Journal of Applied Research in Intellectual Disabilities 2002, 15, 8–17
Interrogative Suggestibility among Witnesses with Mild Intellectual Disabilities: the Use of an Adaptation of the GSS Rebecca Milne Institute of Criminal Justice Studies, University of Portsmouth, Portsmouth, Hampshire, UK
Isabel C. H. Clare Department of Psychiatry, Section of Developmental Psychiatry, University of Cambridge
Ray Bull Department of Psychology, University of Portsmouth, Portsmouth, Hampshire, UK Paper accepted November 2001 Background As part of the assessment of witnesses’ ability to provide an account to the police and the courts, information is sometimes sought concerning their level of interrogative suggestibility. The most widely used measure for this is the Gudjonsson Suggestibility Scale (GSS, Gudjonsson 1997), which has two parallel forms (GSS 1 and GSS 2). However, the GSS relates to a verbally presented narrative, not to a visual event, as is more common to witness situations. Methods The present study adapted the scale’s format so that the questions referred to a videotaped incident that had been viewed 24 h earlier by men and women with mild intellectual disabilities (n ¼ 47) and their ‘general population’ counterparts (n ¼ 38). Results The pattern of results was identical to that typically obtained using the GSS in that: (1) compared with their general population counterparts, the participants with intellectual disabilities were more suggestible because of their vulnerability to the ‘misleading questions’; (2) suggestibility scores correlated with the participants’ verbal recall of the incident, and (3) both participants with intellectual disabilities and their general population counterparts who were misled by questions in the form of two false alternatives were more likely to select the latter option. Conclusions The implications of these findings for psychological assessments of potential witnesses are discussed.
Introduction There is now, at last, in England and Wales, official acknowledgement that the witness evidence of people with intellectual disabilities may be crucial for police investigations and the prosecution of offenders (Sanders et al. 1997; Bull 1999; Kebbell & Hatton 1999; Gudjonsson et al. 2000; Milne & Bull 2002). Increasingly, therefore, criminal justice system personnel are seeking advice from health and social care practitioners, and particularly psychologists, to help these witnesses in providing information to the police that can, in turn, be used in court. This is especially so since the implementation of the
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Youth Justice & Criminal Evidence Act 1999, which provides, for the first time, for the use of ‘special measures’ to assist ‘vulnerable’ witnesses or victims, such as men and women with intellectual disabilities, to give evidence at interview and in the courtroom. It has been argued (e.g. Kebbell & Wagstaff 1999) that to be credible, a witness must be both willing and able to provide information that is accurate, reliable, and complete. Willingness refers to the witness’s motivation to report the truth, whilst ability, which is the focus of interest here, refers to the capacity to recall and recount accurately the event in question. In this context, capacity is likely to reflect the interaction of a number of factors. These include the details of the alleged offence (Kebbell & Wagstaff 1999), personal characteristics relating to the witness (such as his or her cognitive functioning, personality, and mental state; see reviews by Gudjonsson 1992, 1993), and the strategies used by the police and other criminal justice personnel to elicit information (Milne & Bull 1999). Among the personal characteristics that have been identified as being of potential relevance to a witness’s capacity to provide accurate, reliable, and complete information, the concept of ‘interrogative suggestibility’ has been of particular theoretical and practical importance (see reviews by Gudjonsson 1992, 1997; Clare & Gudjonsson 1995). Interrogative suggestibility has been defined (Gudjonsson & Clark 1986) as ‘the extent to which, within a closed social interaction, people come to accept messages communicated during formal questioning, as a result of which their subsequent behavioural response is affected’ (p. 84). It has been conceptualized as comprising two distinct vulnerabilities; (i) to ‘Yield’ to questions that are leading because they indicate the answer that is required; and (ii) to ‘Shift’ initial answers in response to ‘negative feedback’ from the interviewer. These vulnerabilities can be measured using either of the parallel versions of the Gudjonsson Suggestibility Scale (GSS 1 and GSS 2, Gudjonsson 1984, 1987, 1997), a behavioural test constructed particularly for the assessment of suggestibility that has been validated extensively (see Gudjonsson 1997). Both scales comprise a narrative passage, which is read to the participant to obtain measures of free recall. Subsequently, 20 questions, 15 of which are