Authors: Claudia Hammond
The incident people in the British study found hardest to date was the hijacking of an Ethiopian Airlines plane, which crashed in the Indian Ocean in 1996. In every age group most people had no idea when it happened and assumed it must have been a very long time ago. Compared with the other events on the list that took place that year, such as the opening of the Channel Tunnel and the Baltic Ferry disaster, I can’t say I remember it myself. But when I looked it up I discovered the most extraordinary story, one that wouldn’t be easy to forget. On a flight from Addis Ababa to Nairobi, three young men charged the cockpit, shouting into the intercom that they had just been released from prison in Ethiopia and wanted political asylum because their anti-government views left them in danger in their own country. They claimed to have a bomb, which later turned out to be a bottle of drink, and had chosen this particular aeroplane on the basis of an article they’d read in the in-flight magazine, which said it could fly all the way to Australia without refuelling. This, they thought, would suit them perfectly. What they didn’t realise was that because the plane was only on a six-hour stopover flight, the fuel-tank wasn’t full. The pilots pleaded with them, but the hijackers were convinced they were lying and insisted they steer the plane
in the direction of Australia. Knowing they couldn’t make it that far, the pilots continued along the coast in the hope of making an emergency landing at the airport in the Comoros Islands just as the fuel ran out. This hijacking was unusual because for four hours the hijackers allowed life in the cabin to proceed as though little had happened. The passengers were aware of the hijackers and even made plans to overpower them once they’d landed, but they had no idea of the arguments occurring in the cockpit. They continued to eat, read and, rather surprisingly considering the circumstances, to sleep.
As they approached the Comoros Islands, just as the pilot predicted, the fuel started to run low. He knew this was his one and only opportunity to land the plane safely, so he began dropping altitude. As soon as they noticed what was happening, the hijackers wrestled for the controls and the disruption caused the pilot to miss the runway and ditch the plane in shallow water just off the island he was aiming for. This is one of the few occasions in airline history that a plane this large has landed on water. Despite the diagrams in the safety instructions where planes float on the surface of the water while passengers calmly remove their high heels and slide down the emergency chutes ready to blow their whistles to attract attention, large planes rarely float. They sink. And even landing in shallow water, this crash was to prove fatal for many of the passengers. One side of the plane hit a coral reef, causing it to break up. Scuba divers on holiday rushed to the rescue alongside locals, but still 123 of the 175 passengers and crew died in the crash. Today the incident is told as a cautionary tale in
safety training for airline crews as many of the passengers who survived the impact and managed to get their life jackets on made the fatal error of inflating them
before
escaping from the cabin – the life-jackets pushed them up towards the roof of the plane, which was by now full of water and the people drowned.
The pilot, Leul Abate, survived the ordeal and was given an award for his bravery. One of those who lost his life was the cameraman and photojournalist Mohammed Amin, famous for the pictures he took of the Ethiopian famine of 1984. Coincidentally, by the time of the hijacking, he had become the publisher of the Ethiopian Airlines’ in-flight magazine, the same magazine used by the hijackers to decide which plane to seize in their attempt to escape from the country.
