The detours on memory lane

Do you remember where you were when you heard that planes had struck the World Trade Center? That the Challenger shuttle had exploded? Or that Nelson Mandela had been released?

Your memories may be different from mine, but not as different as Fiona Broome’s. I remember watching the live TV footage of Nelson Mandela walking to freedom after 27 years in captivity, while Broome, an author and paranormal researcher, remembers Nelson Mandela dying in prison in the 1980s.

When Broome discovered that she was not the only person to remember an alternative version of events, she started a website about what she dubbed “the Mandela Effect”. On it, she collected shared memories that seemed to contradict the historical record. (The site is no longer online but, never fear, Broome has published a 15-volume anthology of these curious recollections.)

Mandela, of course, did not die in prison. On a recent trip to South Africa, I visited Robben Island, where he and many others were incarcerated in harsh conditions, to speak to former prisoners and former prison guards, and to wander around a city emblazoned with images of the smiling, genial, elderly statesman. How could it be that anyone remembers differently?

The truth is that our memories are less reliable than we tend to think. The cognitive psychologist Ulric Neisser vividly remembered where he was when he heard that the Japanese had launched a surprise attack on Pearl Harbor on December 7 1941. He was listening to a baseball game on the radio when the broadcast was interrupted by the breaking news, and he rushed upstairs to tell his mother. Only later did Neisser realise that his memory, no matter how vivid, must be wrong. There are no radio broadcasts of baseball in December.

On January 28 1986, the Challenger space shuttle exploded shortly after launch; a spectacular and highly memorable tragedy. The morning after, Neisser and his colleague Nicole Harsch asked a group of students to write down an account of how they learnt the news. A few years later, Neisser and Harsch went back to the same people and made the same requests. The memories were complete, vivid and, for a substantial minority of people, completely different from what they had written down a few hours after the event. What’s stunning about these results is not that we forget. It’s that we remember, clearly, in detail and with great confidence, things that simply did not happen.

Other researchers have gone further. In the 1990s, the psychologist Elizabeth Loftus conducted a study that has become famous as the “Lost in the Mall” experiment. She recruited subjects and persuaded older members of each subject’s family to write a paragraph about each of four incidents in the subject’s childhood. The subjects were asked to read these short memory-prompts and then to elaborate or, if they didn’t remember the episode, to say so.

The trick in Loftus’s experiment was that one of the four incidents described was fictional. Remember that time you were lost in the mall? Sure, said some (but not all) of the subjects, serving up a string of compelling details, all of which they thought they remembered.

Loftus’s work has often been used in criminal trials, and this is a sensitive topic. For some critics, it is just one more excuse to dismiss the testimony of people who have suffered abuse. So it’s worth being clear that just because some memories are false, doesn’t mean they all are. Seventy five per cent of the subjects in Loftus’s experiments simply said that they didn’t remember being lost in a mall. The point is not that our memories always let us down, but that when they do, neither their vividness nor our own confidence is a good guide to what really happened.

We should hardly be surprised that some people have memories of things that never happened. It is easy to see how some people might have formed the vague impression that Mandela died in prison: the activist Steve Biko was killed in the custody of South African police and there were worldwide protests throughout the 1980s against the evils of apartheid. Given what we know about how memory works, a vague impression can be enough to prompt clear and specific memories of non-existent events.

Broome, for her part, insists that people should not rush to the “simplistic” explanation that our memories play tricks on us, and should instead explore the “wealth of evidence . . . that may point to parallel realities and Many Interacting Worlds”. Fine. We are all entitled to our own beliefs. Some people believe that our memories can deceive us. Some people believe that there is an alternate timeline in which Mandela died in prison, and that people, or memories, are slipping from one timeline to another.

But there is more at stake here than a theory of multiverses or a grasp of the history of South Africa. We all have subjective feelings about our beliefs, and there is no reliable connection between feeling confident about a belief, and that belief being true. Mandela multiverse believers have an unusual view of the world, but there is nothing unusual about feeling certain yet being wrong. We’ve all done that.

As Kathryn Schulz, author of Being Wrong, reminds us, we are all familiar with the lurching realisation that we were wrong. But until the moment of revelation there is no distinctive mental state that feels like being wrong. Being wrong feels exactly like being right.

Tim Harford’s children’s book, ‘The Truth Detective’ (Wren & Rook), is now available

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