- Email: [email protected]
impulsivity and antisocial personality disorder. Which is the best predictor of false confessions?
Personality and Individual Differences 48 (2010) 720–724
Contents lists available at ScienceDirect
Personality and Individual Differences journal homepage: www.elsevier.com/locate/paid
Inattention, hyperactivity/impulsivity and antisocial personality disorder. Which is the best predictor of false confessions? Gisli H. Gudjonsson a,*, Jon Fridrik Sigurdsson b,c, Emil Einarsson b, Olafur Orn Bragason d, Anna Kristin Newton e a
Department of Psychology, Institute of Psychiatry, King’s College, London, United Kingdom Division of Psychiatry, Landspitali-University Hospital, Reykjavik, Iceland Faculty of Medicine, University of Iceland, Reykjavik, Iceland d The Office of the National Commissioner of the Icelandic Police, Reykjavik, Iceland e The Prison and Probation Administration, Reykjavik, Iceland b c
a r t i c l e
i n f o
Article history: Received 9 November 2009 Received in revised form 6 January 2010 Accepted 12 January 2010 Available online 9 February 2010 Keywords: False confessions Antisocial personality disorder ADHD Inattention Hyperactivity/impulsivity
a b s t r a c t The aim of the study was to investigate the relative importance of Antisocial Personality Disorder (APD) and Attention Deficit Hyperactivity Disorder (ADHD) in predicting a history of false confessions to police. The participants were 90 male prisoners who were interviewed within 10 days of admission to prison. They completed the Mini International Neuropsychiatric Interview and the Wender–Utah Rating Scale (WURS) and DSM-IV-TR Checklist for childhood and adult ADHD symptoms, respectively. Over half of the participants (58%) met criteria for APD, half (50%) had ADHD in childhood and of those 60% were either fully symptomatic or in partial remission of their symptoms. Twenty-two (24%) reported a history of giving false confessions during police interrogation. Adult inattention and hyperactivity symptoms were significantly more common among the false confessors than the other prisoners with high and moderate effect size (1.03 and 0.58), respectively. Binary logistic regression (‘forced entry method’) was used to determine the order of the predictor variables of false confession and the data were entered in three blocks (APD, hyperactivity/impulsivity, and inattention). Inattention was the only remaining significant predictor after controlling for APD and hyperactivity/impulsivity. The findings suggest that inattention is a more powerful predictor of false confession than hyperactivity/impulsivity and APD. Ó 2010 Elsevier Ltd. All rights reserved.
1. Introduction ADHD is a childhood developmental disorder, which consists of three primary symptoms: inattention, hyperactivity and impulsivity (American Psychiatric Association, 2000). The symptoms sometimes persist into adulthood (Young, 2004) and can increase the risk of poor adjustment in adult life if the person is partly or fully symptomatic for ADHD (Young & Gudjonsson, 2006, 2008). ADHD is particularly common among prisoners where approximately 50% of inmates have been screened to have childhood ADHD and of those about half retain full or partial symptoms in adulthood (e.g. Einarsson, Sigurdsson, Gudjonsson, Newton, & Bragason, 2009; Rasmussen, Almvik, & Levander, 2001). Within the criminal justice system, people with ADHD can be psychologically vulnerable or disadvantaged at different stages of the process. This includes more frequent offending and police contact (e.g., Barkley, Fischer, Smallish, & Fletcher, 2004; Young, 2007), * Corresponding author. Address: Department of Psychology, (P.O. Box 78), Institute of Psychiatry, De Crespigny Park, Denmark Hill, London SE5 8AF, England, United Kingdom. E-mail address: [email protected] (G.H. Gudjonsson). 0191-8869/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.paid.2010.01.012
increased risk of false confession during custodial interrogation (Gudjonsson, Sigurdsson, Einarsson, Bragason, & Newton, 2008a), problems with fitness to plead and stand trial (Gudjonsson & Young, 2006), and being involved in more critical incidents in prison (Young et al., 2009). The purpose of the current paper is to investigate the association between ADHD symptoms (inattention versus hyperactivity/impulsivity), antisocial personality disorder and false confessions among prisoners. False confessions typically occur in three different contexts, religion, psychotherapy, and criminal law (Kassin & Gudjonsson, 2004). In this paper we focus on false confessions in the context of criminal law. There is evidence from many separate sources that false confessions to crimes do occur; this includes studies of actual real life cases of wrongful convictions (Drizin & Leo, 2004; Gudjonsson, 2003, 2006), false confessions reported by prison inmates (Gudjonsson & Sigurdsson, 1994; Sigurdsson & Gudjonsson, 1996), suspects detained at police stations (Sigurdsson, Gudjonsson, Einarsson, & Gudjonsson, 2006), and a number of community samples (e.g., Gudjonsson, in press). False confessions are multifaceted in nature and have a variety of causes, but there is evidence that antisocial personality disorder is important in some cases (Gudjonsson, 2003).