misleading (i.e. they infer the incorrect response, including five false alternative questions), are presented. The interviewee’s ‘Yield’ score (i.e. the number of questions to which he or she gives an incorrect response by ‘going along’ with the premise of the question) is determined. These items are interspersed with five nonleading (true) questions. Regardless of the accuracy of the responses given by the interviewee, the interviewer then provides ‘negative feedback’ (i.e. the interviewer informs the interviewee that they have provided a number of incorrect responses and that they must be more accurate in answering the questions when repeated) and insists that it is necessary to present the questions a second time. The extent to which the interviewee subsequently changes their initial answers to these 20 questions in response to this ‘negative feedback’ from the interviewer results in their ‘Shift’ score. ‘Total suggestibility’ comprises the sum of the ‘Yield’ and ‘Shift’ scores. A number of studies have found that, compared with their counterparts of average intellectual ability, people with intellectual disabilities have more limited memories and are more vulnerable to questions that are ‘misleading’ (Tully & Cahill 1984; Clare & Gudjonsson 1993; Gudjonsson & Clare 1995; Cardone & Dent 1996; Gudjonsson 1997; Everington & Fulero 1999). Consistent with their vulnerability to acquiescence (answering ‘yes’ to closed ‘yes’/‘no’ questions, Clare & Gudjonsson 1993; Heal & Sigelman 1995), to which the misleading questions are conceptually related (Gudjonsson 1997), people # 2002 BILD Publications, Journal of Applied Research in Intellectual Disabilities, 15, 8–17
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with mild intellectual disabilities are more likely to ‘Yield’ than their general population counterparts (Clare & Gudjonsson 1993; Cardone & Dent 1996). However, there is no significant difference between the two groups in their response to ‘negative feedback’ (Clare & Gudjonsson 1993; Cardone & Dent 1996; Gudjonsson et al. 2000). Whilst, in part, this probably reflects a ‘ceiling’ effect resulting from the very high initial ‘Yield’ (Gudjonsson 1990), from clinical experience, it sometimes appears that, having been misled initially, people with intellectual disabilities try to cope with the feedback by simply repeating the response they gave initially. Using the GSS (Form 1), Tully & Cahill (1984) found that suggestibility scores predicted the accuracy of the accounts of witnesses with intellectual disabilities during police interviewing. Though they only examined ‘Total suggestibility’, rather than ‘Yield’ and ‘Shift’ separately, ‘Total suggestibility’ scores (i.e. ‘Yield’ plus ‘Shift’ scores) obtained before a staged incident correlated negatively with the number of items of correct information provided by the participants and positively with the amount of erroneous information. This implies that suggestibility is, at least in part, a cognitive phenomenon. The GSS has been criticised (Baxter 1990; Cardone & Dent 1996), because it is based on a verbally presented story that is quite unlike most real criminal incidents, perhaps limiting its validity. In addition, it has been suggested (Cardone & Dent 1996) that the use of the GSS may overestimate the suggestibility of men and women with intellectual disabilities because multimodal input (e.g. visual and auditory such as in a real life event) as opposed to unimodal input (used in the GSS) may aid the encoding and recall of memory traces (Kosslyn & Koenig 1992), leading to more complete and accurate recall. Since vulnerability to misleading questions is normally (negatively) related to recall (e.g. Tully & Cahill 1984), it would be expected that material presented in more than one modality would increase participants’ resistance to misleading questions (i.e. lead to lower ‘Yield’ scores). In contrast, ‘Shift’, which is thought to be more closely related to anxiety and coping mechanisms (Sharrock & Gudjonsson 1993), is less likely to be affected by presentation in more than one modality. In support of this suggestion, Cardone & Dent (1996) found that presenting the GSS visually as well as verbally improved the completeness and accuracy of recall and reduced ‘Yield’ among people with mild intellectual disabilities, but it had no effect on ‘Shift’ scores. However, the visual presentation in this study merely comprised 17 slides highlighting key points in the verbal story; therefore, it has limited ecological validity. The aim of the present study was to examine the impact on suggestibility among adults with mild intellectual disabilities and their counterparts in the general population of a multimodal (visual and verbal) presentation with improved ecological validity. It was expected that, notwithstanding the change in format, the intellectually disadvantaged participants would be more suggestible than their peers and that there would be a negative relationship between recall and susceptibility to misleading questions.
