Pleasurable experiences are more fun to relive than negative ones, but a new study by psychologists at Harvard University reveals that memories of good times can be less accurate than those of bad times.
Not only that, a person with a positive memory is more likely to be more confident of her or his distorted memory than someone who has a negative memory of the same event.
Take the beating that the Boston Red Sox gave the New York Yankees when the Sox won the American League playoff series in October 2004. That’s the event the Harvard researchers used to probe the effects of emotion on memory.
Elizabeth Kensinger, a postdoctoral fellow, worked with Daniel Schacter, William R. Kenan Jr. Professor of Psychology, to recruit 76 men and women, ages 18-35, who had watched the contest. Some were avid Red Sox fans, some were rabid Yankees fans, and some professed no strong feelings about the outcome. All of them filled out questionnaires within six days of the game, then again after a 23- to 27-week delay. Answers were scored on quantity and consistency of information, confidence in the memory, and its vividness.
Some participants reported a piece of information entirely differently on the two surveys. In those cases, they got a constancy score of zero. Emotion and vividness were rated on a scale of 1 to 7. For emotions, lower numbers indicated negative feelings, higher numbers denoted positive feelings. For example, Red Sox fans gave their memories ratings of 5.5 or higher; Yankees rooters, 2.5 or lower. None of the participants reported a history of psychiatric or nervous disorders.
Studies like this, which compare the emotions and memories associated with well-known happenings, are rare. “To our knowledge, only one prior study examined the effect of positive versus negative emotions on the vividness and accuracy of memory for a public event,” notes Kensinger. The investigators asked men and women about the trial that cleared O.J. Simpson of the murder of his wife. “Those who were happy about the verdict could not discriminate true from false details of the event any better than those unhappy about it,” adds Schacter. “Despite this, the happy group believed they remembered the event more vividly. These results are consistent with laboratory tests showing that positive mood can lead to an increased probability of memory errors.”