Interrogations-and-Confessions-Handbook

Suggestibility: Historical and Theoretical Aspects 345
upon memory recall and testimony, was subsequently used by other workers,
such as Stern. The classical experimental work of Stern (1910, 1938, 1939)
demonstrated that leading questions can produce distorted responses because
they are phrased in such a way as to suggest the wanted response whether
correct or incorrect. Several subsequent studies have employed a similar or
modified procedure to that of Stern in order to elicit this type of suggestibility
(e.g. Burtt, 1948; Cohen & Harnick, 1980; Powers, Andriks & Loftus, 1979;
Trankell, 1958).
Davies, Flin and Baxter (1986) make the interesting observation that both
Binet and Stern used static pictures rather than simulated incidents as stimulus
material, although Stern (1910) did call for ‘event tests’ (i.e. studies of
incidents). Davies et al. argue that static pictures may limit the forensic relevance
of the material. This problem was overcome by the early innovative
British study of Pear and Wyatt (1914), who used a realistic simulated incident
as stimulus material.
Not all authors agree on a definition of interrogative suggestibility. Powers,
Andriks and Loftus (1979) define it as
. . . the extent to which they (people) come to accept a piece of post-event information
and incorporate it into their recollection (p. 339).
This definition highlights the importance of memory processing as an integral
part of interrogative suggestibility and it was for this reason that the fundamental
processes of perception and memory were discussed in detail in my
earlier book on interrogations and confessions (Gudjonsson, 1992a).
There are two main problems with the above definition of interrogative suggestibility.
First, it has not been proven that people necessarily incorporate the
suggested information into their recollection, although the information may be
accepted by the individual (i.e. they may believe it and accept it, but not incorporate
the information into memory—this will become an important issue
in some of the cases discussed in later chapters). Secondly, the definition is too
vague to provide the researcher with operationally testable hypotheses.
A more focused definition is provided by Gudjonsson and Clark (1986), who
define interrogative suggestibility as
The extent to which, within a closed social interaction, people come to accept messages
communicated during formal questioning, as the result of which their subsequent
behavioural response is affected (p. 84).
This definition comprises five interrelated components which form an integral
part of the interrogative process:
1. a social interaction;
2. a questioning procedure;
3. a suggestive stimulus;
4. acceptance of the stimulus; and
5. a behavioural response.