As I said before, this really is an extraordinary story and the chances are that I’ll remember it the next time I hear it mentioned, and probably so will you. But because knowledge doesn’t improve the dating of events which happen in our lifetimes, we still won’t necessarily remember how long ago it took place. The event isn’t tethered to a particular date for us. The fact that so many people don’t remember this hijacking highlights one of the difficulties of studying autobiographical memory and working out the frequency of the telescoping of time. You can’t test somebody on their ability to estimate the date of the Ethiopian hijacking if they’ve never heard of it. Studying short-term memory is easy; you can give a whole group of people the same list of words to memorise, test them under different conditions and score them on their accuracy. But while
news events may seem to be universal, they aren’t. If you’ve never heard of an event like the Ethiopian hijacking you will never remember the date, however fantastic your memory. An alternative solution is to test people’s autobiographical memory for personal events instead, but this brings two new problems: not only are everyone’s memories different, but they are hard to verify. I remember going with my grandfather to an air show where a motorcyclist attempted to jump over a line of double-decker buses. It was the climax of the day and hundreds of us stood watching. It looked like an impossible task. Would he manage it? Surely he’d crash. He started far, far away from the buses, roared up the ramp and took off. Then, as he hovered in the air, the crowd gasped as it became clear he wouldn’t make it. He fell onto the buses, glancing off the edge of a roof and landing on the grass. The ambulance staff rushed to rescue him, but it was too late. He was lifted onto a stretcher and an orange blanket was pulled over his head. I remember it well. My grandfather tried to stop us from looking and took us to find the car. Or maybe it didn’t happen like this at all. My sister tells me it wasn’t an air show, but an agricultural show; it was our elderly neighbour who took us, not our grandfather; and the motorcyclist wasn’t killed; he did fall, but he only injured his leg. My sister is four years older than me and she’s probably right, but our differing stories illustrate just how tricky it is to assess autobiographical memory and the part it plays in time perception. If every memory needs verifying, how are we to work out who’s good at it and who’s not?
TAKE TWO ITEMS A DAY FOR FIVE YEARS
Psychologists have avoided some of these problems by asking people where they were on a certain date and then verifying the answers via diaries or relatives. But one researcher tried something a little more extreme, a technique of which I suspect Gordon Bell might approve. Back in 1972 Marigold Linton’s idea was to have someone write down everything that happened to them, however insignificant it might seem. Then in years to come the accuracy of each autobiographical memory and its place in time could be tested. Looking around for a suitable guinea pig for such a study, Marigold Linton sought an individual who was easily accessible, reliable and, crucially, prepared to take part in a daily study with a five-year commitment. Following in the footsteps of many a scientist in the past, she decided there was only one subject who would do for the job – herself. Her conscientious nature was never in doubt – as a member of the Cahuilla-Cupeno tribe of Native Americans, she was the first ever person from a Californian reservation to attend college. On opening her first report card at college and seeing she had straight As, she was so surprised that she tried to return it to the office, convinced it must belong to someone else. Nevertheless she found researching her own memory far more challenging than she could ever have predicted.
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She called the study ‘Take-two-items-a-day-for-five-years’, although really that name only covered the first part of the study. In fact every evening for 10 years she sat down in her home in Salt Lake City, took a fresh white
filing card measuring six inches by four and typed three lines describing an event that had happened to her that day. She considered each experience for a moment, then rated its confusability, emotionality, importance, datability, the likelihood that she would discuss it with others and whether it belonged to a sequence (e.g. one lecture in a course of twelve). On the reverse of the card she wrote the date and then shuffled it in among the other cards from that month. The first day of each month was a testing day (in both senses of the word as it transpired) where she would select two of the previous months’ cards at random and guess which occurrence happened first and the date, all the while timing herself with a stopwatch. The idea was to assess her ability at a very particular type of time perception – setting events in their place in time.
The Marigold Linton approach – noting down daily memories for testing on a later occasion – has been attempted with larger groups of people too. The problem is that this test can never provide a measure of autobiographical memory as a whole, only of the events a person selects. Inevitably these will be the most outstanding and therefore the best-encoded in their memory. So the selectivity of memory affects what can be tested later on – you’re unlikely to write down that you dropped a letter on the ground while you were trying to post it, but because you don’t record the incident, you can’t be tested on your memory of it either. Yet these diary studies do begin to give an insight into which events we remember, how we order them and how those autobiographical memories begin to build up a sense within us both of time and of our life history.
Linton replaced each index card after testing, which meant that by chance some events would come up more frequently than others. It was these events which she became best at dating, demonstrating the more a memory is discussed or contemplated, the more likely you are not only to recall the event, but to remember the date. The events of 9/11 would be an extreme example of this, the one incident whose date we can never forget, because it is not only mentioned frequently, but is named after the date it took place. When it comes to personal memories, we might expect to remember best the moments where things went wrong, but Linton found the opposite. Again this is probably down to mental rehearsal. We might worry for a while about the time we embarrassed ourselves in front of a roomful of people, but we don’t look back on photos of the day in the same way we do with our eighteenth birthdays (although with more and more moments – good and bad – documented on social-networking sites, this might change in the future).
