Does Confidence in Your Memory Mean That You Are Correct?


The accuracy of an eyewitness’ memory is open to question. 

Confidence in one’s memory is generally believed to be a sign of memory accuracy, but this is not always the case. Some studies have shown a high correlation between confidence and accuracy, while others have shown little to no correlation.

New experimental research by Roediger & DeSoto (2014), published in the journal Memory, has examined the relationship between confidence and memory accuracy using a word recognition memory paradigm.

In short, the study shows that very confident people tend to be more inaccurate, compared to less confident people, when they distinguish between strongly related objects.

Now to the procedure of the study:

  • First, subjects were shown 150 words within 10 different categories, e.g a bird category. Some words were more dominant than others, e.g. eagle is more dominant than flamingo in a bird category
  • The subjects were then distracted for five minutes to make recall more difficult. After the distraction, they were presented with 300 words, some familiar (old) words and some new ones (lures). The lures were either unrelated, strongly or weakly related to the words that they were shown at first
  • Now the subjects were told to judge whether the words were new or old. After having made this old/new judgment, they were asked to rate their confidence in their judgement on a scale from 0  to 100

In sum, the research shows that people who are more confident in their memory also tend to be more accurate. However, this finding was only true for weakly related or unrelated lures.

Technically, the researchers found a negative correlation between confidence and accuracy for strongly related lures. For strongly related lures, subjects who were more confident were less accurate than subjects who were less confident. That is an interesting finding since it is counterintuitive. For weakly related lures, there was a modest positive correlation between confidence and accuracy.

In other words, when people are shown unrelated lures, compared to strongly related lures, they make more accurate judgments. This makes sense in that it is easier to distinguish objects that are weakly related to each other compared to objets that are strongly related. The authors emphasize that these findings have implications for eyewitness memory situations:

“… The greater the similarity between a person in a line-up and the actual suspect, the more likely (all else being equal) that a false identification will occur with high confidence.”

They continue:

“Although the point seems obvious, we can find few experiments that actually demonstrate it, perhaps because confidence ratings are not generally taken in eyewitness research.”

Photo: Isaac Leedom 
  • Memories are also very easily implanted. If a person chooses that wrong person in a lineup with very high confidence, they’re likely to continue to believe that that person is the correct choice.
    One of my professors in college had done his thesis on memory implantation. He wrote synopses of 3 actual events and one made up event concerning his family. He then quizzed each of his family members on each of the events, asking them to supply as many details that they remembered about the events in question. All but one of his family members “remembered” the false event, and were very confident in the details they “remembered”, even though the false event never actually occurred.
    If someone is primed to believe that an event or a detail about an event is true, it doesn’t matter whether it is, they’ll continue to believe very strongly in the accuracy of their false memory. And the sad thing is, juries respond more positively to people who are more certain of the details they provide than to people who are the slightest bit unsure. A person may very strongly believe in their memory, but that doesn’t make their recollection of events any more correct.

    • Hi Typhany,
      Thanks for your comment.
      That is a nice example of how our memory plays tricks with us. I’ve read quite a few examples of how false memories can be implanted into our memory, and as you say, we must be aware of this dilemma, especially when the jury is involved. The must interesting thing about this piece of research is that the most confident people also tend to be more inaccurate when they distinguish between strongly related objects. So one’s confidence is not always an indicant of accuracy. To me, it seems counterintuitive, and that is reason enough to pay extra attention to it so we don’t take things for granted.

    • T.M. Merremont

      This recalls a question I have regarding people who are not as bright as they think. There is a psychological study presented by two researchers in, I believe, the late 1970’s about people who are convinced that they are smarter than they really are, and often present mistaken and ill considered views with assurance and confidence. They said that people who were actually bright were more hesitant to put forward important opinions without careful consideration. Can someone please give me the name of this study, which, as I remember, was named after these two authors with the usual hyphen between their surnames. My email is