"I have done it," says my memory. "I cannot have done it," says my pride, refusing to budge. In the end, my memory yields.
-- Friedrich Nietzsche
In memory everything seems to happen to music.
-- Tennessee Williams
Aug. 17, 2007 - Why do we remember things we'd rather forget? Emotion is the culprit, researchers find.
There are some things -- perhaps many things -- each of us would just as soon forget. Psychologists have proven that it's possible to intentionally forget things. So why can't we forget these things?
That's the question explored by University of North Carolina psychologists B. Keith Payne, PhD, and Elizabeth Corrigan.
You really can't simply erase memories from your mind, Payne and Corrigan note. But you can keep yourself from remembering things -- some things -- by using two simple strategies. First, you isolate the thing you want to forget from other memories. And then, if the memory tries to emerge, you block it.
That's very helpful when you want to keep the memory of where you parked yesterday from interfering with the memory of where you parked today. It might also be helpful if it worked to forget a painful or embarrassing event. But for some reason, that almost never works.
Exactly what makes such memories hard to forget? Emotion, theorized Payne and Corrigan. To prove it, they had 218 college students study two sets of pictures. There were 32 emotionally stirring pictures -- half pleasant and half unpleasant -- and 32 emotionally neutral pictures.
Students were told to study the first set of pictures. Half of the students were then told to forget the first set, and remember just the second set. The other students were told to remember both sets of pictures. Then both groups were asked to recall all of the pictures, regardless of what they'd been told before.
In earlier studies using word lists, researchers showed that people easily forgot the first list of items. And when they did, they were better at remembering the second list of items than those who tried to remember both lists. This is because the "forgetters" minds were less cluttered by the first list.
Payne and Corrigan found that their students were good at forgetting neutral pictures. But they did not manage to forget the emotionally stirring pictures, regardless of whether they were pleasant or unpleasant.
"Emotional memories were persistent, loitering even when they were asked to leave," Payne and Corrigan conclude. "The painful or unhappy memories people would most like to leave behind may be the ones that are most difficult to dislodge."
The researchers suggest that emotion makes intentional forgetting much more difficult. It's hard to isolate emotionally charged memories from other memories. And it's hard to suppress memories that are bright with emotion.
"Even a relatively mild emotional reaction can undermine intentional forgetting," Payne and Corrigan conclude.
The study appears in the September issue of the Journal of Experimental Social Psychology.