The Seven Sins of Memory Insights From Psychology and Cognitive Neuroscience Daniel L. Schacter Harvard University Though often reliable, human memory is also fallible. evident when one contemplates what the various forms of This article examines how and why memory can get us memory make possible in our everyday lives: a sense of into trouble. It is suggested that memory's misdeeds can personal history, knowledge of facts and concepts, and be classified into 7 basic "sins": transience, absent- learning of complex skills. Because of memory's impor- mindedness, blocking, misattribution, suggestibility, tance in everyday life, it is easy to see why Vernon Jordan bias, and persistence. The first three sins involve differ- would be struck by Clinton's "extraordinary memory" and ent types of forgetting, the next three refer to different how that ability would enhance Clinton's prospects as a types of distortions, and the final sin concerns intrusive politician. But, as Clinton professed to have learned during recollections that are difficult to forget. Evidence is his term as President, memory also has a darker, more reviewed concerning each of the 7 sins from relevant fragile side. People may forget events rapidly or gradually, sectors of psychology (cognitive, social, and clinical) distort the past in surprising ways, and sometimes experi- and from cognitive neuroscience studies that include ence intrusive recollections of events that they wish they patients with focal brain damage or make use of recently could forget. developed neuroimaging techniques. Although the 7 sins may appear to reflect flaws in system design, it is argued This darker side of memory has occupied center stage instead that they are by-products of otherwise adaptive in recent scientific, clinical, and popular discussions. As features of memory. most psychologists are acutely aware, a bitter controversy has raged throughout the 1990s concerning the accuracy of recovered memories of childhood sexual abuse (see, for Question: If Vernon Jordan has told us that you have an extraordinary instance, Conway, 1997; Freyd, 1996; Herman, 1992; Kihl- memory, one of the greatest memories he has ever seen in a politician, would that be something you would care to dispute? strom, 1995; Lindsay & Read, 1994; Loftus, 1993; Pope, 1996; Poole, Lindsay, Memon, & Bull, 1995; Read & Clinton: No. I do have a good memory. At least I have had a good memory in my life . It's also—if I could say one thing about my memory—I Lindsay, 1997; Schacter, Norman, & Koutstaal, 1997). have been blessed and advantaged in my life with a good memory. I have Some recovered memories have been corroborated and been shocked and so have members of my family and friends of mine at appear to be accurate, but there are also good reasons to how many things that I have forgotten in the last six years—I think believe that many such memories are inaccurate (e.g., because of the pressure and the pace and the volume of events in a president's life, compounded by the pressure of your four-year inquiry, Lindsay & Read, 1994; Schacter, 1996; J. W. Schooler, and all the other things that have happened. 1994). False memories of childhood sexual abuse are as- sociated with devastating psychological consequences for When President Clinton testified before Kenneth Starr's accusers and their families (Loftus & Ketcham, 1994; grand jury, his numerous lapses of memory prompted in- Pendergrast, 1995). As the debate concerning recovered vestigators to query him about his reputation for prodigious memories has raged, memory researchers have focused recall. The logic implicit in their question, later articulated increasingly on developing experimental paradigms to ex- explicitly by Starr in his own testimony to the House plore illusory or false memories in which people confi- committee investigating impeachment charges, seems dently claim to recollect events that never happened (for clear: How could someone with such a seemingly excep- tional memory forget as much as Clinton did about the details of his encounters with Monica Lewinsky? Starr's lawyers were, to put it mildly, suspicious about the self- Editor's note. Denise C. Park served as action editor for this article. serving aspects of Clinton's failures to recall potentially damning incidents and statements. Although their skepti- Author's note. Preparation of this article was supported by grants from the National Institute on Aging, National Institute of Mental Health, and cism may indeed be warranted, the contrast between Clin- Human Frontiers Science Program. I thank Wilma Koutstaal, Susan ton's reputation for extraordinary memory on the one hand, McGlynn, and Anthony Wagner for useful comments and discussion, and and his claims of sketchy recollections for his encounters I thank Sara Greene and Carrie Racine for help with preparation of the with Lewinsky on the other, also illustrates a fundamental article. duality of memory. Correspondence concerning this article should be addressed to Daniel L. Schacter, Department of Psychology, Harvard University, 33 I have previously referred to this duality as memory's Kirkland Street, Cambridge, MA 02138. Electronic mail may be sent to "fragile power" (Schacter, 1996). The power of memory is [email protected]. 