G.H. Gudjonsson et al. / Personality and Individual Differences 48 (2010) 720–724
Gudjonsson and Sigurdsson (1994) and Sigurdsson and Gudjonsson (1996) investigated the reporting of false confessions to police by prisoners in Iceland. A discriminant function analysis of the data from the two studies (Sigurdsson & Gudjonsson, 2001) showed that out of 33 predictor variables, the number of previous imprisonments and antisocial personality disorder traits, as measured by the Gough Socialization Scale (Gough, 1960), were the two best predictors of false confessions. They correctly classified 93% of the non-false confessors and 32.3% of the false confessors with an overall classification of 82.7%. The authors interpreted this finding as an indication that false confessions among prisoners were a part of their criminal life style. Gudjonsson et al. (2008a) replicated the two previous Icelandic prison studies, but included measures of childhood and adult ADHD. Out of the 90 prisoners, 22 (24%) reported a history of false confession. Out of the 27 (30%) prisoners who met childhood criteria for ADHD and were currently symptomatic for ADHD (i.e., either partially or fully symptomatic), 11 (41%) reported a history of a false confession in contrast to 11 (18%) of the 63 other prisoners. The findings suggested that adults with ADHD were more susceptible to making a false confession than other prisoners. The false confessions were mainly made to property offences (62%), drug offences (29%) and traffic violations (18%). The reasons given for making a false confession to the police were overlapping, but mainly involved wanting to leave the police station, avoid custody, or protect the real perpetrator (i.e., a peer or a friend). The purpose of the present study is to extend the analysis of the data in the Gudjonsson et al. (2008a) study to include a measure of antisocial personality disorder (i.e., Mini International Neuropsychiatric Interview; Sheehan et al., 1998) and to investigate separately the effects of inattention and hyperactivity/impulsivity. This has never been investigated previously. If Sigurdsson and Gudjonsson (2001) are correct that a history of false confessions among serious offenders is a part of their criminal life style, then it would be predicted that antisocial personality and hyperactivity/impulsivity would be better predictors of false confession than inattention. Indeed, it is the hyperactivity/impulsivity part of ADHD, which is the most direct predictor of offending and frequent police contact among young adults (Barkley et al., 2004). 2. Methodology 2.1. Participants The participants were 90 Icelandic male prisoners who were serving sentences for criminal offences, mainly property, drug, and driving offences. They had a mean age of 30 years (SD = 9.8, range 19–56). 2.2. Measures 2.2.1. Wender–Utah Rating Scale (WURS; Ward, Wender, & Reimherr, 1993) The WURS is a 25-item measure of childhood symptoms of ADHD. Each of the items is rated on a five point rating scale of frequency of symptoms (ranging from 0 = ‘not at all’ to 4 = ‘very much’). The total score on the WURS ranges between 0 and 100. A score of P46 has been shown to correctly classify 86% of participants with ADHD and 99% ‘normal’ participants (Ward et al., 1993). 2.2.2. Diagnostic Statistical Manual IV Checklist of Symptoms (American Psychiatric Association, 2000) The DSM-IV-TR Checklist of Symptoms consists of 18 items rated in relation to symptoms of ADHD, which was taken from the published version of the Manual. It corresponds with the
721
DSM-IV criteria. Nine items involve problems with inattention and nine items relate to problems with hyperactivity/impulsiveness. Each item is scored on a 3-point rating scale (0 = never, 1 = sometimes, 2 = often). The possible total score on the DSM-IV Checklist ranges between 0 and 36. Participants were asked to complete the items in relation to symptoms they had experienced during the previous six months. ADHD adult criteria were classified in the present study as six or more inattentive items (rated as ‘often’) and six or more hyperactive/impulsive items (rates as ‘often’), which means that they met the screening criteria for ADHD. 2.2.3. Mini International Neuropsychiatric Interview (MINI; Sheehan et al., 1998, 1997) This consists of a structured diagnostic interview, comprised of 120 questions, and assesses the presence of the 19 most common DSM-IV and ICD-10 disorders, 17 Axis I disorders, one Axis II disorder (antisocial personality disorder) and suicidal ideation/attempts. The questions are answered either ‘‘yes” or ‘‘no” and normally take about 15–20 min to administer. The MINI provides a diagnosis of current symptoms of mental disorders, as well as past and lifetime diagnoses where it is clinically relevant for the current diagnosis. In the current paper, we only present the findings in relation to the antisocial personality (APD) scale. The MINI has been shown to have good inter-rater and test–retest reliabilities and good correlations to both the SCID and the CIDI (Pinninti, Madison, Musser, & Rissmiller, 2003; Sheehan et al., 1998). 2.3. Background questions The participants were briefly questioned about their background prior to completing the tests. This included asking them questions about their age, social, educational and offending background, and whether they have ever made a false confession during a police interrogation. We used the wording of the questions as the one used in the previous prison studies by Gudjonsson and Sigurdsson (1994) and Sigurdsson and Gudjonsson (1996). The key question asked was: ‘‘Have you ever made a confession to the police about a crime you did not commit?” The answer was reported as ‘yes’ or ‘no’. Those participants who reported having made a false confession were asked about the offence they had falsely confessed to and the reason for having made the false confession (see Gudjonsson et al., 2008a). 2.4. Procedure The prisoners were all tested within 10 days of admission to the prison. They were all tested individually after giving a written consent for their participation in the study. The participants were told that the purpose of the study was to investigate problems with attention and hyperactivity and their relationship with personality and mental health problems. The study was approved by the National Bioethics Committee, the Icelandic Data Protection Authority, and the Prison and Probation Administration. 3. Results Table 1 shows the differences in the ADHD childhood and adult scores between the 22 false confessors and the other participants. The WURS scores did not differ significantly between the two groups. Significant group differences emerged for the three DSMIV-TR adult scores with the strongest (‘large’) effect size being for
722
G.H. Gudjonsson et al. / Personality and Individual Differences 48 (2010) 720–724
Table 1 The differences in the ADHD scores on the Wender–Utah Scale (childhood symptoms) and the DSM-IV-TR ADHD Scale (adult symptoms) between the false confessors and non-false confessors.
* **
ADHD measures
False confessors Mean (SD) (N)
Non-false confessors Mean (SD) (N)
t-value
Effect size
Wender–Utah Scale DSM-IV Checklist Inattention Hyperactivity/ impulsivity
48.3 (22.1) (22) 19.2 (6.4) (22) 11.5 (3.9) (22) 7.7 (3.8) (22)
48.1 (22.1) (68) 12.4 (8.3) (67) 7.0 (4.8) (67) 5.4 (4.1) (67)
0.03 3.53** 3.97** 2.33*
0.01 0.92 1.03 0.58
p < 0.05. p < 0.001.
the total (0.92) and inattention (1.03) scales and ‘medium’ effect size (0.58) for hyperactivity/impulsivity (Cohen’s d; Cohen, 1988). Table 2 gives the categorical figures for APD and the two ADHD measures. Fifty-two (58%) of the participants met the criteria for APD on the MINI. The hyperactivity/impulsivity and inattention scores were categorised into ‘high’ and ‘low/average’ scores by classifying those who scored more than one standard deviation above the mean on each measure as ‘high’. This resulted in a score of 10 or above on hyperactivity/impulsivity (N = 18) and 13 or above on inattention (N = 19) being categorised as ‘high’. Table 2 shows that for APD, hyperactivity/impulsivity, and impulsivity, 34.6%, 33.3% and 52.6%, respectively, had a history of false confession. The corresponding false confession percentages for those who did not meet the diagnostic criteria in the three groups were 10.5%, 22.5%, and 17.1%. The APD and inattention diagnostic criteria were significantly related to false confessions with the Odds Ratios being 1.64 and 3.38, respectively, suggesting that inattention was a better predictor of false confession than APD. No significant relationship was found between false confession and hyperactivity/ impulsivity. In order to investigate which of the three variables, APD, hyperactivity/impulsivity and inattention, was most influential in pre-
dicting false confession a logistic regression analysis was performed. The results are shown in Table 3. The outcome variable was whether or not the participant had a history of false confession. A forced entry method was used to enter the data (Field, 2003). In order to explore the individual contribution of each of the three variables, the three variables were entered in three steps in the following order in accordance with our hypothesis: APD, hyperactivity/impulsivity, and inattention. APD was a significant predictor at step one (R2 = 0.11), hyperactivity/impulsivity did not add much to the variance in the false confession rate in step two (R2 = 0.12), and inattention added substantially to the variance (R2 = 0.19) and remained the single best predictor (Wald = 4.66, Odds Ratio 4.64). The final model correctly classified 98.5% of the non-false confessors and 31.8% of the false confessors with an overall classification of 82.0%.
