The Unreliability of Memory
In a career spanning four decades, [Elizabeth F.] Loftus[www, tw], a psychologist at the University of California, Irvine, has done more than any other researcher to document the unreliability of memory in experimental settings. And she has used what she has learned to testify as an expert witness in hundreds of criminal cases [...] informing juries that memories are pliable and that eyewitness accounts are far from perfect recordings of actual events.
Loftus won funding in 1974 for a proposal to study witness accounts of accidents, and she soon published the first of several influential studies revealing the limitations of eyewitness testimony.1 She showed people film clips of car accidents and asked them to estimate the speed of the cars. The wording of the questions, she found, had a profound effect on the estimates. People who were asked, “How fast were the cars going when they smashed into each other?” gave higher estimates on average than those with whom the verb 'hit' was used. And those who were told that the cars had 'contacted' each other gave the lowest estimates.
Those asked about cars smashing into one another were more than twice as likely as others to report seeing broken glass when asked about the accident a week later, even though there was none in the video. “I realized that these questions were conveying information,” says Loftus. “I began to think of it as a process of memory contamination, and we eventually called it the misinformation effect.”
She went on to publish several other studie2, 3, 4 showing how memories can be contorted, and that the ability of eyewitnesses to identify suspects from photographs can be unreliable. Any description they might hear has the potential to influence who or what they think they saw.
[Later] Loftus began to wonder whether it was possible to fabricate complex, believable memories. “I wanted to see if we could implant a rich memory of an entirely made-up event,” she says. An idea eventually came to her as she drove past a shopping mall.
Working with a student, Jacqueline Pickrell, Loftus recruited 24 people and, with the cooperation of family members, presented them with four detailed accounts of events from their childhood. Three of the incidents had actually taken place, but the fourth — a dramatic account of being lost in a mall — was entirely concocted by Loftus and corroborated by the participants' relatives. One-quarter of the participants claimed to remember the false event.6
Meanwhile, her research has shifted into new controversial waters. Taking on board the lesson that memories can be manufactured, she has been investigating the possibility of using those memories to modify behaviour.9, 10 “We've shown that you can plant a memory of getting sick eating particular foods as a child,” she says, “and we can get people thinking they got sick drinking vodka, so they don't want to drink as much of it later on.”
1. Loftus, E. F. & Palmer, J. C. J. Verb. Learn. Verb. Behav. 13, 585–589 (1974).
2. Loftus, E. F. Cognitive Psychol. 7, 560–572 (1975).
3. Powers, P. A., Andriks, J. L. & Loftus, E. F. J. Appl. Psychol. 64, 339–347 (1979).
4. Loftus, E. F. & Greene, E. Law Hum. Behav. 4, 323–334 (1980).
6. Loftus, E. F. & Pickrell, J. E. Psychiat. Ann. 25, 720–725 (1995).
9. Bernstein, D. M., Morris, E. K., & Loftus, E. F. Soc. Cognition 23, 11–34 (2005).
10. Clifasefi, S. L., Bernstein, D. M., Mantonakis, A. & Loftus, E. F. Acta Psychol. 143, 14–19 (2013).
Quoted on Mon Sep 2nd, 2013