This is known as the fading effect bias – the somewhat counter-intuitive idea that while the negative loses its sting in the memory as time passes, the positive doesn’t lose its joy. The theoretical explanation is that discussing an incident from the past has a different impact on that memory, depending on whether it was good or bad. So every time you talk about the good old days you relive that memory and the warm feelings that accompanied it, but with the exception of the extreme case of post-traumatic stress disorder, unhappy events gradually lose their power the more we talk about them. This allows us to cope and move
on.
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We even remember successes as having taken place more recently and embarrassments as more distant in the past, as though time warps to protect our self-esteem.
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In a series of studies using diaries, the psychologist John Skowronski asked students to keep a daily record of one occurrence that was unlikely to happen more than once in a term. He found the results fascinating and confesses that one of the attractions of this work is the amount people reveal about themselves anonymously, even when they’re asked to be discreet. Two months later each student was given two of their events at random and had to guess which came first, as well as the day and the date. Women did slightly better than men, but still usually got the date wrong. Some hypothesise that women score higher because they tend to have the calendar-keeping job in a family, but these were young students, so I would question whether that would apply. Perhaps they initiated and arranged more social events, which led to them knowing the date. Not surprisingly students were more likely to get the date wrong the longer ago the event took place; for every week that passed they were out by one more day. The day was easier to get right than that date, so people might have known it was a Tuesday, but found it hard to assess which Tuesday it might have been. Weekends had boundaries of their own and were clearly delineated, so people might feel certain an event happened either on a Monday or Tuesday, but would never say it might have been a Sunday or a Monday.
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It seems that an event’s place in time comes low down in our memory’s priorities. After keeping daily records for six years, a Dutch psychologist, Willem Wagenaar, found
that the what, who and where of an event were well-remembered, but the
when
simply didn’t feature as much.
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The reason I’m interested in these studies is that they can tell us more about the phenomenon of telescoping – when you think events happened more recently than they actually did – and crucially, whether this contributes to the sensation that time speeds up as we get older.
The results of these studies reveal that telescoping can occur with personal memories, just as it does with the recall of news stories. It makes no difference whether the event was pleasant or unpleasant, and Skowronski found once again that if an event was poorly remembered we tend to assume it happened longer ago than it really did. At first sight this seems to make sense and fits in with the clarity of memory hypothesis. We know memories fade, so if someone can’t remember an event very well you would expect them to assume it must have happened long ago. These theories, sometimes known as ‘trace strength’ theories, date back to the nineteenth century; the stronger a trace we have for a memory, the more recent we assume it to be. But in fact this theory doesn’t hold. Although we do assume poorly remembered occasions happened in the distant past, when there’s a personal experience we remember well, we are often bang on with the right date, especially if it was during the last four months.
Nevertheless we do get some dates wrong, and it can matter – and not just in pub quizzes. This phenomenon can even affect public policy. Surveys involving questions about events inform everything from policies on anti-social behaviour to insurance premiums. When a pollster phones
up it is standard practice to put a time-frame on the events they are discussing. If they want to monitor your use of local leisure facilities, they are not interested in knowing that you once went to the local swimming pool in 1999; they want to know about your behaviour in the last 12 months. This helps them to ensure that their findings are up to date. If the local council commissions research to assess the impact of their policy of increasing community policing in the streets in your area, they don’t want you to remember an incident where you felt threatened five years previously. They need you to recall only incidents from the last year. The problem is that people often get things wrong. When I took part in a local crime survey, I wanted to tell them about the time when two 10-year-old boys on their way home from school pointed a plastic gun at me and shouted, ‘We’re going to shoot you up your arse!’ (And no, I haven’t made that up, so you can see why I’d want to tell them about it.) Then I realised it had happened a least a couple of years previously, but our tendency to forward telescope the salient events means that – without wanting to mislead – I could have easily given the wrong information. If everyone else did this too, crime figures would appear higher than they really are.