Interrogations-and-Confessions-Handbook

364 A Psychology of Interrogations and Confessions
did before (Gudjonsson, 1984a; Register & Kihlstrom, 1988). Typically Yield
2 is about one or two points higher than Yield 1; a score of 13 or above falls
outside the normal range.
Yield 2 has been used in some of the more recent research with the GSS 1
and GSS 2. It provides additional information in that it tells the examiner
precisely how interrogative pressure, which is administered in the form
of negative feedback, affects the subsequent susceptibility of the subject
to suggestive questions. Yield 2 is more highly correlated with Shift than
Yield 1 among normal subjects, forensic cases and children (Gudjonsson,
1984a), which means that it gives a better indication than Yield 1 of the
subjects’ vulnerability to yielding to leading questions when placed under
interrogative pressure.
6. Total Suggestibility. This is the sum of Yield 1 and Shift. This gives an
indication of the subject’s overall level of suggestibility. The mean Total
Suggestibility score for normal subjects is 7.5 on the GSS 1, with a standard
deviation of 4.6. This means that a score of 16 or above falls outside
the normal range (i.e. 95th percentile rank). The mean score for forensic patients,
which includes court referrals, is about 10 with a standard deviation
of 6.
7. Confabulation. Confabulation is the most recently developed measure of
the GSS. It refers to problems in memory processing where people replace
gaps in their memory with imaginary experiences that they believe to be
true. Confabulation can be measured on the memory part of the GSS 1
and GSS 2 stories. This includes major distortions in the story’s content or
that pieces of information have been added to the story. Clare, Gudjonsson,
Rutter and Cross (1994) classified confabulations on the GSS 2 into two
distinct groups:
� distortions, which represent a major change in the details of an existing
‘idea’ (e.g. house mentioned instead of a bungalow, one boy instead of two
boys) and
� fabrications, where a new or novel element is added to the narrative
(e.g. introducing a name of a person or place not mentioned in the story).
Distortions and fabrications are typically added to make up the total number
of confabulations. For details about the scoring readers should read the GSS
Manual (Gudjonsson, 1997a).
Reliability
The internal consistency of the 15 Yield 1 and 15 Shift items on the GSS 1
was measured by Cronbach’s alpha for 195 subjects (Gudjonsson, 1984a). The
coefficients were 0.77 and 0.67 for Yield 1 and Shift, respectively. Singh and
Gudjonsson (1987) recommended some modifications in the scoring of Shift,
which increased the internal reliability of the measure to 0.71. This consisted
of slight modification in the scoring of Shift and increased the number of items
from 15 to 20. This means that a distinct change in the answers given after
‘negative feedback’ applies to all the 20 items on the GSS 1, and not just to the
15 ‘leading’ items, as had been used in the original work.