Mayo: comment on the repressed memory research

Here are some reflections on the repressed memory articles from Richard Gill’s post, focusing on Geraerts, et.al.,(2008).

1. Richard Gill reported that “Everyone does it this way, in fact, if you don’t, you’d never get anything published: …People are not deliberately cheating: they honestly believe in their theories and believe the data is supporting them and are just doing their best to make this as clear as possible to everyone.”

This remark is very telling. I recommend we just regard those cases as illustrating a theory one believes, rather than providing evidence for that theory. If we could mark them as such, we can stop blaming significance tests for playing a role in what are actually only illustrative attempts, or to strengthen someone’s beliefs about a theory.

2. I was surprised the examples had to do with recovered memories. Wasn’t that entire area dubbed a pseudoscience way back (at least 15-25 years ago?) when “therapy induced” memories of childhood sexual abuse (CSA) were discovered to be just that—therapy induced and manufactured? After the witch hunts that ensued (the very accusation sufficing for evidence), I thought the field of “research” had been put out of its and our misery. So, aside from having used the example in a course on critical thinking, I’m not up on this current work at all. But, as these are just blog comments, let me venture some off-the-cuff skeptical thoughts. They will have almost nothing to do with the statistical data analysis, by the way…

3. Geraerts, et.al., (2008, 22) admit at the start of the article that therapy-recovered CSA memories are unreliable, and the idea of automatically repressing a traumatic event like CSA implausible. Then mightn’t it seem the entire research program should be dropped? Not to its adherents! As with all theories that enjoy the capacity of being sufficiently flexible to survive anomaly (Popper’s pseudosciences), there’s some life left here too. Maybe , its adherents reason, it’s not necessary for those who report “spontaneously recovered” CSA memories to be repressors, instead they merely be “suppressors” who are good at blocking out negative events. If so, they didn’t automatically repress but rather deliberately suppressed: “Our findings may partly explain why people with spontaneous CSA memories have the subjective impression that they have ‘repressed’ their CSA memories for many years.” (ibid., 22).

4. Shouldn’t we stop there? I would. We have a research program growing out of an exemplar of pseudoscience being kept alive by ever-new “monster-barring” strategies (as Lakatos called them). (I realize they’re not planning to go out to the McMartin school, but still…) If a theory T is flexible enough so that any observations can be interpreted through it, and thereby regarded as confirming T, then it is no surprise that this is still true when the instances are dressed up with statistics. It isn’t that theories of repressed memories are implausible or improbable (in whatever sense one takes those terms). It is the ever-flexibility of these theories that renders the research program pseudoscience (along with, in this case, a history of self-sealing data interpretations).

5. Let’s give the researchers a bit more leeway. Let’s consider how they propose to “test” their hypothesized explanation. We still won’t need to look at the data for this…In Geraerts own research (as reported ‘in press’) “we found that the memories of CSA emerging during recovered memory therapy could not be corroborated, whereas those emerging outside therapy were corroborated just as often as memories of CSA that had never been forgotten.” (ibid., 23).

First of all, they could never have literally “found” that information, but let us grant for the sake of argument that they found the memories recovered in psychotherapy so unreliable that those spontaneously discovered/remembered are quite reliable in comparison. (They did not, by the way, check on the reliability of the CSA memories of their research subjects, so far as I can tell.) Doesn’t this admission show that recovered memory therapy was/is a highly unreliable practice?  If repressed memory therapists managed to“uncover” CSA “memories” by essentially manufacturing them, then isn’t there a danger that they are capable of implanting yet more false impressions in their subjects? I just wonder about the self-criticism here…

6. The gist of what they claim to show is that participants “recruited through ads in papers”, (ibid., 24) who reported spontaneously recovered CSA are actually just very good at deliberately forgetting unpleasant things (as compared to a control group who report no abuse). Two other groups are recruited: one with therapy-discovered CSA, and a second with people who never forgot CSA. So 4 groups in all.

In the main part of the experiment, all the participants write down positive and negative (anxious) events from the past few years, then are asked to suppress thinking about them during a 2 minute “suppression period.” The negative events are not the long ago CSA events, by the way. If one of the “target thoughts” pop into their minds in the suppression period, they are to trigger a joystick. (Various stages of imagining, expressing and suppressing thoughts ensue. They take home a 7-day diary to keep up the reports.)

I take it the researchers didn’t register in advance what would count as a failed result. I mean, let’s say the therapy-discovered CSA group reported statistically significantly fewer occurrences of the negative target during those two minutes (instead of the sponaneous group). That might be interpreted as indicating they tend to obey therapists’ wishes (they suppress when they’re told to suppress). That too could have been a publishable result, helping to explain the rampant false memories in this general group.

What they claim they hoped to show is that those who report spontaneously recovered memories are not repressors even though they think they are. That is, they hope to show the spontaneous recoverers do not “automatically” blank out negative events. Instead they are “suppressors” (those who deliberately don’t think about negative events). Let’s grant that was the pre-data goal. But is there really a difference here? Those who report spontaneously recovered memories claim they really never thought about the CSA until the day it was spontaneously brought to mind, but Geraerts claims they actually had remembered it but they forgot they remembered it. So, we know in advance that self-described repressors are easily redescribed by the researchers as suppressors.

All of these points, and many more besides, would arise in a critique before even looking at any results. It is based on logic and some information of the flaws of this and related research programs.We do not say the theories are implausible, only that the onus is on the researchers to show how they will conduct a stringent test of their theories, but we do not see that.

Note that the above criticisms are quite separate from the statistical questions Professor Gill was called in to consider. We don’t need shrewd statistics to criticize this research–although maybe we do for fraud. Yet as fraud buster-buster* Gill seems to be saying, there is a fine line between fraud and bad practices.

7. So what about the statistical analysis? “LSD tests indicated that people with spontaneous recovered memories reported significantly fewer occurrences of the anxious target thought than did the other groups.” (25) This is by means of Post-hoc Least-Significant-Difference (LSD) tests. Putting the best spin on the statistics, what is the upshot?

People reporting recovered memories are not repressors, but rather suppressors, as evidenced by the fact that they successfully block out negative events (when told not to think about them in an experiment), at least statistically significantly more often than do the other groups.

But notice that these people answered the ad, so they haven’t suppressed the memory of the CSA event. To Geraerts, further evidence that they are suppressors is the fact that they don’t think too much about the negative (target) event in the week after the experiment. But this seems irrelevant, since we know they remembered the CSA event.

But others are apparently giving the research greater mileage than I would. As Gill observes, “they honestly believe in their theories and believe the data is [are] supporting them”. I am prepared to be corrected by suppressors…

*This term seems more apt, now that I better understand Gill’s work in this arena.

REFERENCES:

Geraerts, E., McNally, R. J., Jelicic, M., Merckelbach, H., & Raymaekers, L. (2008). Linking thought suppression and recovered memories of childhood sexual abuse. Memory, 16, 22-28.

Gill, R. (2013). http://errorstatistics.com/2013/06/08/richard-gill-integrity-or-fraud-or-just-quesionable-research-practices/