4. Discussion The relationship between false confessions and ADHD inattention and hyperactivity/impulsivity symptoms was investigated in two ways. Firstly, by comparing the mean childhood scores, measured by the WURS, and adult (measured by the DSM-IV-TR) ADHD scores, between the false confessors and the other prisoners by the use of t-tests and effect size using Cohen’s d (i.e., the ADHD measures were used as dimensions). Secondly, by a logistic regression analysis, where the dependent measure was false confessors versus non-false confessors, and the independent measures (ADP, hyperactivity/impulsivity, and inattention), used as categorical scores, were entered in three steps in order to study their individual effects. The three predictors were binary variables, where the hyperactivity/impulsivity and inattention measures were categorised into those participants who were either symptomatic or not symptomatic for: (a) hyperactivity/ impulsivity; and (b) inattention, defined as those who scored more than one standard deviation above the mean on each of the two scales.
Table 2 The relationship between a history of false confession, Antisocial Personality Disorder (APD), and being symptomatic for hyperactivity/impulsivity and inattention (categorical classification of all variables). APD Yes False confessors
No
18/52 (34.6%) 4/38 (10.5%) X2 = 6.90, p < 0.01 OR = 1.64, CI = 1.20–2.23
ADHD-hyperactivity/impulsivity
ADHD-inattention
Yes
No
Yes
6/18 (33.3%) X2 = 0.90, n.s.
16/71 (22.5%)
10/19 (52.6%) 12/70 (17.1%) X2 = 10.11, p < 0.001 OR = 3.38, CI = 1.58–7.24
No
Table 3 Summary of the logistic (binary) regression for Antisocial Personality Disorder (APD), ADHD hyperactivity/impulsivity and inattention in predicting false confession. Explanatory variables
Exp(B)
CI (95%)
Block 1 APD 1.47 (0.60) 5.95* Block 1 statistics: R2 = 0.11 (Nagelkerke). Block v2 = 7.11**. Model v2 = 7.11**. Overall classification 75.3%
B (S.E.)
Wald
4.37
1.34–14.28
Block 2 APD 1.43 (0.61) 5.48* Hyperactivity/impulsivity 0.27 (0.60) 0.20 Block 2 statistics: R2 = 0.12 (Nagelkerke). Block v2 = 0.19. Model v2 = 7.30*. Overall classification 75.3%
4.19 1.30
1.26–13.90 0.40–4.22
Block 3 APD 1.03 (0.65) 2.51 2.81 Hyperactivity/impulsivity 0.50 (0.74) 0.46 0.61 4.64 ADHD-inattention 1.53 (0.71) 4.66* Block 3 statistics: R2 = 0.19 (Nagelkerke). Block v2 = 5.02*. Model v2 = 12.32**. Overall classification 82.0%, 31.8% for false confessors and * **
p < 0.05. p < 0.01.
0.78–10.05 0.14–2.60 1.15–18.67 98.5% for controls
G.H. Gudjonsson et al. / Personality and Individual Differences 48 (2010) 720–724
Both methods produced the same results; false confessions were more strongly associated with inattention than hyperactivity/impulsivity. Indeed, the binary logistic regression showed that after entering APD, hyperactivity/impulsivity was not a significant predictor of false confession, and after inattention was entered in the third step, inattention remained the single best predictor after controlling for APD and hyperactivity/impulsivity. The final model correctly classified 98.5% of the non-false confessors and 31.8% of the false confessors with an overall classification of 82.0%, which is almost identical to the classification of false confessors found by Sigurdsson and Gudjonsson (2001) using a large range of psychological and criminological measures. The data from both studies suggest an extremely high level of specificity (i.e., correct identification non-false confessors), but only a modest level of sensitivity (i.e., identification of false confessors). The finding that a diagnosis of APD significantly predicted a preexisting history of false confession is consistent with the literature (Gudjonsson, 2003; Sigurdsson & Gudjonsson, 1996; Sigurdsson & Gudjonsson, 2001). Gudjonsson, Sigurdsson, Bragason, Einarsson, and Valdimarsdottir (2004) found among a large sample of college students that antisocial personality traits, measured by the Gough Socialisation Scale (Gough, 1960) and the Psychoticism dimension of the Eysenck Personality Questionnaire (EPQ; Eysenck & Eysenck, 1975), were associated with false confessions. The authors suggested that the reason was that persons with personality disorder traits lie to police during questioning for instrumental gains and have disregard for the consequences of their deception. Another possibility is that people with antisocial personality traits are more involved in crime and get arrested and questioned more often by police, which leaves them susceptible to making a false confession (Gudjonsson, Sigurdsson, Asgeirsdottir, & Sigfusdottir, 2006; Gudjonsson, Sigurdsson, & Sigfusdottir, 2009; Gudjonsson, Sigurdsson, Sigfusdottir, & Asgeirsdottir, 2008b). It may be that conduct disorder and ADHD increase the likelihood that they get involved with offending and police questioning (Barkley et al., 2004). The present findings provide a new insight into the nature of false confessions. APD and ADHD are significantly associated with false confession, but the present findings demonstrate that it is specifically the inattention component of ADHD which is the single best predictor of false confessions. It is even more powerful than APD. This is a surprising finding and requires an explanation. What is it that mediates the relationship between inattention and false confession? The key is likely to be the anxiety and disorganisational aspect of ADHD. Gudjonsson, Sigurdsson, Gudmundsdottir, Sigurjonsdottir, and Smari (in press) have shown that the core component of maladaptive personality associated with the ADHD inattention symptoms is impaired capacity to set and achieve realistic goals. Maedgen and Carlson (2000) found that children with ADHD had impaired social functioning in comparison with controls, but important differences existed between ADHD subgroups. The ADHD combined type was significantly impaired both in terms of social performance and emotional regulation, whereas the predominantly inattentive type only displayed deficits in social knowledge and social passivity. It may be the social passivity part of the inattentive ADHD type, which appears a similar construct to that measured in adults by the Gudjonsson Compliance Scale (GCS; Gudjonsson, 1989, 1997) and their disorganization in day to day living, interfere with their ability to cope with police questioning and detention and makes it difficult for them to resist the temptation to take the blame for a peer (Gudjonsson, Sigurdsson, & Einarsson, 2007). In future studies, it would be important to measure social passivity and compliance and investigate to what extent they may mediate the relationship between inattention and false confessions. It would be expected from the findings in the present study that compliance would be better correlated with inattention
723
