Looking at the past through a telescope: adults postdated their earliest childhood memories

ABSTRACT

Our previous studies have consistently shown a telescoping error in children’s dating of earliest childhood memories. Preschool children through adolescents systematically date their earliest memories at older ages, in comparison with the age estimates provided by their parents or by themselves previously. In the current study, we examined the dating of earliest childhood memories in two samples of college adults and collected independent age estimates from their parents. Consistent with our findings with children, adults significantly postdated their earlier memories by approximately 12 months (Study 1) and 6 months (Study 2). The actual age of earliest memories was 2.5 years after adjusted for telescoping errors, 1 year earlier than what is commonly believed at 3.5 years. These findings challenge commonly held theoretical assumptions about childhood amnesia and highlight critical methodological issues in the study of childhood memory.     

Creating false memories for events that occurred before versus after the offset of childhood amnesia

We examined whether false images and memories for childhood events are more likely when the event supposedly took place during the period of childhood amnesia. Over three interviews, participants recalled six events: five true and one false. Some participants were told that the false event happened when they were 2 years old (Age 2 group), while others were told that it happened when they were 10 years old (Age 10 group). We compared participants’ reports of the false event to their reports of a true event from the same age. Consistent with prior research on childhood amnesia, participants in the Age 10 group were more likely than participants in the Age 2 group to remember their true event and they reported more information about it. Participants in the Age 2 group, on the other hand, were more likely to develop false images and memories than participants in the Age 10 group. Furthermore, once a false image or memory developed, there were no age-related differences in the amount of information participants reported about the false event. We conclude that childhood amnesia increases our susceptibility to false suggestion, thus our results have implications for court cases where early memories are at issue.     

Creating false memories for events that occurred before versus after the offset of childhood amnesia

We examined whether false images and memories for childhood events are more likely when the event supposedly took place during the period of childhood amnesia. Over three interviews, participants recalled six events: five true and one false. Some participants were told that the false event happened when they were 2 years old (Age 2 group), while others were told that it happened when they were 10 years old (Age 10 group). We compared participants' reports of the false event to their reports of a true event from the same age. Consistent with prior research on childhood amnesia, participants in the Age 10 group were more likely than participants in the Age 2 group to remember their true event and they reported more information about it. Participants in the Age 2 group, on the other hand, were more likely to develop false images and memories than participants in the Age 10 group. Furthermore, once a false image or memory developed, there were no age-related differences in the amount of information participants reported about the false event. We conclude that childhood amnesia increases our susceptibility to false suggestion, thus our results have implications for court cases where early memories are at issue.     

True photographs and false memories

Abstract— Some trauma-memory-oriented psychotherapists advise clients to review old family photo albums to cue suspected "repressed" memories of childhood sexual abuse. Old photos might cue long-forgotten memories, but when combined with other suggestive influences they might also contribute to false memories. We asked 45 undergraduates to work at remembering three school-related childhood events (two true events provided by parents and one pseudoevent). By random assignment, 23 subjects were also given their school classes' group photos from the years of the to-be-recalled events as memory cues. As predicted, the rate of false-memory reports was dramatically higher in the photo condition than in the no-photo condition. Indeed, the rate of false-memory reports in the photo condition was substantially higher than the rate in any previously published study.     

The distribution of early childhood memories

The quantitative distribution of autobiographical memories for the first decade of life is described. The distribution, based on over 11,000 autobiographical memories from age 10 and younger from published studies, is nearly identical for males and females, for participants of different ages, and for different methods of collecting data, including using words to cue memories from anywhere in the lifespan or from just the childhood years, exhaustive listing of all early memories, and interviews.     

The wane of childhood amnesia for autobiographical and public event memories

We modified Bruce, Dolan, and Phillips-Grant's (2000) threshold procedure for determining the wane of childhood amnesia. In two experiments, undergraduates labelled childhood events (e.g., your first permanent tooth came in) as know or recollect memories and estimated their age at the event's occurrence. In both studies the estimated transition from mostly know memories to mostly recollect memories was roughly 4.7 years. This transition estimate was replicated in a sample of adults (ages 24-65 years) with both Bruce et al.'s event-generation task and the Experiment 1a questionnaire. By contrast, in two experiments a transition estimate of roughly 6 years was found for undergraduates' memories of public events (e.g., the Challenger explosion). The wane of childhood amnesia appears to occur around 4.7 years.     

The distribution of early childhood memories

The quantitative distribution of autobiographical memories for the first decade of life is described. The distribution, based on over 11,000 autobiographical memories from age 10 and younger from published studies, is nearly identical for males and females, for participants of different ages, and for different methods of collecting data, including using words to cue memories from anywhere in the lifespan or from just the childhood years, exhaustive listing of all early memories, and interviews.     

