Hearing or reading things like this (or this) continue to trouble me profoundly. It is tempting to believe that these are problems of simple ignorance-- problems that, with a sufficiently large bullhorn, can be remedied with simple but forceful education. However, after recently finishing Robert Wright's The Moral Animal, a mid-1990s study on evolutionary psychology, I have come to suspect that their is something deeper and more firmly entrenched at work.
The human capacity for self-deception is well...practically limitless. But if, as I believe, most of us pride ourselves on searching for and accepting "truth," why is their self-deception? To put it simply, it helps (or helped) us reproduce better, in two ways. The simple version of the argument goes as follows: Under Darwinism, the (unconscious?) goal of organisms is to perpetuate their genes through their offspring. Males in almost all species, who can conceivably reproduce with many females during any reproductive cycle, have the ability to have many, many more offspring over their lifetime than do females, who are generally burdened with gestating and raising the offspring, which limits their lifetime fertility. Thus males seek after raw quantity of offspring, while females focus more on the quality of the few offspring they are able to produce, hoping that an achieved fitness will enable those offspring to reproduce prodigiously in future generations.
The first reason for which self-deception may have evolved has to do with how females go about converting their few offspring into worthy future reproducers. Females primarily pursue quality of offspring through male parental investment (MPI). A male's MPI will likely inhibit the number of other females with which he could reproduce. Thus, a male has an incentive to deceive the female regarding the level of MPI he is willing to provide. In response, females would have likely developed a mental mechanism to detect deception. But it is the male's counter-measure which is truly intriguing. At some point, males may have developed a mechanism which heightened the sincerity of their deception by deceiving the males themselves regarding their less-than-noble intentions. Being utterly convinced of their intention to provide a high level of MPI enabled those males to be utterly convincing to females. Ergo, those males who could self-deceive reproduced more than those males who did not possess the new fangled mental equipment. (Note that over a period of thousands of years, the mental machinery for deception, self-deception, and deceptiveness detection would have spread through both males and females in the population). Whew, that took longer than expected.
The second reason for which self-deception may have evolved also involves sexual selection. Under this theory, men are better able to achieve status and power through deception, or rather deception is one apt tool among many that males (and females) are able to call upon to achieve status and power. Status and power translate into higher reproductive potential in males. Again, self-deception enabled the ambitious to be more able deceivers, and thus to achieve status and power more readily.
Now, what was all this about? My point, going back to the introduction, is that at some point in our evolution, human beings developed a capacity for self-deception. Originally, this self-deception was designed for purely reproductive purposes. It may still serve that purpose or it may not. However it is unlikely to have become dormant merely because its usefulness has declined. (Note: This is because this capacity would have taken thousands and tens of thousands of years to develop through natural selection. It would not disappear in the few hundred years since our species outgrew its usefulness, if we have at all). Therefore, nearly all humans would likely possess this unconscious capacity to deceive ourselves, all the better to deceive others. I make the point about self-deceptions unconscious nature to show that self-deception is not malicious, or at least not intentionally so.
So I pointed out a couple of examples in the first sentence of incredibly bone-headed behavior as evidence for human being's capacity for self-deception. I say this without sarcasm or malice, because being a human trait, self-deception is one with which we are all afflicted. It actually inspires me to be more charitable towards those with whom I disagree. Many of them believe some things which are false (and even demonstrably so, not just a mere difference of opinion). However, they believe them for powerful reasons that have little or nothing to do with the truth or falsity of the idea...and they are not even aware of it. The phenomenon we call cognitive dissonance would have arisen as part of our capacity for self-deception, in fact to deepen it. Self-deception is still a tool in the search for status and power. Believing certain false ideas because of self-deception, and therefore being a very believer in that idea, may have little utility in the larger population or among other communities, but could be incredibly useful in signaling one's status or potential in one's own community. For example, take the "birthers." I can predict, with near certainty, that there are few, if any birthers, on the faculties at Harvard or Yale. Believing such a thing, or at least publicizing it to others, would cause an extreme loss of face, resulting in loss of standing in the intellectual community. (This does not, of course, preclude faculty members at Harvard and Yale being self-deceived in other areas, which actually contribute to their status and standing). However, a recent poll showed that 53% of Southerners polled said they did not believe or were not sure that President Obama was born in the U.S. For a variety of factors, involving politics, racial history, and our baser emotions, being a "birther" may have some utility for some people in the South.
As I alluded to before, humanity's capacity for self-deception is a double-edged sword. I can point fingers at the absurdities that other folks believe, while being ignorant of the many ways in which I have deceived myself into believe a host of other half-truths and silliness. In sum, I am encouraged by Wright's admonition towards the close of The Moral Animal, asking us to be more generous with one another and more introspective and thoughtful about our own ideas. The self-deceived need not remain so.