Interrogations-and-Confessions-Handbook

Suggestibility: Empirical Findings 361
results parallel those of the use of the GSS with adults in terms of Yield and
Shift items loading on different factors.
Endres (1997) had developed the Bonn Test of Statement Suggestibility
(BTSS) to measure individual differences in interrogative suggestibility in children
aged 4–10 years. The test is partly based on the format of the GSS.
The German version of the test has been translated into Dutch and validated
(Candel, Merckelbach & Muris, 2000).
Can interrogative suggestibility be reliably measured? Is there empirical
evidence that interrogative suggestibility differs from suggestibility described
in a hypnotic context? How does suggestibility relate to the constructs of
‘compliance’ and ‘acquiescence’? These are basic types of question that are addressed
in this chapter before the more empirical findings are discussed in relation
to the Gudjonsson–Clark model. Many of the theoretical questions raised
in Chapter 13 are dealt with experimentally in this chapter.
The best way of testing the merit of a particular theory is on the basis of
how well the various hypotheses derived from the theory can be supported by
empirical findings. A number of hypotheses derived from the Gudjonsson–Clark
model were listed in Chapter 13 and I now examine how well the theory has
stood up to empirical investigations.
THE GUDJONSSON SUGGESTIBILITY SCALES
After laying the foundations for the theoretical work on interrogative suggestibility,
which was discussed in detail in Chapter 13, the construction and
early validation of a suggestibility scale were used to assess the individual’s
responses to ‘leading questions’ and ‘negative feedback’ instructions when being
asked to report a factual event from recall. The scale, referred to as the
Gudjonsson Suggestibility Scale (GSS 1), is particularly applicable to legal issues,
such as police officers’ questioning of witnesses to crime and interrogation
of criminal suspects. It employs a narrative paragraph describing a fictitious
robbery, which is read out to the subject. He or she is then asked to report all that
can be recalled about the story. After the person has given free immediate and
delayed recall to the story (the delay is generally about 50 minutes), he or she is
asked 20 specific questions, 15 of which are subtly misleading. After answering
the 20 questions the person is told that he or she has made a number of errors
(even if no errors have been made), and it is therefore necessary to ask all the
questions once more. The person is asked to be more accurate than before. Any
change in the person’s answers from the previous trial is noted as Shift. The
extent to which people give in to the misleading questions is scored as Yield 1.
Yield 1 and Shift are typically added together to make up Total Suggestibility.
Grisso (1986) reviewed the early validation studies on the GSS 1 and
concluded:
Construct validation research with the GSS has placed the forensic examiner in
a good position to use GSS scores when considering questions of an examinee’s
decreased resistance to suggestion or subtle pressure in interrogations by law
enforcement officers (p. 147).