Using cue words to investigate the distribution of autobiographical memories in childhood

The cue-word technique is frequently used with adults to examine the distribution of autobiographical memories across the life span. Such studies demonstrate childhood amnesia: a paucity of memories of events from the first 3(1/2) years of life, and a gradually increasing number of memories from age 3 to age 7. The pattern is remarkable in light of findings of autobiographical competence among children in the period of life eventually obscured by this amnesia. In the present study, we modified the cue-word task for use with school-age children. Seven- to 10-year-olds successfully generated and dated memories of past events. Girls provided more complete narratives than boys. Across the sample, the resulting distribution of memories was better fit by an exponential than by a power function, implying that early memories may not consolidate and instead remain vulnerable to interference. Implications for explanations of childhood amnesia are discussed.     

Imagination equally influences false memories of high and low plausibility events

To examine the effects of event plausibility on people's false beliefs and memories for imagined childhood events, subjects took part in a three‐stage procedure. First, subjects rated how confident they were that they had experienced certain childhood events. They also rated their memories of the events. Second, 1 week later, subjects imagined one high, one moderate and one low plausibility event. Third, 1 week later (and 2 weeks after their initial ratings), subjects rated their confidence and memory a second time. Imagining the events made subjects more confident that they were genuine experiences and gave subjects clearer and more complete memories. Plausibility did not affect subjects' confidence but it did affect their memories. Subjects developed clearer and more complete memories for high, followed by moderate, followed by low plausibility events regardless of whether those events were imagined. We use a nested model of plausibility, belief and memory to discuss our findings. Copyright © 2008 John Wiley & Sons, Ltd.     

The wane of childhood amnesia for autobiographical and public event memories

We modified Bruce, Dolan, and Phillips-Grant's (2000) threshold procedure for determining the wane of childhood amnesia. In two experiments, undergraduates labelled childhood events (e.g., your first permanent tooth came in) as know or recollect memories and estimated their age at the event's occurrence. In both studies the estimated transition from mostly know memories to mostly recollect memories was roughly 4.7 years. This transition estimate was replicated in a sample of adults (ages 24-65 years) with both Bruce et al.'s event-generation task and the Experiment 1a questionnaire. By contrast, in two experiments a transition estimate of roughly 6 years was found for undergraduates' memories of public events (e.g., the Challenger explosion). The wane of childhood amnesia appears to occur around 4.7 years.     

Remembering Early Childhood: How Much, How, and Why (or Why Not)

In this article, we consider recent research on three questions about people's memories for their early childhood: whether childhood amnesia is a real phenomenon, whether implicit memories survive when explicit memories do not, and why early episodic memories are sketchy. The research leads us to form three conclusions. First, we argue that childhood amnesia is a real phenomenon, as long as the term is defined clearly. Specifically, people are able to recall parts of their lives from the period between ages 2 and 5 years, but they recall less from that period than from other periods. Second, we conclude that implicit memories from early childhood may be evident even when explicit memories are not, a finding that suggests early experience may affect behavior in ways that people do not consciously recognize. Third, we argue that although young children are well known to be wonderfully efficient learners of semantic information, they have difficulty in either encoding or retrieving the interlinked aspects of events that lend them their autobiographical character. Although more evidence is needed, the relative lack of episodic memories of early childhood may be linked to maturation of prefrontal cortex.     

Mood and memories of parental rearing styles: A comparison of mood effects on questionnaire-cued and free recall of autobiographical memories

The relationship between memories of childhood experiences (e.g., adverse parenting) and adult depression often found raises questions of interpretation. On the one hand, both laboratory studies and clinicians' experiences suggest that subjects in a depressed mood frequently show a negative bias in perceptions and memories. Negative childhood memories in depressed persons might, therefore, be interpreted as epiphenomena of depressed mood instead of etiological factors. On the other hand, memories of childhood experiences seem remarkably stable across changes in depressed mood, especially when memories are elicited by means of standardized questionnaires. In the mood and memory literature several explanations for this stability are offered. For one thing, highly structured cues to elicit memories (such as in questionnaires) are hypothesized to be less susceptible to mood bias than unstructured memory cues (such as in free recall procedures). On the other hand, resource allocation theorists suggest that childhood memories, being well established and rehearsed, are relatively impervious to mood bias no matter how they are elicited. In this study we examined whether different methods of eliciting childhood memories (i.e., free recall and questionnaire-cued) are differentially susceptible to mood bias. To this aim, we used a mood induction procedure to induce depressed, neutral, and elated mood and assessed childhood memories both before and after the mood induction using both questionnaires and free recall to elicit memories. Results suggested that memories elicited by means of free recall as well as by means of questionnaire-cued recall were susceptible to depressed and elated mood bias. The implications for research addressing the link between childhood experiences and depression are discussed.     

