Both the blogosphere and the press have noted the important recent Pew survey of American Muslim opinion. Ali Eteraz makes some good points about it in this post. On the positive side, the survey provides extensive evidence that most American Muslims are assimilated, opposed to Muslim religious extremism, and generally happy with their lives in the United States. In these respects, they differ greatly from their co-religionists in most majority-Muslim countries and in Western Europe.

However, there are some skunks at this otherwise wonderful garden party. To me, the most worrisome is not the widely cited finding that 13% of American Muslims support suicide bombing in at least "rare" instances. It is the fact that only 40 percent agree that "groups of Arabs" committed the 9/11 attacks, while 28% rejected this proposition, and 32% refused to give an opinion. Public opinion researchers have long recognized that survey respondents sometimes conceal views that are considered socially unacceptable. At least some of the 32% who said that they had no opinion in fact agree with the 28% who believe that someone other than Arab terrorists committed the 9/11 atrocities. Ignorance on this point is more than a detail. If you believe that 9/11 wasn't really perpetrated by Arab Muslim terrorists, then you are unlikely to support any efforts to retaliate against the perpetrators and track them down. Any such efforts will seem like unjustified persecution of Muslims. It is not, surprising, therefore, that a 48% plurality of respondents to the survey oppose the war in Afghanistan, as compared to 35% who support it (despite divisions over the war in Iraq, polls show that non-Muslim Americans overwhelmingly support the war in Afghanistan).

This kind of ignorance is far more prevalent among Muslims in other countries than in the US. As I note in this article(pg. 275), surveys taken in majority Muslim countries have a much higher rate of respondents who reject the proposition that the 9/11 attacks were perpetrated by groups of Arabs. That was the answer given by 89% of Kuwaitis, 86% of Pakistanis, and 58% of Lebanese, among others. Many Muslims in Western Europe hold similar views. Pew's 2005 international survey of Muslim opinion (pg. 5) found that 56 percent of British Muslims, 46 percent of French Muslims, and 44 percent of Spanish Muslims also believe that "groups of Arabs" did not carry out the 9/11 attacks.

As I have argued in much of my academic work, ordinary citizens have strong incentives to be "rationally ignorant" about politics. Because there is very little chance that any one vote will be decisive to the outcome of an election, there is little incentive to invest time and energy in acquiring political information. Muslims are far from unique in this regard. But it is also rational for citizens to do a poor job of analyzing the information they do have, a point I made in the article linked above and that Bryan Caplan drives home in his excellent recent book. Because individual citizens do not pay any cost for clinging to false beliefs about politics, they are likely to embrace emotionally satisfying falsehoods rather than search assiduously for the truth. Bryan calls this "rational irrationality."

At least in the case of Muslims living in the West, I suspect that rational irrationality is more responsible for ignorance about 9/11 than pure rational ignorance. Even the most ignorant person living in the West has likely been exposed to numerous news reports identifying Al Qaeda as the perpetrators of 9/11. Meanwhile, there is no evidence supporting the proposition that any other group was responsible. Muslims who persist in rejecting the evidence probably do so because they are unwilling to believe that their own coreligionists perpetrated such a horrendous atrocity, and are unwilling to give objective consideration to evidence that goes against their preconceptions.

Again, Muslims are far from unique in refusing to give a fair shake to evidence that undercuts their political or religious views. Numerous studies show that this is a trait that cuts across ethnic, religious, and ideological lines (I cite some in my article linked above). Muslims are not even unique in their reluctance to believe that members of their own group could be responsible for terrible atrocities. For decades, the majority of white Americans refused to believe that Jim Crow segregation and other policies instituted by whites were responsible for the plight of African-Americans.

Nonetheless, Muslim ignorance about 9/11 is an important and underrated problem, one that makes it far more difficult to attract Muslim support for the War on Terror and for efforts to curb radical Islamism. Unfortunately, there may not be any easy solution. Still, we should start by recognizing the scope of the problem and the degree to which it exacerbates anti-Americanism among Muslims.

UPDATE: The link to Ali Eteraz's post on the Pew Survey seems to be dead. I am leaving it up in case the people at Huffington Post (where Etaraz blogs) restore it.

UPDATE #2: Thanks to commenter "Serenity Now," we now have a working link to the Eteraz post.

UPDATE #3: Some commenters on this post have been trying to downplay the significance of the data I cite by pointing out that various other groups are also ignorant about important issues. A few of the analogies they make seem apt, while others are much less so. In any case, I don't deny (and in fact emphasized in the post) that rational ignorance and irrationality about politics are common among many groups. The fact that other groups are ignorant about many issues doesn't mean that Muslim ignorance about 9/11 isn't a serious problem.