Method Participants There were two groups of participants, one of which comprised an administrative sample of 34 men and 13 women (mean age: 35 years; range: 19–59 years) attending six designated day-services for people with mild intellectual disabilities. Whilst it was not # 2002 BILD Publications, Journal of Applied Research in Intellectual Disabilities, 15, 8–17
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possible to assess the intellectual functioning of the participants, all of them were able to express themselves verbally, using sentences. As far as was known, none of them lived entirely independently. Since administrative samples may differ according to local criteria for service eligibility, the centres from which the participants were recruited were based in two distant geographical locations (Portsmouth and London). The other group comprised 13 men and 25 women (mean age: 39 years; range: 19– 62 years) from Cambridge, recruited from a local job centre and through a newspaper advertisement. Many of the participants were employed and the majority had academic qualifications. In both groups, most participants were of white, British ethnic origin. Event A 3 min video recording, edited from an educational film about road safety, was used. The recording showed a boy, Jamie, knocked down whilst crossing a road on his way to school by a man driving a yellow car. The event was chosen because it was dramatic, realistic without being upsetting, and suitable for viewers from the two groups. It contained visual and auditory information. Adaptation of the GSS (see Appendix 1) A suggestibility measure, based on the Gudjonsson Suggestibility Scale, was devised. The adapted scale contained 12 questions about the video-recording. Four of these were misleading, in that they created an expectation of an affirmative answer that would be an incorrect response (e.g. ‘Was the man in the yellow car driving faster than the speed limit?’ when the viewer had no information about either the driver’s speed or the speed limit for the road), another four were false alternatives (or forced-choice questions), where both the alternatives were wrong (for example, ‘Did the boy have a bandage on his head or his arm?’ when no bandage was shown). These questions were interspersed with four non-leading questions relating to information which was shown in the film (e.g. ‘Was the boy’s name Jamie?’). Procedure The video-taped event was shown on a television set to small groups of participants. The participants were asked to watch and listen carefully because they would be asked later about what they thought of the film. Approximately, 24 h later, each participant was interviewed individually as part of a larger study comparing the effect on the recall of witnesses of different types of questioning (see Milne et al. 1999). At the end of the interview phase of the study, the adaptation of the GSS scale was presented, following the instructions provided by Gudjonsson (1997, p. 11). Each question was read out clearly, in turn, and a response sought. At the end, regardless of the participant’s responses, he or she was given ‘negative feedback’ by being told firmly: ‘You have made a number of errors. It is therefore, necessary to go through the questions once more, and this time try to be more accurate.’ The questions were repeated. Each person was told that they had done well, and they were paid a standard fee for participating. The responses to the questions prior to, and following the negative feedback, were scored. # 2002 BILD Publications, Journal of Applied Research in Intellectual Disabilities, 15, 8–17
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Scoring Adaptation of the GSS The responses to this measure were scored in two ways. Firstly, the scoring criteria devised for the GSS (Forms 1 and 2, Gudjonsson 1997) were used to provide ‘Yields 1 and 2’, ‘Shift’, and ‘Total suggestibility’ scores, as follows: 1 ‘Yield 1’. Each of the eight misleading questions which was answered affirmatively, or for which a false alternative was chosen, prior to the negative feedback, was scored. Scores on ‘Yield 1’ could range from zero to eight. 2 ‘Yield 2’. This was similar to ‘Yield 1’, but it referred to the answers given after the negative feedback. It indicated the impact of the feedback on each participant’s vulnerability to misleading questions. Scores on ‘Yield 2’ could range from zero to eight. 3 ‘Shift’. A distinct change in response to any of the repeated 12 questions following the negative feedback was scored. The range of possible scores was, therefore, between zero and 12. 4 ‘Total suggestibility’. The range of possible scores for ‘Total suggestibility’ (i.e. the sum of ‘Yield 1’ and ‘Shift’) was between zero and 20. Secondly, each participant’s response to each misleading and false alternative question was scored as ‘misled’ (as an incorrect response, as for ‘Yield 1’; range: 0–8); as ‘resistant’ (a definite negative response, i.e. a correct response; range: 0–8), or as ‘don’t know’ (range: 0–8). It must be noted that for each participant raw scores are expressed as a percentage of the total possible score (see Tables 1 and 3). Interview data The reported information elicited during the interview phase of the study was coded as either ‘correct’, ‘incorrect’ or a ‘confabulation’. A piece of information was coded as incorrect (or ‘distortion’) if the ‘recalled’ detail was discrepant with the relevant detail in the film (e.g. red jumper instead of black jumper; an error concerning colour). If a detail was mentioned that was not present in the film, it was coded as a confabulation (or ‘fabrication’; for further details of the scoring see Milne et al. 1999).
