Cultic Studies Journal, Vol. 14, No. 2, 1997, page 4
Hypnosis and the Iatrogenic Creation of Memory:
On the Need for a Per Se Exclusion of Testimony Based on
Hypnotically Influenced Recall
Robert A. Karlin, Ph.D.
Rutgers University
Martin T. Orne, M.D., Ph. D.
University of Pennsylvania
Abstract
An overview of Karlin and Orne (1996) and related research shows why
hypnotically influenced testimony is more unreliable and misleading than
testimony based on ordinary recall. McConkey and Sheehan‟s (1995) report
on a recent series of forensic hypnosis cases is then used to illustrate the
need for a per se exclusion. Next, several points raised by Scheflin (1996) are
discussed. First, as in Amytal interviews --whose per se exclusion most
scholars accept --testimony influenced by hypnosis tends to be believable,
vivid, and misleading. Second, Scheflin‟s (1994, 1996) challenge to per se
exclusion based on the case of an abused child is answered. Third, the time
course of Ms. Borawick‟s hypnotically influenced retrieval of putative abuse
memories is examined. Fourth, consideration is given to the inherent
incredibility of Ms. Borawick‟s claims and the costs of debating the
admissibility of such testimony on a case-by-case basis. Combining clinical
hypnosis and psychotherapy will not result in objectively reliable memories,
since each procedure encourages recall that may be subjectively important,
but is often historically inaccurate. In the therapeutic context a lack of
understanding of iatrogenic effects is hazardous, and hypnotically influenced
testimony, with rare and easily specifiable exceptions, should be
automatically excluded at trial.
In this paper, we will first review some of the points we made in our original paper (Karlin &
Orne, 1996). Then, we will comment directly on points Scheflin (1996) made and answer
the challenge he laid down in that paper. We will pay special attention to the notion that
safeguards for forensic hypnosis will protect the fact-finding process from the distortions
inherent in admitting hypnotically influenced testimony.1 Finally, we will briefly review the
evidence for the contention that memories emerging from hypnotic procedures during
psychotherapy are somehow more likely to be historically factual than hypnotically based
memories recovered in other contexts.
An Overview of Our Original Paper
Hypnotic procedures produce testimony that, for a number of reasons, is less reliable than
ordinary recall (cf. Dinges et al., 1992 Orne, Soskis, Dinges, &Carota Orne, 1984). First, a
standard hypnotic induction asks people to relax, close their eyes, and experience, for
example, a motor movement that “happens by itself.” Response to such suggestions
requires one to lower critical judgment temporarily (e.g., ignore the absurdity of the idea
that one‟s hands can move by themselves) and blur the boundary between fantasy and
reality. Second, when hypnosis is used to “refresh recollection” the participation of
authorities (from the police to an expert hypnotist) and expenditure of time and effort
suggest strongly that memory change through hypnosis is possible and expected. Any
subsequent change is also legitimized by hypnosis.

Cultic Studies Journal, Vol. 14, No. 2, 1997, page 5
Further, given the demand characteristics inherent in hypnosis (cf. Orne, 1959, 1970), it is
unsurprising that hypnotic suggestions for increased memory result in heightened
production of information. However, it is also unsurprising that much of the new material
gained in hypnosis is incorrect (cf. Carota Orne, Whitehouse, Dinges, &Orne, 1996
Whitehouse, Dinges, Carota Orne, &Orne, 1988). Hypnosis also often produces an overall
increase in confidence about both correct and incorrect memories this increased confidence
weakens the usual correlation between certainty and accuracy, and “confident errors” result
(cf. Sheehan, 1988). Consequently, a jury may be presented with a factually incorrect
witness who provides vivid detail with more confidence than is warranted. And juries are
swayed by witness confidence and detail, both of which hypnosis promotes. Finally, subjects
are generally unable to discriminate accurately what they remembered of the original
events before hypnosis, what material they learned subsequently from other sources, and
what additional material they remembered during hypnosis (Whitehouse, Carota Orne,
Orne, &Dinges, 1991).
When we take together the decreased critical judgment, the blurring of the boundary
between fantasy and memory, the increase in certainty unrelated to accuracy, the
misattribution of whether information was learned during hypnosis or before it, and the fact
that hypnosis makes a major change in memory credible, we find a formidable basis for
automatically keeping hypnotically influenced testimony out of court.2
It is noteworthy that all the effects just indicated are part of the social psychology of the
hypnotic context they are not dependent on the hypnotizability of the specific subject. For
example, research in the second author‟s laboratory has shown a greater increase in
memory errors among low hypnotizable subjects in a hypnotic condition than in a
nonhypnotic condition during repeated recall trials. Further, lows who underwent waking
and hypnotic recall trials displayed more source misattribution than their counterparts
whose recall trials were both nonhypnotic. Moreover, all groups of subjects tended to
misattribute their memories to nonhypnotic rather than hypnotic recall trials (Carota Orne et
al., 1996 see also Dinges et al., 1992 Whitehouse et al., 1991). Thus, contrary to
Scheflin‟s (1996) assertions, these and other recent findings have supported the early
1980s appellate court decisions that automatically excluded hypnotically influenced
testimony (e.g., People v. Shirley, 1982) and the American Medical Association‟s (1985,
1994) repeated calls for such restrictions. Further, contrary to Scheflin‟s (1996) views,
these studies clearly distinguish hypnotizability as a stable individual difference dimension,
measured by overt response to standardized hypnotic suggestions, from the effects of
hypnosis as a social psychological context and an invitation to a particular cognitive style.3
Additionally, if a subject is relatively highly hypnotizable, the suggestions to relive events
that routinely follow hypnotic induction in the forensic context may have additional effects.
First, the frequent inclusion of confabulated, vivid detail in the new material makes
hypnotically influenced memories more credible (Dywan, 1995). Also, fantasies entirely
unrelated to what actually occurred may also be suggested during hypnosis and
remembered as veridical (Laurence, Nadon, Nogrady, &Perry, 1986 Laurence &Perry,
1983). This is especially the case when there are no clear original memories to overlay (cf.
Orne, 1979 see also Karlin, 1983) or when, as in civil cases, the hypnotized party has a
strong interest in “remembering” one version of events (cf. Karlin, 1997 State v. Hurd,
1981). Finally, more highly hypnotizable subjects may subjectively relive events and vividly
experience a version of the past. Unfortunately, vividness has no relation to historical
accuracy, but again increases confidence inappropriately (cf. Frankel, 1994).
The use of hypnosis to increase memory is often justified by the notion that it allows people
to overcome the effects of traumatically induced psychogenic amnesia (cf. Kanovitz, 1992).
In our original paper, we noted that psychogenic amnesia (as distinguished, for example,
from unwillingness to remember, ordinary forgetting, and failure to originally encode