Third Circuit Finds Expert’s Testimony That Recovered Memories Are No Less Accurate Than Continuous Memories Was Improperly Admitted

January 14, 2025

Federal Rule of Evidence 702 provides that

A witness who is qualified as an expert by knowledge, skill, experience, training, or education may testify in the form of an opinion or otherwise if the proponent demonstrates to the court that it is more likely than not that:

(a) the expert’s scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue;

(b) the testimony is based on sufficient facts or data;

(d) the expert’s opinion reflects a reliable application of the principles and methods to the facts of the case.

Under the federal rules, courts apply Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993), to determine whether expert testimony is sufficiently reliable to be admissible. The recent opinion of the Third Circuit in Cohen v. Cohen, 2025 WL 45704 (3rd Cir. 2025), provides a good example of Rule 702 in action.

In Cohen, “[a] woman sued her father alleging childhood sexual abuse and supported her claims with expert testimony describing the accuracy of ‘recovered” memories.'” Specifically, the plaintiff’s expert, Dr. Hopper testified that

while “memories generally fade,” individuals “typically remember the gist of what happened and some of the most central details.”…And “the phenomena of what are known colloquially as ‘repressed’ and ‘recovered’ memories are well-established facts,” as shown by the inclusion of “dissociative amnesia” in “the field of psychiatry’s ‘diagnostic bible,’ the Diagnostic and Statistical Manual” (“DSM”)….Dr. Hopper stressed that “there is no evidence that recovered memories are less accurate than continuous memories, but there is evidence for no difference in accuracy.”…

[The defendant] moved to exclude Dr. Hopper’s expert report and testimony, arguing in part “that repressed memory is no longer a generally accepted theory among the current scientific community.”

The court denied the motion, prompting the defendant’s appeal. On appeal, the Third Circuit reversed, ruling as follows:

Applying the gatekeeping requirements required for expert testimony, we conclude that Dr. Hopper’s testimony lacked both the reliability and fit required under Rule 702….

While there is no “definitive checklist or test,”…“good grounds” supporting an expert’s testimony include:

(1) whether a method consists of a testable hypothesis; (2) whether the method has been subject to peer review; (3) the known or potential rate of error; (4) the existence and maintenance of standards controlling the technique’s operation; (5) whether the method is generally accepted; (6) the relationship of the technique to methods which have been established to be reliable; (7) the qualifications of the expert witness testifying based on the methodology; and (8) the non-judicial uses to which the method has been put….

Consider Dr. Hopper’s report, in which he points to the DSM’s inclusion of “dissociative amnesia” as evidence that “‘repressed’ and ‘recovered’ memories are well-established facts.”…As Dr. Hopper explained, dissociative amnesia is the “inability to remember important biographical information, auto[-]biographical information, usually of a stressful or traumatic nature that is inconsistent with ordinary forgetting.”…But general acceptance of dissociative amnesia does not establish the same with respect to the accuracy of recovered memories. For “if one argued that the inclusion of dissociative amnesia in [the DSM] demonstrated acceptance of repressed memory, it would be analogous to saying that by recognizing the diagnosis of ‘hoofed mammals,’ one was demonstrating the acceptance of unicorns.”

Also without basis is Dr. Hopper’s claim that “there is no evidence that recovered memories are less accurate than continuous memories, but there is evidence for no difference in accuracy.”…For support, he cited two almost thirty-year-old studies. The 1995 study outlined preliminary evidence to suggest that recovered memories are as consistent as continuous memories when the victim reported the abuse in childhood and afterward underwent a physical examination. But it is unclear when and to what degree Ms. Cohen reported her abuse, and there is no record of a contemporaneous physical examination. The 1996 study found that the same percentage of continuous and recovered memories of abuse had at least one piece of evidence to support their accuracy. And while “experts commonly extrapolate from existing data,” here “there is simply too great an analytical gap between [these studies] and the opinion proffered” by Dr. Hopper that recovered memories are just as accurate as continuous memories….

The probative value of these studies is further weakened by their relatively small sample sizes. Though there is no one-size-fits-all for study sizes under Daubert‘s reliability prong,…the seventeen-person sample in the 1996 study is insufficient. Indeed, the author of the 1995 study, which was more than seven times the size of the 1996 study, cautioned that its “statistical analyses must be considered preliminary” because the study “relied on a small sample.”…

Nor is Dr. Hopper’s testimony that “research over and over again shows that” memories “freely recall[ed]” are “85 to 95 percent accurate” substantially supported by the research he cited….Dr. Hopper did not elaborate on the “research” underpinning his conclusory statement. And despite Ms. Cohen’s efforts to identify studies supporting this claim, Dr. Hopper cited none of them in his report and therefore cannot be credited with relying on them.

Taken together, Dr. Hopper’s testimony was unsupported by “good grounds” that would demonstrate reliability….

An expert’s testimony “fits” the proceedings, if it “will help the trier of fact to understand the evidence or to determine a fact in issue.”…“‘Fit’ is not always obvious, and scientific validity for one purpose is not necessarily scientific validity for other, unrelated purposes.”…“This condition goes primarily to relevance,”…so an expert’s “testimony will be excluded if it is not scientific knowledge for purposes of the case.”…

Dr. Hopper’s testimony that “freely recall[ed]” memories are “85 to 95 percent accurate” does not fit the facts here….Ms. Cohen did not testify that she recalled any memories of abuse because of someone else’s questions. Indeed, she never “remember[ed] an incident of abuse because of something” her therapist said….Rather, Ms. Cohen “would be going about the community” and experience “emotional sensations and physical sensations” that she would then “have to try to figure out.”… But those instances of recollection are not emblematic of “free recall.”

Nor is Dr. Hopper’s general theory of memory repression applicable to this case. He testified that abuse victims repress memories “because to relive [them] is going to evoke emotions that are going to make it harder for [the victim] to connect with and survive with the caregiver.”…But rather than try to “connect with” Mr. Cohen,…Ms. Cohen testified that she was “disgusted and revolted by him,”… and had “hated [her] father since [she] was four years old.”…Indeed, Ms. Cohen “didn’t want to be around [Mr. Cohen],” “didn’t want to spend time with him,” and “would throw horrible tantrums” to avoid being with him….

In sum, Dr. Hopper’s testimony lacked reliability and fit, contravening the requirements of Rule 702. The District Court erred in failing to analyze these core components before admitting his testimony.

-CM