More Questions About Recovered Memories

In their recent study of 90 female patients suffering from trauma-related psychopathology, Dr. Chu et al. noted that “higher dissociative symptoms were correlated with early age at onset of physical and sexual abuse and more frequent sexual abuse.” As in many previous studies, the authors employed the Dissociative Experiences Scale to measure dissociative symptoms. The authors also found that self-reports of partial or complete amnesia for traumatic experiences were related to elevated scores on the Dissociative Experiences Scale. Although the authors did acknowledge that their study relied on patients’ self-reports of dissociation, trauma, and amnesia, my impression is that they underestimated the potential problems that may occur with such measures. Of particular relevance in this context is recent work on the psychological correlates of the Dissociative Experiences Scale (1). This work shows that there is a substantial overlap between the Dissociative Experiences Scale and questionnaires measuring proneness to fantasy (1). As well, there is now solid evidence indicating that high scores on the Dissociative Experiences Scale are closely related to a positive response bias in retrospective self-report scales asking for trivial “bad things” (e.g., “I have been shortchanged in stores”) (2) or even relatively neutral, but highly specific life events (e.g., “I went with my school to Disneyland”) (3). Furthermore, individuals with high scores on the Dissociative Experiences Scale are more receptive to subtle misinformation when answering questions about a narrative that they heard earlier than are individuals scoring low on the scale (4). Similarly, the Dissociative Experiences Scale appears to be a powerful predictor of the vulnerability to developing pseudomemories in response to misleading autobiographical cues (5). Finally, receiving high scores on the Dissociative Experiences Scale correlates positively with reports of supernatural experiences (e.g., telepathy, precognition) (6). Taken together, these findings point to the conclusion that self-reports of individuals scoring high on the Dissociative Experiences Scale may contain exaggerations, distortions, and confabulations. This may explain why at least one study (7) found high scores on the Dissociative Experiences Scale to be related to self-reports of trauma but not to sexual abuse ratings based on hospital records.

In my opinion, then, the findings reported by Dr. Chu and co-workers are difficult to interpret precisely because all their pertinent comparisons and correlations involved individuals with high scores on the Dissociative Experiences Scale (8). Although it should be admitted that it is often impossible to avoid retrospective self-reports, studies like that of Dr. Chu and associates would allow for more convincing conclusions if they included a measure of response bias. With such a measure, it would be possible to statistically correct for the effects of liberal reporting criteria.