ancestry is African, implicitly inculcate the cultural association, which includes additional prejudices.

The IAT, in fact, also demonstrates that we prefer young to old, thin to fat, straight to gay, and such associations as family-females and career-males, liberal arts-females and science-males. Such associations bubble just below the surface, inhibited by cultural restraints but susceptible to eruption under extreme inebriation or duress.

Michael Richards’ sin was his deed; his thoughts are the sin of all humanity. Only when all people are considered to be members of one global in-group (in principle, if not in practice) can we begin to attenuate these out-group associations. But it won’t be easy. Vigilance is the watchword of both freedom and dignity.

We should accept Mr. Richards’ apology for losing his temper and acting out those hateful thoughts. Perhaps we also ought to thank him for having the courage to confess in public what far too many of us still harbor in private, often in the privacy of our unconscious minds. As the Russian novelist Fyodor Dostoyevsky wrote: “Every man has reminiscences which he would not tell to everyone but only his friends. He has other matters in his mind which he would not reveal even to his friends, but only to himself, and that in secret. But there are other things which a man is afraid to tell even to himself, and every decent man has a number of such things stored away in his mind.”

This article was originally published in the New York Times.