4 Explanations for Why We Forget

Consider how often you find yourself forgetting something important. You might forget the name of someone from your past, a word you want to use, or the date of your best friend's birthday. Forgetting is a common problem that can have both minor and serious consequences. Why and how do we forget information? One of today's best-known memory researchers, Elizabeth Loftus, has identified four major reasons why people forget: retrieval failure, interference, failure to store, and motivated forgetting.


Retrieval Failure

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Have you ever felt like a piece of information has just vanished from your memory? Or maybe you know that it's there, but you just can't seem to find it. The inability to retrieve a memory is one of the most common causes of forgetting.

So why are we often unable to retrieve information from memory? One possible explanation of retrieval failure is known as decay theory. According to this theory, a memory trace is created every time a new theory is formed. Decay theory suggests that over time, these memory traces begin to fade and disappear. If​ the information is not retrieved and rehearsed, it will eventually be lost.

One problem with this theory, however, is that research has demonstrated that even memories which have not been rehearsed or remembered are remarkably stable in long-term memory.



Interference theory
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Another theory known as interference theory suggests that some memories compete and interfere with other memories. When information is very similar to other information that was previously stored in memory, interference is more likely to occur.

There are two basic types of interference:

  • Proactive interference is when an old memory makes it more difficult or impossible to remember a new memory.
  • Retroactive interference occurs when new information interferes with your ability to remember previously learned information.

While interference can make it difficult to remember some things, there are things you can do to minimize its effects. Rehearsing new information is often the most effective approach. By essentially overlearning new things, it is less likely that old information will compete with new.


Failure to Store

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Sometimes, losing information has less to do with forgetting and more to do with the fact that it never made it into long-term memory in the first place. Encoding failures sometimes prevent information from entering long-term memory.

In one well-known experiment, researchers asked participants to identify the correct U.S. penny out of a group of drawings of incorrect pennies. Try doing this experiment yourself by attempting to draw a penny from memory, and then compare your results to an actual penny.

How well did you do? Chances are that you were able to remember the shape and color, but you probably forgot other minor details. The reason for this is that only details necessary for distinguishing pennies from other coins were encoded into your long-term memory. Identifying a penny does not require knowing the exact image or words found on the coin. Because this information is not really needed, you have likely never taken the time to memorize it and commit it to memory.


Motivated Forgetting

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Sometimes we may actively work to forget memories, especially those of traumatic or disturbing events or experiences. Painful memories can be upsetting and anxiety-provoking, so there are times we may desire to eliminate them. The two basic forms of motivated forgetting are suppression, which is a conscious form of forgetting, and repression, an unconscious form of forgetting.

However, the concept of repressed memories is not universally accepted by all psychologists. One of the problems with repressed memories is that it is difficult, if not impossible, to scientifically study whether or not a memory has been repressed.

Also note that mental activities such as rehearsal and remembering are important ways of strengthening memory, and memories of painful or traumatic life events are far less likely to be remembered, discussed, or rehearsed.

A Word From Verywell

While forgetting is not something that you can avoid, understanding the reasons for it can be useful. We may forget for a variety of reasons and in some cases, a number of factors may influence why we struggle to recall information and experiences. Understanding some of the factors that influence forgetting can make it easier to put memory-improvement strategies into practice.

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