Is when a persons memory of an event changes due to the introduction of misinformation from external sources?

The misinformation effect is the tendency for information received after an event to interfere with one's memory of the original happenings. Research has shown that the introduction of even relatively subtle new information later on can have a dramatic effect on how people remember events they have seen or experienced.

The misinformation effect illustrates how easily memories can be influenced. It also raises concerns about the reliability of memory—particularly when the memories of eyewitnesses are used to determine criminal guilt, referred to as eyewitness testimony. 

The misinformation effect can lead to inaccurate memories and, in some cases, result in the formation of false memories.

What Is the Misinformation Effect?

Psychologist Elizabeth Loftus, who is known for her study of false memories, says, "The misinformation effect refers to the impairment in memory for the past that arises after exposure to misleading information."

The work of Loftus and her colleagues has demonstrated that the questions asked after witnessing an event can actually influence a person's memory of that event. In other words, if a question contains misleading information, it can distort the memory of the event, a phenomenon that psychologists have dubbed "the misinformation effect." 

Misinformation Effect Example

In the famous experiment conducted by Loftus, participants were shown video footage of a traffic accident. After watching the clip, participants were asked a number of questions about what they had observed, much in the same way police officers, accident investigators, and attorneys might question an eyewitness.

One of the questions asked was, "How fast were the cars going when they hit each other?" In some instances, however, a subtle change was made; participants were instead asked how fast the cars were going when they "smashed into" each other. Researchers discovered that using the word "smashed" instead of "hit" could change how the participants remembered the accident.

A week later, the participants were once again asked a series of questions, including "Did you see broken glass?" Most of the participants correctly answered no. But those who had been asked the "smashed" version of the question in the initial interview were more likely to incorrectly believe that they had indeed seen broken glass.

How can such a minor change lead to false memories of the video clip? Experts suggest that this is an example of the misinformation effect at work.

Misinformation Effect Theories

Why does the misinformation effect happen, potentially leading to the formation of false memories? There are a few different theories.

• Blending of memories: One explanation is that the original information and the misleading information presented after the fact get blended together in the person's memory.
• Replacement of memories: Another possibility is that the misleading information actually overwrites the original memory of the event.
• Retrieval of memories: Researchers have also suggested that since the misleading information is more recent in memory, it tends to be easier to retrieve.
• Filling of memory gaps: In some cases, the pertinent data from the original event may never have been encoded into memory in the first place. So, when misleading information is presented, it is incorporated into the mental narrative to fill in these gaps in memory.

Factors Influencing the Misinformation Effect

Research has shown that there are several factors that can contribute to the misinformation effect, making it more likely that event happenings will be distorted and lead to false memories.

• Discussing the event with other witnesses:Talking to other witnesses following an event can distort a person's original memory. Their reports might conflict with the original memory of an event, and the new information might reshape or distort a witness's original memory of the events as they occurred.
• Reading or watching news reports:Reading news stories and watching television reports of an accident or event can also contribute to the misinformation effect. People often forget the original source of information, which means that they might mistakenly believe that a piece of information was something they observed personally when, in reality, it was something they heard in a post-event news report.
• Repeated exposure to misinformation: The more often people are exposed to misleading information, the more likely they are to incorrectly believe that the misinformation was part of the original event.
• The passage of time: If the misleading information is presented some time after the original memory, it is likely to be much more accessible in memory. In these cases, the misleading information is much easier to retrieve, effectively blocking the retrieval of the original, correct information.

How to Reduce the Misinformation Effect

What can prevent intervening information and events from altering memories or even creating false memories? Writing down your memory of an important event immediately after it happens is one strategy that might help minimize the effects.

Keep in mind that even this strategy can introduce subtle errors, and writing these errors down can further cement them in your memory.

Being aware that your memory can be influenced is another helpful and important strategy. While you might have a good memory, understand that everyone is susceptible to the misinformation effect.

That said, susceptibility may be even greater for people with a low need for cognition. Research exploring the misinformation effect paradigm found that individuals with a high cognitive need were better at detecting differences between the original event memory and the misinformation. People with high cognitive need tend to think about ideas and pursue mentally challenging tasks, like puzzles.

How to Distinguish False Memories

Some argue that there is no way to distinguish a false memory from a real one. This creates a challenge not just when trying to remember a particular event, but also in memory research.

If there is video footage of the event, reviewing it can help you decide if your memories are real or if they could be false. It may also be beneficial to consider other people's recollections of the event. If they are all saying the same thing, and it is different than what you remember, the misinformation effect may be at play.

A Word From ​Verywell

The misinformation effect can have a profound impact on our memories, sometimes causing us to believe that false memories are real. Taking the time to write down events after they can occur can help reduce this effect—as long as the events happened as we wrote them down.

Anyone can experience the misinformation effect. However, being aware of this can help you be more alert when trying to recall an event, potentially reducing your susceptibility to the creation of false memories.

Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

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6. Szpitalak M, Polczyk R. Inducing resistance to the misinformation effect by means of reinforced self-affirmation: The importance of positive feedback. PLoS One. 2019;14(1):e0210987. doi:10.1371/journal.pone.0210987

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Additional Reading

By Kendra Cherry
Kendra Cherry, MS, is an author and educational consultant focused on helping students learn about psychology.

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