Results Comparison of suggestibility between the two groups Table 1 shows the mean percentage scores for the two groups on all six suggestibility variables. The mean percentage scores were compared statistically using analysis of variance. As expected, compared with their ‘general population’ counterparts, the group of participants with mild intellectual disabilities were more suggestible. The difference in ‘Total suggestibility’ between the two groups arose from the greater susceptibility to ‘misleading questions’ of the ‘intellectual disabilities’ group. Initially, they were significantly less likely to provide ‘resistant’ or ‘don’t know’ responses to the misleading questions. However, there was no significant difference in their ‘Shift’ scores, indicating that they did not respond differently to ‘negative feedback’. # 2002 BILD Publications, Journal of Applied Research in Intellectual Disabilities, 15, 8–17
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Table 1 Mean percentage suggestibility scores for the two groups of participants Population type Suggestibility score
Intellectual disabilities
Yield 1 Yield 2 Shift Total suggestibility score Resistance Don’t know
General population
30 32 19 25 31 27
61 64 22 40 17 10
P < 0.0001.
The effect of recall on suggestibility Correlation analyses (Pearson’s Product Moment) were conducted to see if recall in the preceding interview was related to the responses to the suggestive questions. The analysis took the form of correlating each type of response to the suggestibility scale (i.e. Yield 1 and 2, etc.) with the interview recall scores for total correct, total incorrect and total confabulation (where mean correct recall for intellectual disabilities ¼ 87, and general population (GP) ¼ 181; where mean number of incorrect details for intellectual disabilities ¼ 14 and GP ¼ 17; and mean confabulations for intellectual disabilities ¼ 18, and GP ¼ 8; see Milne et al. 1999 for full interview data and analysis). Table 2 shows that whilst there was no significant relationship between the number of incorrect items recalled and any of the components of suggestibility, participants who recalled more correct information in the preceding interview were less susceptible to misleading questions both prior to, and following, negative feedback. They were also much more likely to give ‘don’t know’ responses. In addition, the number of confabulations during the preceding interview correlated with susceptibility to misleading questions both prior to, and following, feedback and difficulty in providing a ‘don’t know’ response. A further analysis was then carried out. Position bias in incorrect responses to the false alternatives Chi-squared analysis was conducted to examine which of the two options (i.e. first or last), were chosen by the participants who were misled (as opposed to resisting or giving
Table 2 Correlation between recall and responses to the suggestibility scale Recall Suggestibility
Correct
Incorrect
Confabulations
Yield 1 Yield 2 TSS Not misled Don’t know
0.417 0.444 0.323 0.353 0.291
ns ns ns ns ns
0.318 0.272 ns 0.236 0.246
TSS is the total suggestibility score; P < 0.05,
P < 0.01,
P < 0.001,
P < 0.0001.
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Table 3 Percentage forced-choice question responses for the two groups of participants Population group Response
Intellectual disabilities
General population
First Last Resistance Don’t know
57 96 29 22
19 54 42 45
a ‘don’t know’ response). Participants (both adults with intellectual disabilities and those from the general population) were significantly more likely to pick the last option (w2 ¼ 24, df ¼ 1, P < 0.001).
