Memory is a funny thing. There are times when an important errand slips my mind, but I can’t get that one song out of my head. Distant memories fade with time, but some experiences can haunt people for years. Strangest of all, people can – and frequently do – develop memories of things that never happened at all.
These various peculiarities are the focus of The Seven Sins of Memory: How the Mind Forgets and Remembers. Harvard psychology professor Daniel L. Schacter takes the reader through what he classifies as the seven “sins” of memory. What are these sins? What troubles do they cause us? Could these sins help as well as hurt?
Sin 1: Transience. “Hmmm, that was a while ago, and my memory is a little vague…”
Memories fade as time passes. Recent events stand out sharply in our minds, but details become hazy after a few hours or days pass by. Schacter argues that the memory system tends to forget old information because more recent information – such as where you parked your car this morning, or where you found your last meal – is more likely to be important. From an evolutionary standpoint, it makes little sense for our memories to retain useless information.
Sin 2: Absent-mindedness. “Now where did I put my keys? They were in my hand a moment ago…”
Things slip our minds all the time. The brain can’t focus on too many things at once, so we relegate our attention to the present task, and sometimes end up forgetting things we wanted to do in the future. As any maker of to-do lists knows, the best way to avoid absent-mindedness is to leave reminders to jog our memories at a later time. However, this isn’t as helpful with other types of absent-mindedness, such as when a momentary distraction prevents important information from being encoded in our memories in the first place. For instance, if I’m absorbed in thinking about that to-do list as I walk through the front door, I might never notice where I put the keys.
Sin 3: Blocking. “Oh, what’s that word? It’s on the tip of my tongue!”
We’re all familiar with the maddening sensation of knowing a fact, only to find it just out of reach when we need it. Interestingly, a number of different languages use the phrase “on the tip of the tongue” or similar; the sensation is familiar to people all over the world. Schacter argues that this type of blocking occurs when our mental link between the concept and the word is too tenuous, particularly when we haven’t used the information for a while. More perniciously, blocking can also take the form of repression and even amnesia, when people try to cope with unwanted memories by pushing them away.
Sin 4: Misattribution. “I love J.K. Rowling – The Hunger Games is my favorite series!”
Surprisingly often, people confuse or conflate one entity with another in their recollections. They mix up two people, misremember the context of an event, or forget the source of a piece of information. Misattribution is partly why eyewitness testimony is terribly unreliable. Witnesses might remember a suspect, but mistake when they saw him, where, and what he was doing; this can lead to serious errors, like accusing an innocent bystander of a crime.
Sin 5: Suggestibility. “Brown hair? I don’t think so. Well, maybe. I think he might have … yes, his hair was definitely brown!”
Outside influence can also influence how we remember events, which is another reason not to implicitly trust eyewitness testimony. The slightest leading question can alter what a person remembers, even if the person recognizes it as a false suggestion. People may vividly remember something that is false – even though they previously stated that it never happened.
Sin 6: Bias. “I knew it all along.”
We view the past through the lens of our current knowledge and feelings. Hindsight, as the saying goes, is 20/20, and if we know the outcome of an event, we think it should have been obvious beforehand. In general, we tend to remember our past selves as more similar to our current selves than we actually were; sometimes, however, people mentally exaggerate how unhappy they used to be, making themselves feel more content by comparison.
Sin 7: Persistence. “I can’t get it out of my head!”
Some memories are less subject than usual to the sin of transience, and some experiences will not fade away despite a strong desire to forget. This can range from the benign (can’t get that song out of your head?) to the debilitating (such as PTSD), but unsurprisingly, highly emotional memories tend to be the most persistent.
The sins of memory run the gamut from annoying and commonplace to serious and even ruinous. And yet, at the end of the book, Schacter argues that these qualities are virtues in disguise.
Schacter contends that all of these memory problems – troublesome though they can be – are aspects or byproducts of a memory system that evolved to be efficient. On the whole, humans excel at calling to mind the facts we need, while ignoring those we don’t. What would be the use of devoting energy to forever remember information that we will almost certainly never use again? How could we function if we could not distinguish relevant from irrelevant? We don’t always appreciate it, but our memories serve us well much more often than they let us down.
The Seven Sins of Memory is an interesting exploration of the quirks of memory. Schacter discusses the troubling failures of our memory, and demonstrates that the qualities we think of as flaws are integral to the function of an efficient, powerful system shaped by natural selection.
But I still reserve the right to be annoyed when, for the life of me, I can’t remember where I put my keys.
Schacter, Daniel L. The Seven Sins of Memory: How the Mind Forgets and Remembers.” Boston: Houghton Mifflin Company (2001).