HARVARD GAZETTE ARCHIVES

Elizabeth Kensinger shows off her collection of Red Sox and Yankees wear. At right is her collection of Red Sox and Yankees fan brain scans. Her research shows that fans' negative memories of losing are more accurate than their positive memories of winning. (Staff photo Jon Chase/Harvard News Office)

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."

9/11 and combat memories

The Harvard researchers took the relationship between emotion and memory a step further than any previous study. They checked recall for memories related both to the event and to personal details. The way Kensinger describes it, "an event - related detail would be remembering that Sox player David Ortiz hit a two-run homer." A personal detail would be recalling whether you wore jeans with your Yankees T-shirt, or had pepperoni or sausage pizza.

"Memory for event-related details sometimes declines more over time than memory for personal details," Schacter points out.

It turned out that both happy and unhappy fans remembered an equal number of personal details. However, the losing Yankees fans recalled more details related to the game than the Red Sox fans.

"This finding is consistent with prior evidence that negative emotion enhances memories for detail tied to the game itself rather than to personal details," the researchers report in an upcoming issue of the Psychonomic Bulletin and Review. Taken together, the Harvard results show that memory distortion can be less for negative events than for positive or nonemotional happenings.

Not all the experts believe these conclusions hold for all memorable events. Another study found that memories for the terrorist attacks of Sept. 11, 2001, are less likely to be consistently recalled than memories for a personal event like a wedding or a death. "It could be that, at the level of a championship baseball game, negative emotion enhances the ability to recall detailed information, but at higher levels of intensity negative emotions may begin to have a detrimental effect on memory," Schacter points out.

"The emotional intensity experienced on 9/11 is likely to be far greater than that experienced by the vast majority of events in people's lives," Kensinger adds. "Emotional responses to the Sox/Yankees game outcome are more within the range of emotions typically experienced in everyday life."

Off-the-scale emotional arousal would also be experienced by people in combat or in terrorist bombings. "It is difficult (and often impossible) to assess the accuracy of these types of memories," Kensinger comments. "Nevertheless, our data are consistent with the findings that negative experiences, such as combat, are remembered vividly and with tremendous contextual detail."