Discussion The main aim of the present study was to compare suggestibility among adults with mild intellectual disabilities and their counterparts in the general population, using an adaptation of an established measure (the GSS, Gudjonsson et al. 1997) with a visual and auditory event. In addition, it was expected that there would be a negative relationship between recall and susceptibility to misleading questions. As expected, adults with intellectual disabilities were more suggestible on all measures, and less resistant to misleading questions than their counterparts from the general population. This is similar to previous research which has found that, compared with their peers, men and women who are intellectually disadvantaged are more susceptible to misleading questions (e.g. Clare & Gudjonsson 1993; Gudjonsson & Clare 1995; Everington & Fulero 1999). However, consistent with previous findings (Clare & Gudjonsson 1993; Cardone & Dent 1996), there was no difference between the two groups in the extent to which they changed their responses following ‘negative feedback’ (‘Shift’). These findings can be explained within Gudjonsson & Clark’s (1986) theoretical model of interrogative suggestibility. This is based on a socio-cognitive perspective, where suggestibility is dependant upon the coping strategies that people use when faced with the ‘uncertainty’ and ‘expectations’ of the interrogative situation. In their dichotomous model, interrogative suggestibility comprises two distinct susceptibilities (i) to ‘Yield’ to leading questions, which relates to the reliability of testimony and closely reflects memory processes; and (ii) to ‘Shift’, the change from the initial answer in response to ‘negative feedback’, where ‘Shift’ is related to coping processes which are particularly affected by certain personality characteristics and experience (e.g. Gudjonsson 1992). As would be predicted from their model, in the present study ‘Yield 1’ and ‘Yield 2’ and the ‘Total suggestibility’ scores were negatively related to correct recall and positively related to confabulations reported in the preceding interview, and seemed to reflect cognitive factors. However, in contrast, ‘Shift’ scores were not, supporting the suggestion that ‘Shift’ primarily reflects personality characteristics and social experience. Interestingly, it was also found that when adults with intellectual disabilities responded to false alternatives (i.e. questions that do not contain the correct alternative) # 2002 BILD Publications, Journal of Applied Research in Intellectual Disabilities, 15, 8–17
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they chose the last option, i.e. have a last-option bias. This is to some extent consistent with Prosser & Bromley’s (1998) suggestion that this reflects the difficulties of adults with intellectual disabilities in remembering the reply choices. However, in the present study, the general population also showed this last-option bias. The implication is that questions of this type should be avoided when interviewing any interviewee, regardless of intellectual disability. It would have been useful to have included a greater number of different formats of the to-be-remembered material. At the same time, it would have been helpful to involve ‘general population’ participants who were more representative of this group. Despite recruiting primarily through a job centre, some of our participants had undergraduate and even postgraduate degrees. Nevertheless, the similarity between the pattern of our findings and those obtained by Gudjonsson (1984 et seq.; see Gudjonsson 1997 for review) indicates that, despite its apparent lack of ecological validity, the Gudjonsson Suggestibility Scale seems a useful measure of vulnerability to misleading questions and interrogative pressure. It should be maintained as part of the psychological assessment of potential witnesses with intellectual disabilities. Both sets of findings suggest that compared with their counterparts in the general population, adults with intellectual disabilities are much more susceptible than their peers to misleading questions about material that they do not recall. The findings indicate that interviewers need, firstly, to make great efforts to assist people with intellectual disabilities to recall freely and spontaneously as much correct information as possible about alleged offences (for example, using the cognitive interview, Milne et al. 1999) and, secondly, to try to avoid questions that imply the desired response. Psychological assessments of potential witnesses to criminal offences should stress that recent studies (Bull 1999; Milne 1999; Kebbell et al. 2002) suggest that, when interviewed appropriately, people with intellectual disabilities can provide accurate accounts of events. The onus must rest with the interviewer not to ask inappropriate questions. However, there may be a long way to go before such methods are routinely used by the police (Milne & Bull 1999) or the courts (Kebbell et al. 2002). Only rigorous training models that span an interviewer’s career and adequate supervision in the workplace will help the transference of appropriate questioning skills into the field (Clarke & Milne 2001).
Acknowledgments The present authors are grateful to all the participants for their help, to the staff at the centres, to our interviewers, and to Professor Gisli Gudjonsson for his support for this study. The study was carried out in part fulfilment of the first author’s PhD, which was funded by a bursary from the University of Portsmouth. Additional funding was provided by the Mental Health Foundation – the present authors are also grateful to them for their support. In addition, the present authors would like to thank two anonymous reviewers for their helpful comments on a prior draft of this paper.
