Juan Williams told Bill O'Reilly that he gets nervous at airports when he sees Muslims. For this, Williams has been roundly denounced as a bigot. But Williams' association between innocent Muslims and the perpetrators of the 9-11 attacks was less about bigotry—at least, bigotry conventionally defined —than about his mind working normally. To live in America in the post-9/11 age and not have at least some associations between Muslims and terrorism means something is wrong with you.
I am not suggesting that associating ordinary Muslims with terrorists is either rational or right. It's neither. But the association arises via a normal aspect of brain functioning, which is precisely why so many people entertain such beliefs—and why those beliefs have proved so resistant to challenge.
The left is wrong to wish the association away only by pointing out how unfair it is, because that denies the reality of how our minds work. The right is wrong to believe the association must be accurate merely because it is widespread.
It may be helpful to see how the bias works in a less incendiary context than racial profiling and terrorism. Let's say you have an upset stomach on the morning before you take a flight. (This example comes straight from my book.) You don't make much of it because you know that things that occur together are not necessarily related. Now let's say you have a second upset stomach the following week, right before you have to take another flight. Your conscious mind might still say, "coincidences happen," but now a part of your mind starts to think that flying brings on upset stomachs.
What's interesting about this is not that our unconscious minds confuse correlation with causation—our conscious minds do that all the time, too. What's interesting is that the events our unconscious minds link together are only the unusual ones. On both days you had upset stomachs, a newspaper may have been delivered to your door, but you don't associate newspaper delivery with your upset stomach.
These automatic associations make evolutionary sense. If one of our ancestors was wandering in a desert and came by a snake curled up next to the only tree on the landscape, her mind would connect not just that tree with that snake, but all trees with snakes. Illusory correlations are all about seeking out group patterns based on rare individual incidents: all trees and snakes and all flights with stomach upsets, rather than that one tree and that one snake, or that one flight and that one stomach upset. Scientists say correlation isn't causation, but, from an evolutionary point of view, if the snake-tree link is wrong, all that would happen is our ancestor would avoid all trees in the future. If the link was real and she failed to see it, she could get herself killed. Our ancestors constantly drew conclusions about their environment based on limited evidence. Waiting for causative evidence could have proved costly, whereas extrapolating causation from correlation was less costly.
The terrorist attacks of 9/11 were unusual. (Even if you take all the terrorist attacks in the world, they are still unusual.) In seeking explanations for those events, our minds are drawn to other unusual things linked to them—especially at the group level. When members of a minority group are associated with a series of unusual incidents, our minds inflate the connection between the two. As with the snake and the tree, our association is not limited to the particular members of the minority group but all members of the group.
Juan Williams pointed out on Fox that we do not associate Timothy McVeigh and the rude people who protest about homosexuality at military funerals with Christianity. But he didn't understand why our minds fail to make that connection. Illusory correlations disproportionately afflict minorities because, in making associations, we mainly link unlikely events. Whites and Christians are not minorities; they are like the newspaper delivered to our front door every day. We do not associate McVeigh with Christians any more than we associate our upset stomach with the newspaper.
Muslims are only the latest victim of illusory correlations in the United States. African-Americans have long suffered the same bias when it comes to crime. In every country on earth, you can find minority groups that get tagged with various pathologies for no better reason than that the pathologies are unusual and the minorities are minorities.
Whenever people who strongly believe in illusory correlations are challenged about their beliefs, they invariably find ways to make their behavior seem conscious and rational. Those who would explicitly link all Muslims with terrorism might point to evidence showing that some Muslims say they want to wage a war against the West, that a large preponderance of terrorist attacks today are carried out by Muslims, and so on. This is similar to our longstanding national narrative about blacks and crime.