In an ancient tradition, the seven deadly sins were said to be pride, anger, envy, greed, lust, gluttony and sloth. Note that some are sins of commission (doing what we shouldn't) and others are sins of omission (failure to do what we should). Note also that each is an exaggeration of an essential need, for example, laziness is the extreme of our natural need for rest. In his new book, The Seven Sins of Memory , Harvard psychologist Daniel L. Schacter finds an analogy to the problems of imperfect human memory. Our memory commits the seven sins known as transience, absent-mindedness, blocking, misattribution, suggestibility, bias and persistence. 
Each of memory's sins is a nuisance at times, but it is also necessary for survival and, for that reason, has developed in us through evolution by natural selection. Schacter is a leading authority on the process in which memory traces are recorded and retrieved by the brain, and how they can be lost due to brain damage. That research was the subject of his earlier book Searching for Memory , the winner of several science literature awards. In The Seven Sins of Memory , Schacter writes in plain English without overly technical jargon. Transience is the fading of memory with the passage of time. It's a nuisance when you can't remember the name of a person whom you met last year. Take comfort in the fact that we would be in real trouble if memory wasn't transient. Imagine how confused you would be if a telephone number you looked up a moment ago were exactly as prominent in your mind as every number you have ever seen if your life. Evolution gave our memories transcience because our survival depends on it. When you're about to eat, you want the immediate location of your food to be in the forefront of your thoughts, rather than obscured by equally vivid images of every place in the world where you have ever seen food.
Displaying absent-mindedness, a music student at UCLA drove off with the university's Stradivarius on the roof of his car. The institution recovered the instrument 27 years later. [43] Again, this fault is a gift from evolution because we couldn't function without it. Who could even take a step, or lift a finger, without the ability to put many details of bodily movements on automatic pilot, while we think about other things? [46] In each case, Schacter looks at the latest technology and what it reveals about the brain. For instance, blocking is the inability to retrieve specific information from memory, the tip-of-the-tongue experience. When this occurs, some interesting things show up if we happen to be looking at the frontal lobe of the brain with an MRI (magnetic resonance imaging) or a PET scanner (positron emission tomography). [47] He also considers the latest data on whether certain nutritional supplements can lessen such memory problems. [37] Some of the sins of memory ought to be serious public concerns. Misattribution is false memory. One believes that he or she remembers something which never actually occurred. Most cases are unimportant -- we may feel certain that a movie contains a line which doesn't really appear in the dialogue. Misattribution is a social problem largely because 75,000 criminal trials each year in the U.S. have outcomes that were determined by eyewitness testimony. [92] One type of misattribution is memory conjunction error, that is, imagining that two separate observations were together. [95] Experiments show that people who have seen a list of words containing "multiply" and "aptitude" will later answer in the affirmative when asked whether the list had contained the word "multitude." That seems harmless enough. But now consider the possibility that an innocent person may convicted of a crime, because an eyewitness who saw two people, one with a red beard and another with a large chin, later testified incorrectly in court to having seen the suspect, who has both a red beard and a large chin. It's exactly the same type of error as that which has occurred in the word list experiments, but now it isn't harmless. The chapter on suggestibility required the greatest effort on my part to read and absorb. An example illustrates what we mean by suggestibility : A psychological study was conducted ten months after the news carried the story of a plane crash. The crash itself was never televised. When the researchers asked subjects whether or not the crash was televised, most would recall correctly they had never seen such a broadcast. However, when the researchers asked subjects, "Did you see the television film of the moment when the plane hit the building?", most would reply in the affirmative. In the latter case, the wording of the question implied that the event had been televised. The subjects tended to combine this implication with a visualization of how a plane crash might look, and they thereby produced false memories of having seen the televised footage. [112] Now consider how suggestibility might lead to social problems. Police investigators asking crime witnesses to identify suspects have occasionally hinted to the witnesses that an individual is "already known to be the actual perpetrator" and "we only need you to confirm what we already know." If our memories are as susceptible to suggestion as the research indicates, this practice could be increasing the number of innocent suspects who get convicted of crimes. [115] In the chapter on suggestibility, I would have liked the author to spend a bit more time on the role of advertising, which he discusses briefly. Advertisers spend billions of dollars, not to inform the public about product characteristics, but to control our behavior, to implant in us the belief that we can never lead full and happy lives unless we switch to Brand X. We act subsequently as though we remember having learned that "fact" somewhere. At first, I began to misinterpret the chapter on bias. I failed to note that the term "bias" doesn't merely refer to biased interpretation of the present, such as prejudice. It must be understood in connection with inaccurate recollection of the past. Several types of bias are recognized. Consistency bias is is the error of overstating the extent to which the past and present are similar, and change bias is overestimating the extent to which the past and present are different. Both of those errors can be found in any political debate, as well as in any unhappy marriage. [139-144] Hindsight bias is the false feeling that "I knew it all along." [146] Egocentric bias is error resulting from exaggerating the role of the self, for example, the assumption that one's own memory must be more reliable than some else's. [150] Stereotypical bias involves forming generic memories, not of specific events, but of patterns or gists of experiences. There would have been no bigoted regime of Hitler without bias. However, without some stereotypical bias, we couldn't learn anything at all; indeed, we couldn't even think. We need to generalize the existence of such abstract categories as "tree" or "chair", as distinct from the particular instances of this tree or that chair. Therefore, we can't remove all stereotypes, but should remove those which are unwarranted by facts. In comprehending bias, imperfect recall of the past is the key to understanding distorted recognition of the present. Since we cannot tolerate cognitive dissonance, we may "... fabricate incidents that never happened in order to bring our memories in line with our expectations." [156] Schacter warns of the danger that someone may manipulate society by modifying records of the past, as in Orwell's novel 1984 . [138] The author also provides a three page discussion of the physical basis of bias in the structure of the brain. [157-160] Persistence is, to use Schacter's phrase, "when memory hurts." [165] It is the relatively clear memory of events that we would have preferred to see fade with time. Some people continue to be haunted years or decades after unpleasant experiences. Many combat soldiers have suffered from shell shock and post-traumatic stress disorder (PTSD). [173] In 1986 a pitcher for the California Angels threw a ball that gave the Red Sox a home run which helped them win the World Series, then went into three years of severe depression ending with suicide. [161] Like the other sins of memory, persistence is an evolutionary adaptation. Our survival depended on it when we were hunter-getherers in the forest. People who have frightening memories of being attacked by bears are more likely to be careful to avoid future attacks by bears. Painful or not, evolution favors characteristics which increase the probability that people will survive to reproduce. These seven sins of memory, in this sequence, are the topics of the first seven chapters of the book. Chapter 8, entitled The Seven Sins : Vices or Virtues? revisits the issues raised in the first seven chapters, and then further clarifies the "seemingly contradictory relationship" [206] between the pleasant and unpleasant effects of our faulty memory.
I recommend this book to readers interested in general psychology, social work and self-help practices, as well as the relationship between memory inaccuracies and such social problems as marital discord, racial and ethnic tensions, and erroneous verdicts in the criminal justice system. Hardcover only. 272 pages. 12-page 2-column index. 21 pages of notes as an appendix. 28 page bibliography. A few sketched illustrations; no photographs. |