than hyperactivity/impulsivity. Persons diagnosed with ADHD have not been found to be unduly suggestible during questioning, but their general vagueness and disorganisation when questioned may leave them impaired in coping with police questioning (Gudjonsson, Young, & Bramham, 2007). The current findings have important implications for habitual offenders, some of whom undoubtedly have ADHD when interviewed by police (Sigurdsson, Gudjonsson, Einarsson, & Gudjonsson, 2006). In the present study, false confessions were only found to be related to ADHD symptoms in adulthood (i.e., during the previous six months at the time of the study). The mean scores on the WURS did not differentiate between the false confessors and other prisoners. This could be due to either the limitations of the instruments (i.e., there is no differentiation between the hyperactivity/impulsivity and inattention symptoms) or that the current (adult) symptoms rather than the childhood symptoms are only relevant to false confessions. One possibility is that childhood ADHD symptoms, particularly when accompanied by conduct disorder and substance use, lead to delinquency and adult offending (Gudjonsson, Young, & Wells, under review), but it is the residual inattention that leaves them additionally vulnerable to giving a false confession to the police during questioning. The main limitation of the present study is the small number of cases of false confessions, which impacts on power. This is perhaps most evident in the logistic regression with regard to APD and hyperactivity/impulsivity categorisation. The second limitation is that the reporting of false confessions could not be independently corroborated. Those participants who claimed to have made a false confession were asked specific follow-up questions about the false confession and this also ensured that they had properly understood the question regarding false confessions. Thirdly, the ADHD symptoms were based on self-reported DSM screens, but these have been found to be highly correlated with those found in a diagnostic interview (Magnusson et al., 2006; Murphy & Schachar, 2000). Fourthly, only male participants were included in the study. The study of Sigurdsson and Gudjonsson (1996) conducted among a similar group of prisoners in the mid-1990s found that 15% of the false confessors were female. They differed from the male false confessors in terms of the motivation for making the false confession (i.e., all of them had allegedly made a false confession to protect somebody else, in contrast to only about half of the male false confessors). The rate of ADHD among female prisoners is very high (Rosler, Retz, Yaqoobi, Burg, & Retz-Junginer, 2009), which means that future research into the relationship between ADHD symptoms and false confessors should whenever possible focus on both males and females. In spite of the limitations of the present study, the findings are clear. Inattention is a more powerful predictor of false confession than hyperactivity/impulsivity and APD. Future studies into ADHD and false confessions should separate the inattention and hyperactivity/impulsivity items and investigate the specific mechanisms involved. Acknowledgement The authors would like to thank Maria Hronn Nikulasdottir for computing the data and the Nordic Council of Criminology for funding the study. References American Psychiatric Association (2000). Diagnostic and statistical manual of mental disorders (DSM-IV-TR). Washington, DC: American Psychiatric Association. Barkley, R. A., Fischer, M., Smallish, L., & Fletcher, K. (2004). Young adult follow-up of hyperactive children: Antisocial activities and drug use. Journal of Child Psychology and Psychiatry, 45, 195–211.
724
G.H. Gudjonsson et al. / Personality and Individual Differences 48 (2010) 720–724
Cohen, J. (1988). Statistical power analysis for the behavioural sciences. Hillsdale, NJ: Erlbaum. Drizin, S. A., & Leo, R. A. (2004). The problem of false confessions in the post-DNA world. North Carolina Law Review, 82, 891–1007. Einarsson, E., Sigurdsson, J. F., Gudjonsson, G. H., Newton, A. K., & Bragason, O. O. (2009). Screening for attention deficit hyperactivity disorder and co-morbid mental disorders among prison inmates. Nordic Journal of Psychiatry, 63, 361–367. Eysenck, H. J., & Eysenck, S. B. G. (1975). Manual of the Eysenck personality questionnaire. London: Hodder and Stoughton. Field, A. (2003). Discovering statistics using SPSS. London: Sage. Gough, H. H. (1960). Theory and measurement of socialization. Journal of Consulting and Clinical Psychology, 24, 23–30. Gudjonsson, G. H. (1989). Compliance in an interrogation situation: A new scale. Personality and Individual Differences, 10, 535–540. Gudjonsson, G. H. (1997). The Gudjonsson suggestibility scales manual. Hove: Psychology Press. Gudjonsson, G. H. (2003). The psychology of interrogations and confessions: A handbook. John Wiley: Chichester. Gudjonsson, G. H. (in press). The psychology of false confessions: A review of the current evidence. In G. Daniel Lassiter & Christian A. Meissner (Eds.), Interrogations and confessions: Research, practice, and policy. New York: American Psychological Association. Gudjonsson, G. H. (2006). Disputed confessions and miscarriages of justice in Britain: Expert psychological and psychiatric evidence in court of appeal. The Manitoba Law Journal, 31, 489–521. Gudjonsson, G. H., & Sigurdsson, J. F. (1994). How frequently do false confessions occur? An empirical study among prison inmates. Psychology, Crime and Law, 1, 21–26. Gudjonsson, G. H., Sigurdsson, J. F., Asgeirsdottir, B. B., & Sigfusdottir, I. D. (2006). Custodial interrogation, false confession and individual differences. A national study among Icelandic youth. Personality and Individual Differences, 41, 49–59. Gudjonsson, G. H., Sigurdsson, J. F., Bragason, O. O., Einarsson, E., & Valdimarsdottir, E. B. (2004). Confessions and Denials and the relationship with personality. Legal and Criminological Psychology, 9, 121–133. Gudjonsson, G. H., Sigurdsson, J. F., & Einarsson, E. (2007). Taking blame for antisocial acts and its relationship with personality. Personality and Individual Differences, 43, 3–13. Gudjonsson, G. H., Sigurdsson, J. F., Einarsson, E., Bragason, O. O., & Newton, A. K. (2008a). Interrogative suggestibility, compliance and false confessions among prisoners and their relationship with attention deficit hyperactivity disorder (ADHD) symptoms. Psychological Medicine, 38, 1037–1044. Gudjonsson, G. H., Sigurdsson, J. F., Gudmundsdottir, H. B., Sigurjonsdottir, S., & Smari, J. (in press). The relationship between ADHD symptoms in college students and core components of maladaptive personality. Personality and Individual Differences. doi:10.1016/j.paid.2009.12.015. Gudjonsson, G. H., Sigurdsson, J. F., & Sigfusdottir, I. D. (2009). Interrogations and false confessions among adolescents in seven countries in Europe. What background and psychological factors best discriminate between false confessors and non-false confessors? Psychology, Crime and Law, 15, 711–728. Gudjonsson, G. H., Sigurdsson, J. F., Sigfusdottir, I. D., & Asgeirsdottir, B. B. (2008b). False confessions and individual differences. The importance of victimization among youth. Personality and Individual Differences, 45, 801–805. Gudjonsson, G. H., & Young, S. (2006). An overlooked vulnerability in a defendant: Attention deficit hyperactivity disorder and a miscarriage of justice. Legal and Criminological Psychology, 11, 211–218. Gudjonsson, G. H., Young, S., & Bramham, J. (2007). Interrogative suggestibility in adults diagnosed with attention-deficit hyperactivity disorder (ADHD). A potential vulnerability during police questioning. Personality and Individual Differences, 43, 737–745.
