Familiarity breeds belief

“A reliable way to make people believe in falsehoods is frequent repetition, because familiarity is not easily distinguished from truth.”

The words are Daniel Kahneman’s from his Thinking Fast, Thinking Slow. Both a young friend of mine and one of my sons had repeatedly urged me to read this excellent book, but though I started it twice, somehow on each occasion I let other things take over and gave up before I’d got far.

Now, however, I’m making good progress and delighted by the insights it provides me, not least the sentiment I’ve just quoted.

Daniel Kahneman.
A Nobel-prize winner I should have paid attention to earlier

There’s an old principle that I’ve always believed, that the truth is often the best thing to tell, if only because it’s the version of events you know best so you’re less likely to get it wrong and end up contradicting yourself. The truth is easy because it’s familiar. It took Kahneman to point out the converse: if it’s familiar, there’s a serious risk you’ll take it for the truth whether it is or isn’t. As he points out, you don’t even have to repeat the entire statement to convince someone of a falsehood.

People who were repeatedly exposed to the phrase “the body temperature of a chicken” were more likely to accept as true the statement that “the body temperature of a chicken is 144°” (or any other arbitrary number). The familiarity of one phrase in the statement sufficed to make the whole statement feel familiar, and therefore true.

We all know that mechanism from within ourselves. Someone tells us a piece of news, and if our first reaction is, “I’ve heard that” then not far behind will be the notion, “it must be true”. If we reflect on the information more carefully – the slow thinking, or “System 2”, of Kahneman’s analysis – we may well reject it, but our first reaction is to believe what we’ve already heard. And how many people go to that analytic phase? As Kahneman points out, System 1, the intuitive reaction is easy; System 2 is effortful and difficult.

Incidentally, I’m making no claim to superiority here: these are statements about all of us – I know that System 2 thinking is as laborious for me as for anyone, and I’m as inclined as everyone else to go with System 1 gut feel if possible.

So, say it often enough, and a proportion of the US electorate will believe that Barack Obama was born outside the United States. The evidence is strongly against that belief, but analysis of evidence is a System 2 activity. Even less considered is the seldom-mentioned view that it’s irrelevant anyway: the US Constitution doesn’t require candidates for the presidency to be born in the States, only to be born American. So John McCain could run, though he was born in the Panama Canal zone, and George Romney (father of Mitt) could be a candidate too, in 1968, despite being born in Mexico.

Again, absorbing that information requires System 2 behaviour.

Now consider the Fox News announcement that the attacker at the Quebec Mosque was himself a Muslim. The suggestion was that the six worshippers killed and the nineteen wounded had been targeted by a Muslim terrorist.

The story was untrue. The killer was a Canadian known to the police for his extreme right-wing views. Fox eventually admitted as much and deleted the item. By then, though, it had spread like wildfire across social media.

Would you be prepared to bet that this false story, made familiar by repetition, is now disbelieved by everyone?

Trump, whose favourite news channel is Fox, is emerging as a master of this kind of disinformation. Faced with the refusal of the scandal which may, in time, sink him – his campaign’s contacts with Russia, a story that feels like a new Watergate – he has hit back by accusing Barack Obama of having wiretapped Trump tower. 

Repeatedly hit back.

Trump has offered no evidence for his claim. Indeed, despite having decried unsourced stories himself, he has given no source for it. But evidence and awareness of hypocrisy are System 2 activities.

I don’t know what will come of the accusations. There have been some authoritative denials already but someone may emerge with some supporting information. It doesn’t matter. The story’s out there. It’s being repeated. It’ll become familiar. Many will see it as true. Not just about Obama, either: this is part of a flow of apparent information which will ultimately leave many with the feeling that any opponent of Trump’s is devious or even evil.

The converse also applies. Trump keeps telling us how much he’s achieved and how well his administration is running. In reality, there have been no achievements and the administration is chaotic. Again, it doesn’t matter. His claims will be picked up. They’ll become familiar. They’ll be believed.

There’s not much that’s funny about the post-truth age. But at least we can be grateful to Daniel Kanehman for exposing the mechanisms by which it works.