The Seven Sins of Memory: How the Mind Forgets and Remembers. By Daniel L. Schacter. Boston: Houghton Mifflin, 2001. 272 pages. $25.

Reviewed by Margaret Black

If forgetting people’s names and habitually losing your car keys has you scarfing down Gingko biloba to stimulate your memory, this book is definitely for you.

First, it’s very reassuring. Author Daniel Schacter is identified on the book’s cover as Chair of Harvard University’s Department of Psychology, so you’re in the hands of a certified expert, right? But more to the point, the author immediately announces that none of the seven major categories of memory failure are the least unusual. They happen all the time every day to everyone. Even young people, with lots of blood pumping through their shiny new brains, suffer from all of them. If healthy older people tend to endure certain kinds of memory loss or make certain kinds of memory mistake, it’s sometimes because they have such rich general memory banks. The generalizations made possible by years of accumulated memories can seriously interfere with the retrieval of exact, specific information. Obviously Alzheimer’s and other tragic memory pathologies exist, and older people are more likely to suffer them or to experience benign memory problems. But old people should take heart. Young children have disproportionately frequent occurrences of certain memory errors.

The book is also very clearly written and it’s highly entertaining. Although Schacter draws heavily on formal psychological studies, he also takes many examples from familiar news stories, sports, literature, and movies. He’s right there with John Doe #2 in Oklahoma City and at the McMartin Little Rascals daycare case. He examines Nietzsche’s plagiarism in Also sprach Zarathustra. He tells a charming story of a psychologist feverishly writing down a wonderfully catchy tune that woke him up one night, only to discover late the next day that it was The Blue Danube Waltz.

Schacter begins with crisp descriptions of what he calls the seven “sins” of memory. The first sin is transience. This is the phenomenon of most events quickly fading from your mind or disappearing from memory altogether. You can imagine that it would be totally overwhelming to remember everything with equal vividness, but transience can be extraordinarily annoying when you suddenly need to recall an occasion or encounter, and your brain has long since ceased to cruise those circuits or has overwritten them altogether.

The second sin is absent-mindedness. These memory lapses usually occur because you were distracted when you needed to be encoding the memory. You forget where you parked the car, for example, because you were working out your plans for world domination when you pulled into Price Chopper. The necessary human capacity to multitask requires that you operate on automatic pilot much of the time, but when you do something out of your regular routine, like putting your coffee mug on the bookshelf while looking up “spandrel,” you may not be able to locate the mug when you next want a sip of coffee.

The third sin, blocking, is the intensely embarrassing social problem where you can’t remember the name of the person you had an intense conversation with at the party a week ago. Remembering proper names is problematic because their sounds do not call to mind any meaningful picture or other memory value. You can remember that a person is a baker because you have mental images that reinforce your concept of the occupation, but you won’t remember the proper name Baker. It is also blocking when you are just about to say a word or refer to a concept and suddenly you lose it completely. You have the sense that the word’s right there, literally in your mouth. The experience is so universal that languages worldwide have expressions almost exactly the same as “on the tip of your tongue.”

These first three problems Schacter called sins of omission because for different reasons you have not properly encoded the memory or reinforced it once it was encoded. The remaining four problems he calls sins of commission because you actively bring the problem about. With three of them you override a true memory. Misattribution is the memory sin that plagues eyewitness reports. This is where you apply the wrong source to a memory or rearrange the elements in the memory. Suggestibility occurs when something you are told causes you to revise or alter your memory. You believe you saw a film of an accident because someone told you that such a film exists and you did see still photographs of the accident on TV. Children are particularly vulnerable to suggestibility. However, bias, where you put a particular experience into a pre-existing category rather than identifying its unique characteristics, is a particular a fault of older people. Finally, there is persistence. In its most benign form, this is the replaying of a pop tune in your head all day. On a more serious level, it’s when you keep reliving an experience, usually a bad one like a car wreck or a rape, over and over again.

Schacter then talks about the actual brain activity that occurs during each particular kind of memory lapse. Here again, the clarity of the author’s writing, particularly about complex details, turns what might be a exhausting slog through a technical swamp into an exhilarating hike along a mountain ridge. Research into the operations of the human brain has only recently become possible, and it’s fascinating to literally see remembering as it happens. You learn, for example, that brains not only encode different kind of memories differently, but the circuitry makes each kind of memory error in a distinct way as well.

If as a reader you want help with your own faulty memory—and this will surely be why many people read the book—Schacter provides suggestions for how to improve each particular kind of memory or moderate its ill effects.

Before concluding, the author comes to the defense of the seven memory sins. Each appears, he says, to serve an important function. Some of them seem to have been adaptations selected over evolutionary time. What you regard as failure and deterioration may also have proven an effective strategy in the quest for survival. For the greater good of the species, memory losses and mistakes may be a trade-off you simply have to accommodate.