Gudjonsson, G. H., Young, S., & Wells, J. (under review). The role of Attention Deficit Hyperactivity Disorder (ADHD) and substance use in the offending history of prisoners. Kassin, S. M., & Gudjonsson, G. H. (2004). The psychology of confessions. A review of the literature and issues. Psychological Science in the Public Interest, 5, 33–67. Maedgen, J. W., & Carlson, C. L. (2000). Social functioning and emotional regulation in the attention deficit hyperactivity disorder subtypes. Journal of Clinical Child Psychology, 29, 30–42. Magnusson, P., Smari, J., Sigurdardottir, D., Baldursson, G., Sigmundsson, J., Kristjansson, K., et al. (2006). Validity of self-report and informant rating scales of adult ADHD symptoms in comparison with a semistructured diagnostic interview. Journal of Attention Disorders, 9, 494–503. Murphy, P., & Schachar, R. (2000). Use of self-ratings in the assessment of symptoms of Attention Deficit Hyperactivity Disorder in adults. American Journal of Psychiatry, 157, 1156–1159. Pinninti, N. R., Madison, H., Musser, E., & Rissmiller, D. (2003). MINI International Neuropsychiatric Schedule: Clinical utility and patient acceptance. European Psychiatry, 18, 361–364. Rasmussen, K., Almvik, M. R., & Levander, S. (2001). Attention deficit hyperactivity disorder, reading disability, and personality disorders in a prison population. The Journal of the American Academy of Psychiatry and the Law, 29, 186–193. Rosler, M., Retz, W., Yaqoobi, K., Burg, E., & Retz-Junginer, P. (2009). Attention deficit/hyperactivity disorder in female offenders: Prevalence, psychiatric comorbidity and psychosocial implications. European Archives of Psychiatry in Clinical Neuroscience, 259, 98–105. Sheehan, D. V., Lecrubier, Y., Sheehan, K. H., Amorin, P., Janavs, J., Weiller, E., et al. (1998). The Mini-International Neuropsychiatric Interview (M.I.N.I.): The development and validation of a structured diagnostic psychiatric interview for DSM-IV and ICD-10. Journal of Clinical Psychiatry, 59, 22–33. Sheehan, D. V., Lecrubier, Y., Sheehan, K. H., Janavs, J., Weiller, E., Keskiner, A., et al. (1997). The validity of the Mini International Neuropsychiatric Interview (MINI) according to the SCID-P and its reliability. European Psychiatry, 12, 232–241. Sigurdsson, J. F., & Gudjonsson, G. H. (1996). Psychological characteristics of ‘false confessors’. A study among Icelandic prison inmates and juvenile offenders. Personality and Individual Differences, 20, 321–329. Sigurdsson, J. F., & Gudjonsson, G. H. (2001). False confessions: The relative importance of psychological, criminological and substance abuse variables. Psychology, Crime and Law, 7, 275–289. Sigurdsson, J. F., Gudjonsson, G. H., Einarsson, E., & Gudjonsson, G. (2006). Differences in personality and mental state between suspects and witnesses immediately after being interviewed by the police. Psychology, Crime and Law, 12, 619–628. Ward, M. F., Wender, P. H., & Reimherr, M. D. (1993). The Wender Utah Rating Scale: An aid in the retrospective diagnosis of childhood Attention Deficit Hyperactivity Disorder. American Journal of Psychiatry, 150, 885–890. Young, S. (2004). The YAQ-S AND YAQ-I: The development of self and informant questionnaires reporting on current adult ADHD symptomatology, comorbid and associated problems. Personality and Individual Differences, 36, 1211–1224. Young, S. (2007). Forensic aspects of ADHD. In Ml. Fitzarald, M. Bellgrove, & M. Gill (Eds.), Handbook of attention deficit hyperactivity disorder (pp. 91–108). Chichester: John Wiley & Sons. Young, S., & Gudjonsson, G. (2006). ADHD symptomatology and its relationship with emotional, social and delinquency problems. Psychology, Crime and Law, 12, 463–471. Young, S., & Gudjonsson, G. H. (2008). Growing out of ADHD: The relationship between functioning and symptoms. Journal of Attention Disorder, 12, 162–169. Young, S., Gudjonsson, G. H., Wells, J., Asherson, P., Theobald, D., Oliver, B., et al. (2009). Attention Deficit Hyperactivity Disorder and critical incidents in a Scottish prison population. Personality and Individual Difference, 46, 265–269.
Contents lists available at ScienceDirect
Personality and Individual Differences journal homepage: www.elsevier.com/locate/paid
Inattention, hyperactivity/impulsivity and antisocial personality disorder. Which is the best predictor of false confessions? Gisli H. Gudjonsson a,*, Jon Fridrik Sigurdsson b,c, Emil Einarsson b, Olafur Orn Bragason d, Anna Kristin Newton e a
Department of Psychology, Institute of Psychiatry, King’s College, London, United Kingdom Division of Psychiatry, Landspitali-University Hospital, Reykjavik, Iceland Faculty of Medicine, University of Iceland, Reykjavik, Iceland d The Office of the National Commissioner of the Icelandic Police, Reykjavik, Iceland e The Prison and Probation Administration, Reykjavik, Iceland b c
a r t i c l e
i n f o
Article history: Received 9 November 2009 Received in revised form 6 January 2010 Accepted 12 January 2010 Available online 9 February 2010 Keywords: False confessions Antisocial personality disorder ADHD Inattention Hyperactivity/impulsivity
a b s t r a c t The aim of the study was to investigate the relative importance of Antisocial Personality Disorder (APD) and Attention Deficit Hyperactivity Disorder (ADHD) in predicting a history of false confessions to police. The participants were 90 male prisoners who were interviewed within 10 days of admission to prison. They completed the Mini International Neuropsychiatric Interview and the Wender–Utah Rating Scale (WURS) and DSM-IV-TR Checklist for childhood and adult ADHD symptoms, respectively. Over half of the participants (58%) met criteria for APD, half (50%) had ADHD in childhood and of those 60% were either fully symptomatic or in partial remission of their symptoms. Twenty-two (24%) reported a history of giving false confessions during police interrogation. Adult inattention and hyperactivity symptoms were significantly more common among the false confessors than the other prisoners with high and moderate effect size (1.03 and 0.58), respectively. Binary logistic regression (‘forced entry method’) was used to determine the order of the predictor variables of false confession and the data were entered in three blocks (APD, hyperactivity/impulsivity, and inattention). Inattention was the only remaining significant predictor after controlling for APD and hyperactivity/impulsivity. The findings suggest that inattention is a more powerful predictor of false confession than hyperactivity/impulsivity and APD. Ó 2010 Elsevier Ltd. All rights reserved.
