The Illusory Truth Effect is a Universal Bias

Trump's Bottomless Pinocchio lies with number of times he repeated the lies in public

The illusory truth effect is a well-known cognitive bias that at political propagandists and most PR organizations and marketers heavily rely on to make their points to convince people. The effect is elicited by simply repeating a lie. Over time, some people will start believing the lie is truth. Experts believe that fluency with a lie tends to create a sense of familiarity which people can misinterpret as a mental signal that the lie is truth.

A paper by European and American researchers asked if the bias applies roughly among all people with different cognitive styles. Experiments designed to measure how prone different cognitive styles are to the illusory truth effect. The researchers relied groups of people who have (i) high cognitive ability or intelligence, (ii) a high need for cognitive closure, i.e., a strong desire to avoid ambiguity, and a cognitive style of (iii) thinking a rapid and intuitive manner, or (iv) a slower and more analytic approach. The paper is now undergoing peer-review and has not yet published. The researchers conducted a series of seven experiments using a total of about 2,200 participants. Study participants would read a mix of true and false trivia statements or fake and real political headlines. In most of the studies, the participants would then complete various cognitive tests and surveys, and finally they would re-read and judge as true or false the earlier trivia statements, as well as new ones scattered among them.

The Research Digest of the British Psychological Society summarizes the results:

The researchers found the illusory truth effect across all seven studies: participants were more likely to rate trivia statements and headlines as true/real if they’d seen them previously. Crucially, the strength of this effect did not vary according to the participants’ cognitive ability or style, or need for closure. A couple of studies found some small significant associations, but these disappeared when the researchers integrated all the data.

These results suggest that we are all predisposed to believe repeated information regardless of our own particular cognitive profile. And while that might make us all susceptible to advertising and the fabrications of dishonest politicians, the researchers have a more optimistic take. “These novel findings are in line with the assertion that processing fluency is not a judgmental bias and flaw in the individual, but rather a cue to truth that is universal and epistemologically justified in most contexts”, they write. In other words, it’s not that there’s a foolish subgroup of people who are more vulnerable to the “illusory truth” effect, but rather it’s an advantageous and universal bias that’s arisen because most of the time fluency actually is a reliable signal of truth. For example, a statement that is often repeated may tend to be endorsed by more people, which could be a useful cue to its truth.

No big deal or profoundly immoral?: This effect presumably arose during evolution to help people distinguish truth from lies. In the past, politicians, ideologues, propagandists and marketers understood and exploited this trait based on experience. Knowledge of this usually helpful, human cognitive trait and how to exploit it is at least millennia old.

Given that ancient lineage, today one can assess use of the illusory truth effect in politics differently. Some people see it as normal and inescapable and thus consider it to be ‘no big deal’ or something ‘to be expected’. On the other hand, since people who exploit the illusory truth effect know what they are doing, one can see that as profoundly immoral.

Among US Presidents, Trump appears to be unique. He repeats lies so many times that those high-repetition lies were given their own label, Bottomless Pinocchios, by one fact checking group. Those lies have to be repeated at least 20 times to qualify. So far, no other politician has been ‘awarded’ their own Bottomless Pinocchio. President Trump does not know many things. But one thing he does know is how to play on illusory truth effect with no shame or moral qualm whatever. He is thus unique in that regard too.

B&B orig: 7/1/19