Verified by 
As the last couple of posts have shown, there can be plenty of reasons for maintaining a healthy skepticism about the veracity of childhood memories. As the slippery workings of memory become obvious to us, there are many ways in which we can begin to doubt memories which previously convinced us. We may discover that the remembered events actually happened to someone else, or we may hear a differing account which makes us appreciate how much our own memory is the product of various kinds of memory distortion. Which might make us wonder: are the memories in which we no longer believe any different in quality to our 'real' ones?
In the first scientific study of ‘nonbelieved memories', a team of researchers in the UK began with anecdotal observations that people do not stop experiencing memories as memories just because they have reason to doubt them1. For example, one respondent had a vivid memory of Santa Claus climbing down the chimney, even though, for obvious reasons, she had stopped believing the memory many years before.
The researchers went on to screen large numbers of undergraduate psychology students at two British universities, asking about nonbelieved memories and following up nearly a hundred students who reported having them. Those students who took part were also asked to produce a believed memory from around the same time period, along with an event which was believed to have occurred but which was not actually remembered. Participants were asked to rate the memories on various phenomenological characteristics, such as the extent to which they felt that they were really travelling back in time, and the memory's vividness, emotional intensity, and importance for the self.
The first finding was that nonbelieved memories were much more frequent than the researchers had predicted. More than twenty percent of the students initially screened reported a nonbelieved memory. Based on the dates given by the participants themselves, the nonbelieved events occurred primarily in middle childhood, and participants mostly ceased to believe them in adolescence. The most common reason for ceasing to believe in the memory was that someone had told the rememberer that it was incorrect. Only a small proportion of these cases involved disputed ownership (such as ceasing to believe the memory because of finding out that another sibling had actually experienced the event). Other reasons given were implausibility (as in the Santa Claus case) and lack of confirmatory evidence.
The researchers then had three categories of memory to compare: believed, nonbelieved, and believed-but-not-remembered. Nonbelieved memories showed no differences from believed memories on several variables, such as visual and tactile qualities, clarity, emotional intensity and richness, coherence, and mental time-travel. (All these ratings were lower for the believed-but-not-remembered events.) On other characteristics (such as auditory, smell and taste qualities, positive feelings and event significance), believed memories produced stronger ratings than either of the other two categories. As far as vividness was concerned, nonbelieved memories lay somewhere between believed memories and events that were believed but not remembered. One quality, strength of negative emotions, was particularly characteristic of nonbelieved memories.
The researchers conclude that nonbelieved memories are similar to ordinary ‘true' memories in many key respects. In their words,
Both believed memories and nonbelieved memories enabled participants to travel back in time mentally and relive the event, reexperience the same intense emotions, clearly recall visual and other perceptual details, and form a clear idea of where objects and people were in the original event. Both types of memory were experienced as a single, unitary, and coherent episode. These data speak to the continued power and compelling nature of these mental representations, regardless of the memory's credibility. (p. 1339)
Findings such as these confirm that we can remember things that we don't believe actually happened, and vice versa. It is not necessary to believe that an event took place in order for us to experience it as a memory. The study also gives some clues to why we might cease to believe in memories in certain cases. Nonbelieved memories were associated with fewer positive feelings, suggesting that representations which feel less good to the rememberer might be more easily challenged. But without research which follows the changes in belief as they happen, it is impossible to know for sure whether these differences are a cause or an effect of the challenge to the memory's veracity.
The researchers also point out that it is possible that some memories are incorrectly rejected, or 'disowned', for reasons other than their truthfulness—perhaps because they don't fit with the individual's view of the self. Again, without being able to study the remembered events as they happen, it's hard to know (except in the case of extreme implausibility) whether these rejections are accurate or not. But even some impossible events are ‘remembered' by some of us. In addition to remembering seeing Santa Claus, a few respondents recalled seeing live dinosaurs and monsters, and having flown unaided. Whatever it is that makes a memory, it is only partly connected to the possibility that it could actually have happened.
1 Mazzoni, G., Scoboria, A., & Harvey, L. (2010). Nonbelieved memories. Psychological Science, 21, 1334-1340.