1. Introduction ADHD is a childhood developmental disorder, which consists of three primary symptoms: inattention, hyperactivity and impulsivity (American Psychiatric Association, 2000). The symptoms sometimes persist into adulthood (Young, 2004) and can increase the risk of poor adjustment in adult life if the person is partly or fully symptomatic for ADHD (Young & Gudjonsson, 2006, 2008). ADHD is particularly common among prisoners where approximately 50% of inmates have been screened to have childhood ADHD and of those about half retain full or partial symptoms in adulthood (e.g. Einarsson, Sigurdsson, Gudjonsson, Newton, & Bragason, 2009; Rasmussen, Almvik, & Levander, 2001). Within the criminal justice system, people with ADHD can be psychologically vulnerable or disadvantaged at different stages of the process. This includes more frequent offending and police contact (e.g., Barkley, Fischer, Smallish, & Fletcher, 2004; Young, 2007), * Corresponding author. Address: Department of Psychology, (P.O. Box 78), Institute of Psychiatry, De Crespigny Park, Denmark Hill, London SE5 8AF, England, United Kingdom. E-mail address: [email protected] (G.H. Gudjonsson). 0191-8869/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.paid.2010.01.012
increased risk of false confession during custodial interrogation (Gudjonsson, Sigurdsson, Einarsson, Bragason, & Newton, 2008a), problems with fitness to plead and stand trial (Gudjonsson & Young, 2006), and being involved in more critical incidents in prison (Young et al., 2009). The purpose of the current paper is to investigate the association between ADHD symptoms (inattention versus hyperactivity/impulsivity), antisocial personality disorder and false confessions among prisoners. False confessions typically occur in three different contexts, religion, psychotherapy, and criminal law (Kassin & Gudjonsson, 2004). In this paper we focus on false confessions in the context of criminal law. There is evidence from many separate sources that false confessions to crimes do occur; this includes studies of actual real life cases of wrongful convictions (Drizin & Leo, 2004; Gudjonsson, 2003, 2006), false confessions reported by prison inmates (Gudjonsson & Sigurdsson, 1994; Sigurdsson & Gudjonsson, 1996), suspects detained at police stations (Sigurdsson, Gudjonsson, Einarsson, & Gudjonsson, 2006), and a number of community samples (e.g., Gudjonsson, in press). False confessions are multifaceted in nature and have a variety of causes, but there is evidence that antisocial personality disorder is important in some cases (Gudjonsson, 2003).
G.H. Gudjonsson et al. / Personality and Individual Differences 48 (2010) 720–724
Gudjonsson and Sigurdsson (1994) and Sigurdsson and Gudjonsson (1996) investigated the reporting of false confessions to police by prisoners in Iceland. A discriminant function analysis of the data from the two studies (Sigurdsson & Gudjonsson, 2001) showed that out of 33 predictor variables, the number of previous imprisonments and antisocial personality disorder traits, as measured by the Gough Socialization Scale (Gough, 1960), were the two best predictors of false confessions. They correctly classified 93% of the non-false confessors and 32.3% of the false confessors with an overall classification of 82.7%. The authors interpreted this finding as an indication that false confessions among prisoners were a part of their criminal life style. Gudjonsson et al. (2008a) replicated the two previous Icelandic prison studies, but included measures of childhood and adult ADHD. Out of the 90 prisoners, 22 (24%) reported a history of false confession. Out of the 27 (30%) prisoners who met childhood criteria for ADHD and were currently symptomatic for ADHD (i.e., either partially or fully symptomatic), 11 (41%) reported a history of a false confession in contrast to 11 (18%) of the 63 other prisoners. The findings suggested that adults with ADHD were more susceptible to making a false confession than other prisoners. The false confessions were mainly made to property offences (62%), drug offences (29%) and traffic violations (18%). The reasons given for making a false confession to the police were overlapping, but mainly involved wanting to leave the police station, avoid custody, or protect the real perpetrator (i.e., a peer or a friend). The purpose of the present study is to extend the analysis of the data in the Gudjonsson et al. (2008a) study to include a measure of antisocial personality disorder (i.e., Mini International Neuropsychiatric Interview; Sheehan et al., 1998) and to investigate separately the effects of inattention and hyperactivity/impulsivity. This has never been investigated previously. If Sigurdsson and Gudjonsson (2001) are correct that a history of false confessions among serious offenders is a part of their criminal life style, then it would be predicted that antisocial personality and hyperactivity/impulsivity would be better predictors of false confession than inattention. Indeed, it is the hyperactivity/impulsivity part of ADHD, which is the most direct predictor of offending and frequent police contact among young adults (Barkley et al., 2004). 2. Methodology 2.1. Participants The participants were 90 Icelandic male prisoners who were serving sentences for criminal offences, mainly property, drug, and driving offences. They had a mean age of 30 years (SD = 9.8, range 19–56). 2.2. Measures 2.2.1. Wender–Utah Rating Scale (WURS; Ward, Wender, & Reimherr, 1993) The WURS is a 25-item measure of childhood symptoms of ADHD. Each of the items is rated on a five point rating scale of frequency of symptoms (ranging from 0 = ‘not at all’ to 4 = ‘very much’). The total score on the WURS ranges between 0 and 100. A score of P46 has been shown to correctly classify 86% of participants with ADHD and 99% ‘normal’ participants (Ward et al., 1993). 2.2.2. Diagnostic Statistical Manual IV Checklist of Symptoms (American Psychiatric Association, 2000) The DSM-IV-TR Checklist of Symptoms consists of 18 items rated in relation to symptoms of ADHD, which was taken from the published version of the Manual. It corresponds with the
721
DSM-IV criteria. Nine items involve problems with inattention and nine items relate to problems with hyperactivity/impulsiveness. Each item is scored on a 3-point rating scale (0 = never, 1 = sometimes, 2 = often). The possible total score on the DSM-IV Checklist ranges between 0 and 36. Participants were asked to complete the items in relation to symptoms they had experienced during the previous six months. ADHD adult criteria were classified in the present study as six or more inattentive items (rated as ‘often’) and six or more hyperactive/impulsive items (rates as ‘often’), which means that they met the screening criteria for ADHD. 2.2.3. Mini International Neuropsychiatric Interview (MINI; Sheehan et al., 1998, 1997) This consists of a structured diagnostic interview, comprised of 120 questions, and assesses the presence of the 19 most common DSM-IV and ICD-10 disorders, 17 Axis I disorders, one Axis II disorder (antisocial personality disorder) and suicidal ideation/attempts. The questions are answered either ‘‘yes” or ‘‘no” and normally take about 15–20 min to administer. The MINI provides a diagnosis of current symptoms of mental disorders, as well as past and lifetime diagnoses where it is clinically relevant for the current diagnosis. In the current paper, we only present the findings in relation to the antisocial personality (APD) scale. The MINI has been shown to have good inter-rater and test–retest reliabilities and good correlations to both the SCID and the CIDI (Pinninti, Madison, Musser, & Rissmiller, 2003; Sheehan et al., 1998). 2.3. Background questions The participants were briefly questioned about their background prior to completing the tests. This included asking them questions about their age, social, educational and offending background, and whether they have ever made a false confession during a police interrogation. We used the wording of the questions as the one used in the previous prison studies by Gudjonsson and Sigurdsson (1994) and Sigurdsson and Gudjonsson (1996). The key question asked was: ‘‘Have you ever made a confession to the police about a crime you did not commit?” The answer was reported as ‘yes’ or ‘no’. Those participants who reported having made a false confession were asked about the offence they had falsely confessed to and the reason for having made the false confession (see Gudjonsson et al., 2008a). 2.4. Procedure The prisoners were all tested within 10 days of admission to the prison. They were all tested individually after giving a written consent for their participation in the study. The participants were told that the purpose of the study was to investigate problems with attention and hyperactivity and their relationship with personality and mental health problems. The study was approved by the National Bioethics Committee, the Icelandic Data Protection Authority, and the Prison and Probation Administration. 3. Results Table 1 shows the differences in the ADHD childhood and adult scores between the 22 false confessors and the other participants. The WURS scores did not differ significantly between the two groups. Significant group differences emerged for the three DSMIV-TR adult scores with the strongest (‘large’) effect size being for
722
G.H. Gudjonsson et al. / Personality and Individual Differences 48 (2010) 720–724
Table 1 The differences in the ADHD scores on the Wender–Utah Scale (childhood symptoms) and the DSM-IV-TR ADHD Scale (adult symptoms) between the false confessors and non-false confessors.
