The recent editors of Myers on Evidence of Interpersonal Violence (Myers 2016) notes that the most well-known of psychological instruments to assess suggestibility is the Gudjohnson Suggestibility Scales (GSS). The GSS is utilized by psychologists to evaluate whether defendant's confessions were voluntary. The author notes that it is doubtful that these instruments are sufficiently reliable for use in legal proceedings. It is noted that in Shanklin, 379 111 Dec 211 the trial judge did not err in subjecting the GSS to a Frye Henry.
The science in this area, as well as this author's forensic experience in this area, does not support this conclusion. The GCS scales were reviewed by Johnson and Franklin (1997). The GCS can assess the psychological vulnerability of a defendant or witness to leading questions and to shifting from one response, right or wrong, to a different response, under pressure. This test can provide valuable data to the court regarding an individual's susceptibility to providing false information during police questioning. This becomes a highly relevant matter when the Trier of Fact is assessing the validity of a confession or witness statements. The measure is also useful when the court is determining the voluntariness of a confession or Miranda Waiver.
Johnson and Franklin (1997) note that the correlations for suggestibility with the GSS were highly significant. Significant Temporal Consistency Scales have been obtained, comparing the GSS-1 and GSS-2 for a variety of populations over different time frames.
Grisso (1986), a noted forensic author and researcher reviewed the early validation studies in the GSS1 and concluded "construct validation research with the GSS has placed the forensic examiner in a good position to use the GSS scores when considering questions of an examinee's decreased resistance to subtle and overt pressure in interrogations by law enforcement officials (p147). Since the initial review, additional research has been done. Suggestibility has been found to correlate with a number of cognitive variables. Gudjohnson (2003, p 360-412) surveyed the relevant research. Suggestibility has a negative relationship to intelligence and recovery. Poor assertiveness, evaluative anxiety, state anxiety and avoidance coping strategies correlated with suggestibility. It has also been shown that although adolescents do not "yield" to leading questions more so than adults, they are more likely to have higher shift scores on the GSS (i.e. change an answer when provided with pressure or negative feedback). Sleep deprivation is also correlated with suggestibility. Research has shown that false confessions have higher GSS scores than forensic patients and those who asserted their innocence. Johnson and Franklin (1997) note that the GSS was developed using normative data from Great Britain and Iceland. Yet, they state that the test is appropriative for use with the US population. They note that London is a multi-cultural city. Moreover, there were few differences in performances between the scores of populations in Iceland and Great Britain.
The GSS provides excellent behavioral data relating to how an individual responds when given leading questions and presented with negative feedback. The GSS measures behavioral responses to leading questions and negative feedback- a similar process to interrogations. The GSS is particularly resistant to exaggeration or feigning of interrogative suggestibility. The GSS provides a "real time" protocol for assessing the effects of leading questions and interrogative pressure to change answers.
The Gudjonnson Compliance Scale (GCS) measures acquiescence to authority. This effect is quite robust. This examiner has observed defendants becoming anxious as soon as the examiner introduces himself. Highly compliant and acquiescent individuals are particularly vulnerable to coercive police questioning.
Personality Testing is useful in assessing dependency and passivity. Individuals who score high on traits such as dependency, anxiety, and passivity are particularly prone to producing false confessions.
Past life events should be considered in analysis of confessions. Individuals with a history of abandonment may become highly anxious when threatened with loss of one's children and going to jail. The threat of jail serves as a "cue" that triggers prior anxiety.
The GSS and GCS are valuable objective tests; with standardized protocols manuals. The measure can be of great utility to psychologists in analysis of confessions.