You remember exactly where you were on 9/11, but is that memory accurate?
Twenty-five years on, many people can still recall the exact moment they heard about the September 11 attacks. Psychologists call this a flashbulb memory. But how reliable are these memories?
As the world watched in shock as the Twin Towers collapsed, psychologists saw a unique opportunity to study the phenomenon of flashbulb memories – detailed, vivid memories of the moment someone hears emotionally shocking news. Leiden psychologist Gezinus Wolters also researched these memories of 9/11.
‘In this kind of research’, says Wolters, ‘we ask people where they were, how they heard the news, what they were doing, what time it was and who else was with them. If you can answer at least four of these five questions, that counts as a flashbulb memory.’ Wolters studied both people aged 65 and over and students. ‘Both groups turned out to have equally strong flashbulb memories.’
Vivid, but not always accurate
Many people experience these memories as vivid, with details they feel certain are correct. Yet small errors can creep into these memories over the years. ‘People sometimes say they heard the news on the radio, for example, when they had previously said they heard it on TV’, says Wolters. ‘Or they remember being alone, when shortly after the attacks they said they were with someone else when they heard the news. These memories are not one hundred per cent reliable, as some people believe.’
These memories may not be completely reliable, but they are usually more or less accurate. ‘Only a small number of details turn out to be wrong.’ What stands out most is how certain people feel about their memories: even after many years, they often still say they are 100% sure – even about the incorrect details.
Emotional shock
According to Wolters, the idea that a flashbulb memory is a separate type of memory, recorded like a kind of photograph, is not correct. ‘It’s an ordinary memory process that occurs in an unusual situation. The emotional shock, or arousal, leads to the rapid formation of a memory trace. Retelling the event repeatedly also helps to strengthen the memory further.’
Regional differences
Whether an event becomes a flashbulb memory depends on how close and how meaningful it is to the person concerned. ‘The Hillsborough disaster in England or the Heysel Stadium disaster in Belgium mainly created this kind of memory locally’, says Wolters. ‘For us in the Netherlands, these events were just a small item in the newspaper. Hardly anyone here has vivid memories of them.’
Kennedy’s assassination
Flashbulb memories stay with people for a lifetime. Wolters himself, for instance, still has a vivid memory of the moment he heard about the assassination of John F. Kennedy in 1963. ‘I was a student in Groningen and took the bus to my parents’ house. When I got there, my parents were watching TV, which showed that Kennedy had been assassinated. That memory is still just as vivid as it was 20 or 30 years ago.’
Gezinus Wolters (b. 1943) studied flashbulb memories in 2003 and 2004, prompted by the 11 September 2001 attacks. Since retiring in 2008, he has remained affiliated with the Cognitive Psychology unit as a visiting lecturer. He also regularly appears as an expert witness in court cases, advising the court on the reliability of statements made by victims and witnesses.