* **
ADHD measures
False confessors Mean (SD) (N)
Non-false confessors Mean (SD) (N)
t-value
Effect size
Wender–Utah Scale DSM-IV Checklist Inattention Hyperactivity/ impulsivity
48.3 (22.1) (22) 19.2 (6.4) (22) 11.5 (3.9) (22) 7.7 (3.8) (22)
48.1 (22.1) (68) 12.4 (8.3) (67) 7.0 (4.8) (67) 5.4 (4.1) (67)
0.03 3.53** 3.97** 2.33*
0.01 0.92 1.03 0.58
p < 0.05. p < 0.001.
the total (0.92) and inattention (1.03) scales and ‘medium’ effect size (0.58) for hyperactivity/impulsivity (Cohen’s d; Cohen, 1988). Table 2 gives the categorical figures for APD and the two ADHD measures. Fifty-two (58%) of the participants met the criteria for APD on the MINI. The hyperactivity/impulsivity and inattention scores were categorised into ‘high’ and ‘low/average’ scores by classifying those who scored more than one standard deviation above the mean on each measure as ‘high’. This resulted in a score of 10 or above on hyperactivity/impulsivity (N = 18) and 13 or above on inattention (N = 19) being categorised as ‘high’. Table 2 shows that for APD, hyperactivity/impulsivity, and impulsivity, 34.6%, 33.3% and 52.6%, respectively, had a history of false confession. The corresponding false confession percentages for those who did not meet the diagnostic criteria in the three groups were 10.5%, 22.5%, and 17.1%. The APD and inattention diagnostic criteria were significantly related to false confessions with the Odds Ratios being 1.64 and 3.38, respectively, suggesting that inattention was a better predictor of false confession than APD. No significant relationship was found between false confession and hyperactivity/ impulsivity. In order to investigate which of the three variables, APD, hyperactivity/impulsivity and inattention, was most influential in pre-
dicting false confession a logistic regression analysis was performed. The results are shown in Table 3. The outcome variable was whether or not the participant had a history of false confession. A forced entry method was used to enter the data (Field, 2003). In order to explore the individual contribution of each of the three variables, the three variables were entered in three steps in the following order in accordance with our hypothesis: APD, hyperactivity/impulsivity, and inattention. APD was a significant predictor at step one (R2 = 0.11), hyperactivity/impulsivity did not add much to the variance in the false confession rate in step two (R2 = 0.12), and inattention added substantially to the variance (R2 = 0.19) and remained the single best predictor (Wald = 4.66, Odds Ratio 4.64). The final model correctly classified 98.5% of the non-false confessors and 31.8% of the false confessors with an overall classification of 82.0%.
4. Discussion The relationship between false confessions and ADHD inattention and hyperactivity/impulsivity symptoms was investigated in two ways. Firstly, by comparing the mean childhood scores, measured by the WURS, and adult (measured by the DSM-IV-TR) ADHD scores, between the false confessors and the other prisoners by the use of t-tests and effect size using Cohen’s d (i.e., the ADHD measures were used as dimensions). Secondly, by a logistic regression analysis, where the dependent measure was false confessors versus non-false confessors, and the independent measures (ADP, hyperactivity/impulsivity, and inattention), used as categorical scores, were entered in three steps in order to study their individual effects. The three predictors were binary variables, where the hyperactivity/impulsivity and inattention measures were categorised into those participants who were either symptomatic or not symptomatic for: (a) hyperactivity/ impulsivity; and (b) inattention, defined as those who scored more than one standard deviation above the mean on each of the two scales.
Table 2 The relationship between a history of false confession, Antisocial Personality Disorder (APD), and being symptomatic for hyperactivity/impulsivity and inattention (categorical classification of all variables). APD Yes False confessors
No
18/52 (34.6%) 4/38 (10.5%) X2 = 6.90, p < 0.01 OR = 1.64, CI = 1.20–2.23
ADHD-hyperactivity/impulsivity
ADHD-inattention
Yes
No
Yes
6/18 (33.3%) X2 = 0.90, n.s.
16/71 (22.5%)
10/19 (52.6%) 12/70 (17.1%) X2 = 10.11, p < 0.001 OR = 3.38, CI = 1.58–7.24
No
Table 3 Summary of the logistic (binary) regression for Antisocial Personality Disorder (APD), ADHD hyperactivity/impulsivity and inattention in predicting false confession. Explanatory variables
Exp(B)
CI (95%)
Block 1 APD 1.47 (0.60) 5.95* Block 1 statistics: R2 = 0.11 (Nagelkerke). Block v2 = 7.11**. Model v2 = 7.11**. Overall classification 75.3%
B (S.E.)
Wald
4.37
1.34–14.28
Block 2 APD 1.43 (0.61) 5.48* Hyperactivity/impulsivity 0.27 (0.60) 0.20 Block 2 statistics: R2 = 0.12 (Nagelkerke). Block v2 = 0.19. Model v2 = 7.30*. Overall classification 75.3%
4.19 1.30
1.26–13.90 0.40–4.22
Block 3 APD 1.03 (0.65) 2.51 2.81 Hyperactivity/impulsivity 0.50 (0.74) 0.46 0.61 4.64 ADHD-inattention 1.53 (0.71) 4.66* Block 3 statistics: R2 = 0.19 (Nagelkerke). Block v2 = 5.02*. Model v2 = 12.32**. Overall classification 82.0%, 31.8% for false confessors and * **
p < 0.05. p < 0.01.