Fragment memories mark the end of childhood amnesia

Adults described and dated two kinds of first remembrances: a personal event memory (the recollection of a personal episode that had occurred at some time in some place) and a memory fragment (an isolated memory moment having no event context and remembered, perhaps, as an image, a behavior, or an emotion). First fragment memories were judged to have originated substantially earlier in life than first event memories--approximately 3 1/3 years of age for first fragment memories versus roughly 4 years of age for first event memories. We conclude that the end of childhood amnesia is marked not by our earliest episodic memories, but by the earliest remembered fragments of childhood experiences.     

Repression and the inaccessibility of affective memories

The fundamental assumption that repression involves an inaccessibility to affective memories has not been directly addressed in empirical research. In the present study we examined three groups of subjects (repressors, low anxious, and high anxious) under six conditions of recall (general, happy, sad, anger, fear, and wonder). Subjects were asked to recall personal experiences from childhood and to rate their current mood and the affective intensity of the memories. The results indicated that repressors recalled significantly fewer negative memories than did low-anxious and high-anxious subjects and, furthermore, that they were substantially older at the time of the earliest negative memory recalled. Compared with low-anxious subjects, repressors also recalled fewer positive affective memories as well. This pattern of findings is consistent with the hypothesis that repression involves an inaccessibility to negative emotional memories and indicates further that repression is associated in some way with the suppression or inhibition of emotional experiences in general. The concept of repression as a process involving limited access to negative affective memories appears to be valid.     

Childhood amnesia: Empirical evidence for a two-stage phenomenon

The term childhood amnesia refers to the inability of adults to remember events from their infancy and early childhood. If we plot the number of memories that adults can recall as a function of age during childhood, the number of memories reported increases gradually as a function of age. Typically, this finding has been used to argue that gradual changes in memory development contribute to a gradual decline in childhood amnesia during the preschool period. Alternatively, it is possible that pooling data across participants has obscured more abrupt, stage-like changes in the remission of childhood amnesia. In the present study we examined the number and distribution of childhood memories for individual participants. Six adults were repeatedly interviewed about their childhood memories. We found that the distribution of adults' early childhood memories may be less continuous than pooled data suggest. This finding has important implications for current explanations of childhood amnesia.     

Imagination and memory: Does imagining implausible events lead to false autobiographical memories?

Previous studies have reported that imagination can induce false autobiographical memories. This finding has been used to suggest that psychotherapists who have clients imagine suspected repressed memories of childhood sexual abuse may, in fact, be inducing false memories for the imagined events. In this study, at Time 1 and then, 2 weeks later, at Time 2, 145 subjects rated each of 20 events on the Life Events Inventory as to whether each had occurred to them in childhood. One week after Time 1, the subjects were told that 2 target events were plausible and 2 were implausible. They were then asked to imagine 1 plausible and 1 implausible target event. Plausibility and imagining interacted to affect occurrence ratings; whereas imagining plausible events increased the change in occurrence ratings, imagining implausible events had no effect on occurrence ratings.     

A picture is worth a thousand lies: Using false photographs to create false childhood memories

Because image-enhancing technology is readily available, people are frequently exposed to doctored images. However, in prior research on how adults can be led to report false childhood memories, subjects have typically been exposed to personalized and detailed narratives describing false events. Instead, we exposed 20 subjects to a false childhood event via a fake photograph and imagery instructions. Over three interviews, subjects thought about a photograph showing them on a hot air balloon ride and tried to recall the event by using guided-imagery exercises. Fifty percent of the subjects created complete or partial false memories. The results bear on ways in which false memories can be created and also have practical implications for those involved in clinical and legal settings.     

Childhood amnesia: Empirical evidence for a two-stage phenomenon

The term childhood amnesia refers to the inability of adults to remember events from their infancy and early childhood. If we plot the number of memories that adults can recall as a function of age during childhood, the number of memories reported increases gradually as a function of age. Typically, this finding has been used to argue that gradual changes in memory development contribute to a gradual decline in childhood amnesia during the preschool period. Alternatively, it is possible that pooling data across participants has obscured more abrupt, stage-like changes in the remission of childhood amnesia. In the present study we examined the number and distribution of childhood memories for individual participants. Six adults were repeatedly interviewed about their childhood memories. We found that the distribution of adults' early childhood memories may be less continuous than pooled data suggest. This finding has important implications for current explanations of childhood amnesia.