Why You Can't Trust Your Memory (of Anything)
Surprising research into the reliability of "flashbulb memories."
Posted Mar 20, 2016
Do you recall what you were doing when you learned about the terrorist attack on 9/11? Any American old enough to understand the event has a vivid, detailed memory of where they were, who was with them, and how they learned about the event.
I remember the event as if it were yesterday. I was a graduate student at the time, and I was working in the lab. (Where else would a graduate student be?) One of my lab mates rushed in, telling us that a plane had just crashed into the World Trade Center. I was sitting at a computer, and I got onto CNN’s website as my lab mates gathered around.
Then I had to go to the class I was the teaching assistant for. It was a large auditorium, but the professor didn’t lecture that day. Instead, he tried to calm the students down, and he let them share any feelings they had. After that, I went home, where my wife and kids huddled with me on the sofa as we watched the unfolding events on TV. The next day, we went to Walmart to buy an American flag, but they were all sold out.
The memory is so vivid, and I know in my heart that I’ll never forget those events. Yet my psychologist’s brain tells me that most of the details are probably wrong.
In a recent article in the journal Current Directions in Psychological Science, psychologists William Hurst and Elizabeth Phelps review 50 years of research on so-called “flashbulb memories.” These are recollections of emotionally charged events. The term alludes to the experience that these events are seared into memory as if they were flash photos.
Researchers typically conduct studies on flashbulb memories as follows: Immediately after a major national or international event, psychologists interview hundreds of ordinary people about their experience. Key questions include:
- When did you hear about the event?
- Where were you?
- What were you doing?
- How did you find out?
Months or even years later, the researchers contact the respondents again and ask them the same questions. They also ask them to rate the vividness of the memory and how confident they are of its accuracy.
We know that as time passes our memory for ordinary personal events declines in accuracy. What’s more, we also feel that our recollections of those events are fading. That is, we doubt the accuracy of those memories.
But flashbulb memories are different. We remember them as if they’d happened yesterday, even though they took place many years ago. They don’t fade with time but remain vivid and clear in our mind. Further, our confidence about their accuracy stays high, no matter how many years have passed.
Hurst and Phelps point out that researchers can’t really assess the accuracy of memories, even on the first reporting, because they didn’t observe the moment that the memory was formed. Also, several days had already elapsed by the time of the first interview, and we know from other research that that’s plenty of time for a memory to morph. However, what researchers can and do look for is consistency between the first and second telling of the memory.
Half a century of research on flashbulb memories shows us that they don’t remain consistent from one retelling to the next. Just like any other memory, these seemingly vivid recollections shift their shape over time. We forget or misremember details and incorporate information we've only learned afterward into our memory of the original event. All of this occurs despite the fact that our confidence in the accuracy of the memory remains high.
Our personal memories are stories we tell ourselves and share with others. Thus, it comes as no surprise that we reshape our memories of personal events—flashbulb or ordinary—to fit the narrative conventions of our culture. In stories, for example, we expect stormy weather to accompany sinister events and sunny weather for happy endings. When elderly Danes had to recall events from World War II, they remembered the weather on the day of the German invasion as worse than records indicate. Likewise, they recalled better weather on the day of the German withdrawal than was actually the case.
Flashbulb memories aren’t limited to public disasters. Any personal event can become a flashbulb memory if it’s sufficiently charged with meaning and emotion. As Hirst and Phelps point out, post-traumatic stress disorder often includes flashbulb memories of horrific personal experiences. Understanding how flashbulb memories are formed—and how they change over time—may provide researchers with insights into why the disorder occurs and how to treat it.
Further, flashbulb memories aren’t always negative. Events that are flooded with positive emotions can create flashbulb memories as well. For many people, the election of Barack Obama as the first African-American president of the United States was one such powerfully positive flashbulb memory. The fall of the Berlin Wall is another example, one especially meaningful to me, since I’d crossed the wall into East Berlin several years earlier.
Finally, we all have positive flashbulb memories for key personal events in our lives—our wedding day, the birth of our first child. These are vivid memories we’ll cherish for a lifetime—even if we don’t remember them exactly as they occurred.
Hirst, W. & Phelps, E. A. (2016). Flashbulb memories. Current Directions in Psychological Science, 25, 36-41.
David Ludden is the author of The Psychology of Language: An Integrated Approach (SAGE Publications).