Strange memories: The remains of a London bus that was destroyed by a bomb sit near Tavistock Square in London on 7 July 2005.
Credit: AFP
LIVERPOOL, UK: Our memories of major past events can be surprisingly unreliable, says a new study of the July 2005 London bombings, which found that people can easily convince themselves they've seen things that never happened.
"Some people think that our memories are like video recorders and that if you press play the memories come flooding back. It doesn't work like that at all and should not form the basis of legal decision making" said James Ost, a psychologist from the University of Portsmouth, England.
Explicit details of non-existant footage
Ost said that when DNA testing became available in the U.S. in the early 90s, 80 per cent of death row cases that were exonerated, were found to have been wrongly convicted on the strength of mistaken identity. His research demonstrates how this can happen.
To investigate how reliable our memories are, he asked people in the U.K. and Sweden if they'd seen CCTV footage of the bus bombing in the city's Tavistock Square. Eighty-four per cent of U.K. respondents said that they had, compared to 50 per cent of Swedish participants, when in fact, no such footage exists.
His research was presented last week at the British Association for the Advancement of Science (BA) Festival of Science, held in Liverpool, England.
Some respondents in the false memory investigation also gave explicit details of the events they had seen in the non-existant footage.
In response to the question, "Was the bus moving when the bomb went off?" Ost received detailed responses such as: "The bus had just stopped to let two people off when two women got on and a man. He placed the bag by his side, the woman sat down and doors closed. As the bus left there was an explosion and then everyone started to scream."
The study was conducted over two weeks in October 2005, three months after the attacks on the bus and underground system in central London. In the U.K., reports and analysis of the events continued relentlessly for weeks and months, said Ost, whereas in Sweden the bombings were headline news for only a few days.
"Fantasy proneness"
Ost said that people who were more likely to come up with false memories scored higher on a scale of "fantasy proneness" than those that did not.
"Some people who are more imaginative or more creative are better able to assimilate information, put it all together and weave a story out of it. They often have a lower threshold for accepting something as memory rather than imagination," he added.
Memory surprisingly unreliable, study shows
I used to investigate traffic accidents in Hong Kong. I'll mention a strange thing - the Chinese witnesses were generally reliable whereas foreign witnesses, usually Britons, often conflated their observations with opinions, particularly of blame. We just noted the statistical incidence without thinking much more about it. I have no idea why this was so.
Memory surprisingly unreliable...
Another aspect to this problem is the mixing of dream images with real-life images. For some images in my mind I cannot determine if they were part of my conscious past or part of a dream.