Correspondence Any correspondence should be directed to Dr Rebecca Milne, Institute of Criminal Justice Studies, University of Portsmouth, Museum Road, Portsmouth, Hampshire PO1 2QQ, UK. E-mail:
[email protected]; Tel.: þ44 2392843927. # 2002 BILD Publications, Journal of Applied Research in Intellectual Disabilities, 15, 8–17
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References Baxter J. (1990) The suggestibility of child witnesses: a review. Applied Cognitive Psychology 4, 393–407. Bull R. (1999) Questioning approach. Solicitors’ Journal July, 706–707. Cardone D. & Dent H. (1996) Memory and interrogative suggestibility. The effects of modality of information presentation and retrieval conditions upon the suggestibility scores of people with learning disabilities. Legal and Criminological Psychology 1, 165–177. Clare I. C. H. & Gudjonsson G. (1993) Interrogative suggestibility, confabulations, and acquiescence in people with mild learning disabilities (mental handicap): implications for reliability during police interrogations. British Journal of Clinical Psychology 32, 295–301. Clare I. C. H. & Gudjonsson G. (1995) The vulnerability of suspects with intellectual disabilities during police interviews: a review and experimental study of decision-making. Mental Handicap Research 8, 110–128. Clarke C. & Milne R. (2001) National Evaluation of the PEACE Investigative Interviewing Course. Police Research Group report no. PRAS/149, London. Everington C. & Fulero S. (1999) Competence to confess: measuring understanding and suggestibility of defendants with mental retardation. Mental Retardation June, 212–220. Gudjonsson G. H. (1984) A new scale of interrogative suggestibility. Personality and Individual Differences 5, 303–314. Gudjonsson G. H. & Clark N. K. (1986) Suggestibility in police interrogation: a social psychological model. Social Behaviour 1, 83–104. Gudjonsson G. H. (1987) A parallel form of the Gudjonsson Suggestibility Scale. British Journal of Clinical Psychology 26, 215–221. Gudjonsson G. H. (1990) The relationship of intellectual skills to suggestibility, compliance and acquiescence. Personality and Individual Differences 11, 227–231. Gudjonsson G. H. (1992) The Psychology of Interrogations, Confessions and Testimony. Wiley, Chichester. Gudjonsson G. H. (1993) Confession evidence, psychological vulnerability and expert testimony. Journal of Community and Applied Social Psychology 3, 117–129. Gudjonsson G. H. (1997) The Gudjonsson Suggestibility Scales Manual. Psychology Press. Gudjonsson G. H. & Clare I. C. (1995) H. The relationship between confabulation and intellectual ability, memory, interrogative suggestibility and acquiescence. Personality and Individual Differences 19, 333–338. Gudjonsson G. H., Murphy G. H. & Clare I. C. H. (2000) Assessing the capacity of people with intellectual disabilities to be witnesses in court. Psychological Medicine 30, 307–314. Heal L. W. & Sigelman C. K. (1995) Response biases in interviews of individuals with limited mental ability. Journal of Intellectual Disability Research 39, 331–340. Kebbell M. & Hatton C. (1999) People with mental retardation as witnesses in court: a review. Mental Retardation 37, 179–187. Kebbell M. & Wagstaff G. (1992) Face Value? Evaluating the Accuracy of Eyewitness Information. Home Office, London. Kebbell M., Hatton C., Johnson S. D. & O’Kelly C. M. E. (2002) People with learning disabilities as witnesses in court: what questions should lawyers ask? in preparation. Kosslyn S. & Koenig O. (1992) Wet Mind: the New Cognitive Neuroscience. Free Press, New York. Milne R. (1999) Interviewing children with learning disabilities. In: Handbook of the Psychology of Interviewing (eds A. Memon. & R. Bull.), pp. 165–180. Wiley, Chichester. Milne R. & Bull R. (1999) Investigative Interviewing: Psychology and Practice. Wiley, Chichester. Milne R. & Bull R. (2002) Interviewing witnesses with learning disability for legal purposes: a review. British Journal of Learning Disabilities, in press. Milne R., Clare I. C. H. & Bull R. (1999) Using the cognitive interview with adults with mild learning disabilities. Psychology, Crime and Law 5, 81–101. Prosser H. & Bromley J. (1998) Interviewing people with intellectual disabilities. In: Clinical Psychology and People with Intellectual Disabilities (eds E. Emerson, C. Hatton, J. Bromley & A. Caine), pp. 99–113. Wiley, Chichester. Sanders A., Creaton J., Bird S. & Weber L. (1997) Victims with Learning Disabilities: Negotiating the Criminal Justice System. Oxford University Centre for Criminological Research, Oxford.
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Sharrock R. & Gudjonsson G. (1993) Intelligence, previous convictions and interrogative suggestibility: a path analysis of alleged false confession cases. British Journal of Clinical Psychology 32, 169–175. Tully B. & Cahill D. (1984) Police Interviewing of the Mentally Handicapped. Police Foundation, London.
Appendix 1 Adaptation of the GSS (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12)
Did the boy have a sister? Was the front door blue or white? Did the children cross at the traffic lights or the zebra crossing? Was the man in the yellow car driving faster than the speed limit? Was the van driver delivering boxes? Did the lollipop man give the boy the time? Was the boy’s name Jamie? Did the car’s right or left headlight smash in the accident? Was the driver of the yellow car a man? Did the boy drop his lunch box during the accident? Did the boy have a bandage on his head or his arm? Was the boy put on a stretcher?
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