Interrogations-and-Confessions-Handbook

340 A Psychology of Interrogations and Confessions
The two ‘leading question’ tests had rather low loadings on this factor and correlated
poorly with the secondary suggestibility tests described above. Stukat
thought that the contradictory and co-judge tests were most clearly characterized
by personal influence and pressure from one individual upon another, so
that the individual’s need for conformity was the most significant functional determinant
in the secondary suggestibility process. Results from group comparisons
supported Stukat’s theory. That is, groups thought to have the strongest
need for conformity (e.g. young children, anxious people) were found to be most
suggestible. The findings were interpreted as showing that ‘functional determinants’,
such as needs, attitudes, values and differential reinforcement, influence
perception, memory and judgement, particularly in an unstructured
situation.
It is evident from the above discussion that there are several different types of
suggestibility. According to Gheorghiu (1989a), suggestion procedures have traditionally
been used to influence three unrelated processes—motor processes,
sensory processes and memory processes. We have seen that motor processes
are commonly associated with primary suggestibility, which in turn is related
to hypnotizability. Secondary suggestibility is found to cover a range of different
test phenomena, which are mostly but not exclusively associated with
sensory processes and perceptual judgements. Unfortunately, the tests that
seem to make up the secondary suggestibility factor are not always closely interrelated.
A broad definition of secondary suggestibility seems to have some
theoretical implications for interrogative suggestibility, but it is the influence
upon memory processes which is clearly most relevant.
After reviewing the literature on suggestibility I concluded that there were
good theoretical and empirical reasons for construing interrogative suggestibility
as a distinct type of suggestibility (Gudjonsson, 1987c). This view has been
reinforced by Gheorghiu (1989b) in his critical review of the development of
research on suggestibility. Indeed, interrogative suggestibility bears little resemblance
to traditional definitions of suggestibility, whether classified into
‘primary’ and ‘secondary’ phenomena as Eysenck proposes (Eysenck, 1943;
Eysenck & Furneaux, 1945) or ‘primary’, ‘challenge’ and ‘imagery’ suggestibility,
as argued by Evans (1967). In particular, on conceptual grounds no relationship
would be expected between interrogative suggestibility and primary
suggestibility.
THEORIES OF SUGGESTIBILITY
A number of theories have been put forward in order to explain primary and secondary
suggestibility. These have been extensively reviewed by Stukat (1958).
Primary suggestibility is most commonly explained in terms of an ideo-motor
response, which is fundamentally related to theories of conditioning. These
seem of no relevance to interrogative suggestibility and will not be discussed
in detail.
Various theories have been proposed to explain phenomena relevant to the
elusive entity of secondary suggestibility. For example, Binet’s (1900) tests of