Memory bias: how selective recall can impact your memories

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How many times have you forgotten where you left your keys? What about your friend who always seems to make up events that never happened? Do you ever struggle to remember someone’s name? Don’t worry—you’re not the only one. Our memory is far from perfect, and the memory bias effect doesn’t help.

A memory bias is a cognitive bias that either impairs or enhances the recall of a memory by altering the content of what we remember. These memory distortions show that memories are not stored as exact replicas of reality. Rather, as cognitive psychologist Gordon Bower explains, our memories are reconstructed during recall. The recall process makes them prone to manipulation and errors.

“Most people, probably, are in doubt about certain matters ascribed to their past. They may have seen them, may have said them, done them, or they may only have dreamed or imagined they did so.” — William James.

The many faces of the memory bias

Technically speaking, the memory bias is a collection of dozens of cognitive biases. Some forms of memory bias can be positive—for instance, protecting us from hurtful memories—while others can be negative, such as when we base our decisions on the most recent rather than the most relevant information.

  1. Rosy retrospection bias. We tend to remember the past as having been better than it really was, which leads to judging the past disproportionately more positively than we judge the present. As the Romans said: memoria praeteritorum bonorum, or “the past is always well remembered.”
  2. Consistency bias. We incorrectly remember our past attitudes and behaviour as resembling our present attitudes and behaviour, so we feel like acting in accordance with our general self-image.
  3. Mood-congruent memory bias. We better recall memories that are consistent with our current mood. For instance, feeling relaxed may bring back relaxing memories; feeling stressed may bring back stressful memories.
  4. Hindsight bias. We have an inclination to consider past events as being predictable—also called the knew-it-all-along bias.
  5. Egocentric bias. We recall the past in a self-serving manner, such as remembering our exam grades as being better than they really were, or remembering a caught fish as bigger than it was.
  6. Availability bias. We often think that memories that come readily to mind are more representative than is actually the case. This is why people tend to overestimate the likelihood of attacks by sharks or the number of lottery winners.
  7. Recency effect. We best remember the most recently presented information. At a trial, evidence presented last may be the clearest in the juror’s memory.
  8. Choice-supportive bias. We remember chosen options as having been better than rejected options.
  9. Fading affect bias. Our emotions associated with unpleasant memories fades more quickly than our emotions associated with pleasant memories.
  10. Confirmation bias. Our tendency to seek and interpret memories in a way that confirms our prior hypotheses or personal beliefs.

These are only a few of the many memory biases the human mind is prone to. Why is our memory so bad? And… Is it really that bad?

The benefits of our faulty memory

Our memory biases are “by-products of otherwise adaptive features of memory, a price we pay for processes and functions that serve us well in many respects,” writes psychologist Daniel Schacter in his book The Seven Sins of Memory.

He explains: “Consider the following experiment. Try to recall an episode from your life that involves a table. What do you remember, and how long did it take to come up with the memory? You probably had little difficulty coming up with a specific incident—perhaps a conversation at the dinner table last night, or a discussion at the conference table this morning. Now imagine that the cue table brought forth all the memories that you have stored away involving a table. There are probably hundreds or thousands of such incidents. What if they all sprung to mind within seconds of considering the cue? A system that operated in this manner would likely result in mass confusion produced by an incessant coming to mind of numerous competing traces. It would be a bit like using an Internet search engine, typing in a word that has many matches in a worldwide database, and then sorting through the thousands of entries that the query elicits. We wouldn’t want a memory system that produces this kind of data overload.”

The limitations of our memory may sometimes feel frustrating, but they are useful trade-offs which allow us to function and survive in the world. Our memory will prioritise information that is recent, frequently used, and likely to be useful—even if sometimes the definition of “useful” may not make rational sense.

In addition, flawed memories may help us better cope with our past and navigate our future. The choice-supportive bias may give us more confidence in our past decisions when there is little we can do to change them. Rosy retrospection may be more helpful than recollecting darker events when we remember a lost one. As Guy de Maupassant puts it: “Our memory is a more perfect world than the universe: it gives back life to those who no longer exist.”

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