182 March 1999 • American Psychologist Copyright 1999 by the American Psychological Association, Inc. 0003-066X799/S2.00 Vol. 54. No. 3, 182-203 future, and blocking refers to the temporary inaccessibility of information that is stored in memory. The next three sins all involve distortion or inaccuracy. Misattribution in- volves attributing a recollection or idea to the wrong source, suggestibility refers to memories that are implanted as a result of leading questions or comments during at- tempts to recall past experiences, and bias involves retro- spective distortions and unconscious influences that are related to current knowledge and beliefs. The seventh and final sin, persistence, refers to pathological remembrances: information or events that we cannot forget, even though we wish we could. Like the biblical seven deadly sins—pride, anger, envy, greed, gluttony, lust, and sloth—the seven sins of memory occur frequently in human affairs. The biblical sins, however, can also be seen as exaggerations of human traits that are in many respects useful and even necessary for survival. So, too, is the case for the seven sins of Daniel L. memory. As annoying and occasionally dangerous as they Schacter may be, I suggest later in this article that memory's sins Photo by liza should not be viewed as flaws in system design or unfor- HMS Medio Services tunate errors made by Mother Nature during the course of evolution. Instead, the seven sins are more usefully con- ceptualized as by-products of otherwise desirable features of human memory (cf. J. R. Anderson & Schooler, 1991; review and discussion, see Estes, 1997; Roediger, 1996; Bjork & Bjork, 1988). Perhaps paradoxically, then, the Schacter, Norman, & Koutstaal, 1998). seven sins can provide insights into the very operations of Although false memories have been discussed inten- memory that make it such a valuable resource in numerous sively in recent years, forgetting is perhaps the most famil- aspects of our everyday lives. iar of memory's indiscretions. Psychologists and neurosci- entists have studied forgetting ever since Ebbinghaus In the body of this article, I summarize two major (1885) applied experimental methods to the study of mem- types of evidence and ideas concerning each of the seven ory and provided quantitative estimates of forgetting. The sins. First, much of what is known about the seven sins general public, too, has become increasingly concerned comes from work in cognitive, social, and clinical psychol- with forgetting, even prior to the release of Clinton's ogy; I summarize recent research from each of these do- forgetting-filled grand jury testimony. As highlighted by a mains. Second, I consider what we have learned aboui the recent cover story concerning memory in Newsweek (Cow- seven sins from the perspective of contemporary cognitive ley & Underwood, 1998), millions of aging babyboomers neuroscience. During the past 20 years, cognitive neuro- in addition to Clinton are trying to understand why they science analyses of human memory have become increas- now forget more frequently than in the past and what, if ingly influential (for general summaries, see Gabrieli, anything, they can do about it (e.g.. Crook & Adderly, 1998; Gazzaniga, 1995; Schacter. 1992, 1996). The cogni- 1998). tive neuroscience approach has relied heavily on studies of patients with brain lesions that selectively affect particular We are all affected by memory's shortcomings in our forms of memory and, more recently, on studies using everyday Jives, and scientists have studied them for de- functional neuroimaging techniques, such as positron emis- cades. But there have been few attempts to systematically sion tomography (PET) and functional magnetic resonance organize or classify the various ways in which memory can imaging (fMRI). PET and fMRI measure local changes in lead us astray and to assess the state of the scientific hemodynamic responses that are correlated with changes in evidence concerning them. Given the scientific attention neuronal activity: PET is sensitive to changes in blood paid recently to (he fallibility of memory, and the important flow, whereas fMRI is sensitive to oxygenation-level - real-world consequences that are sometimes associated dependent changes