0.78–10.05 0.14–2.60 1.15–18.67 98.5% for controls
G.H. Gudjonsson et al. / Personality and Individual Differences 48 (2010) 720–724
Both methods produced the same results; false confessions were more strongly associated with inattention than hyperactivity/impulsivity. Indeed, the binary logistic regression showed that after entering APD, hyperactivity/impulsivity was not a significant predictor of false confession, and after inattention was entered in the third step, inattention remained the single best predictor after controlling for APD and hyperactivity/impulsivity. The final model correctly classified 98.5% of the non-false confessors and 31.8% of the false confessors with an overall classification of 82.0%, which is almost identical to the classification of false confessors found by Sigurdsson and Gudjonsson (2001) using a large range of psychological and criminological measures. The data from both studies suggest an extremely high level of specificity (i.e., correct identification non-false confessors), but only a modest level of sensitivity (i.e., identification of false confessors). The finding that a diagnosis of APD significantly predicted a preexisting history of false confession is consistent with the literature (Gudjonsson, 2003; Sigurdsson & Gudjonsson, 1996; Sigurdsson & Gudjonsson, 2001). Gudjonsson, Sigurdsson, Bragason, Einarsson, and Valdimarsdottir (2004) found among a large sample of college students that antisocial personality traits, measured by the Gough Socialisation Scale (Gough, 1960) and the Psychoticism dimension of the Eysenck Personality Questionnaire (EPQ; Eysenck & Eysenck, 1975), were associated with false confessions. The authors suggested that the reason was that persons with personality disorder traits lie to police during questioning for instrumental gains and have disregard for the consequences of their deception. Another possibility is that people with antisocial personality traits are more involved in crime and get arrested and questioned more often by police, which leaves them susceptible to making a false confession (Gudjonsson, Sigurdsson, Asgeirsdottir, & Sigfusdottir, 2006; Gudjonsson, Sigurdsson, & Sigfusdottir, 2009; Gudjonsson, Sigurdsson, Sigfusdottir, & Asgeirsdottir, 2008b). It may be that conduct disorder and ADHD increase the likelihood that they get involved with offending and police questioning (Barkley et al., 2004). The present findings provide a new insight into the nature of false confessions. APD and ADHD are significantly associated with false confession, but the present findings demonstrate that it is specifically the inattention component of ADHD which is the single best predictor of false confessions. It is even more powerful than APD. This is a surprising finding and requires an explanation. What is it that mediates the relationship between inattention and false confession? The key is likely to be the anxiety and disorganisational aspect of ADHD. Gudjonsson, Sigurdsson, Gudmundsdottir, Sigurjonsdottir, and Smari (in press) have shown that the core component of maladaptive personality associated with the ADHD inattention symptoms is impaired capacity to set and achieve realistic goals. Maedgen and Carlson (2000) found that children with ADHD had impaired social functioning in comparison with controls, but important differences existed between ADHD subgroups. The ADHD combined type was significantly impaired both in terms of social performance and emotional regulation, whereas the predominantly inattentive type only displayed deficits in social knowledge and social passivity. It may be the social passivity part of the inattentive ADHD type, which appears a similar construct to that measured in adults by the Gudjonsson Compliance Scale (GCS; Gudjonsson, 1989, 1997) and their disorganization in day to day living, interfere with their ability to cope with police questioning and detention and makes it difficult for them to resist the temptation to take the blame for a peer (Gudjonsson, Sigurdsson, & Einarsson, 2007). In future studies, it would be important to measure social passivity and compliance and investigate to what extent they may mediate the relationship between inattention and false confessions. It would be expected from the findings in the present study that compliance would be better correlated with inattention
723
than hyperactivity/impulsivity. Persons diagnosed with ADHD have not been found to be unduly suggestible during questioning, but their general vagueness and disorganisation when questioned may leave them impaired in coping with police questioning (Gudjonsson, Young, & Bramham, 2007). The current findings have important implications for habitual offenders, some of whom undoubtedly have ADHD when interviewed by police (Sigurdsson, Gudjonsson, Einarsson, & Gudjonsson, 2006). In the present study, false confessions were only found to be related to ADHD symptoms in adulthood (i.e., during the previous six months at the time of the study). The mean scores on the WURS did not differentiate between the false confessors and other prisoners. This could be due to either the limitations of the instruments (i.e., there is no differentiation between the hyperactivity/impulsivity and inattention symptoms) or that the current (adult) symptoms rather than the childhood symptoms are only relevant to false confessions. One possibility is that childhood ADHD symptoms, particularly when accompanied by conduct disorder and substance use, lead to delinquency and adult offending (Gudjonsson, Young, & Wells, under review), but it is the residual inattention that leaves them additionally vulnerable to giving a false confession to the police during questioning. The main limitation of the present study is the small number of cases of false confessions, which impacts on power. This is perhaps most evident in the logistic regression with regard to APD and hyperactivity/impulsivity categorisation. The second limitation is that the reporting of false confessions could not be independently corroborated. Those participants who claimed to have made a false confession were asked specific follow-up questions about the false confession and this also ensured that they had properly understood the question regarding false confessions. Thirdly, the ADHD symptoms were based on self-reported DSM screens, but these have been found to be highly correlated with those found in a diagnostic interview (Magnusson et al., 2006; Murphy & Schachar, 2000). Fourthly, only male participants were included in the study. The study of Sigurdsson and Gudjonsson (1996) conducted among a similar group of prisoners in the mid-1990s found that 15% of the false confessors were female. They differed from the male false confessors in terms of the motivation for making the false confession (i.e., all of them had allegedly made a false confession to protect somebody else, in contrast to only about half of the male false confessors). The rate of ADHD among female prisoners is very high (Rosler, Retz, Yaqoobi, Burg, & Retz-Junginer, 2009), which means that future research into the relationship between ADHD symptoms and false confessors should whenever possible focus on both males and females. In spite of the limitations of the present study, the findings are clear. Inattention is a more powerful predictor of false confession than hyperactivity/impulsivity and APD. Future studies into ADHD and false confessions should separate the inattention and hyperactivity/impulsivity items and investigate the specific mechanisms involved. Acknowledgement The authors would like to thank Maria Hronn Nikulasdottir for computing the data and the Nordic Council of Criminology for funding the study. References American Psychiatric Association (2000). Diagnostic and statistical manual of mental disorders (DSM-IV-TR). Washington, DC: American Psychiatric Association. Barkley, R. A., Fischer, M., Smallish, L., & Fletcher, K. (2004). Young adult follow-up of hyperactive children: Antisocial activities and drug use. Journal of Child Psychology and Psychiatry, 45, 195–211.
724
G.H. Gudjonsson et al. / Personality and Individual Differences 48 (2010) 720–724
Cohen, J. (1988). Statistical power analysis for the behavioural sciences. Hillsdale, NJ: Erlbaum. Drizin, S. A., & Leo, R. A. (2004). The problem of false confessions in the post-DNA world. North Carolina Law Review, 82, 891–1007. Einarsson, E., Sigurdsson, J. F., Gudjonsson, G. H., Newton, A. K., & Bragason, O. O. (2009). Screening for attention deficit hyperactivity disorder and co-morbid mental disorders among prison inmates. Nordic Journal of Psychiatry, 63, 361–367. Eysenck, H. J., & Eysenck, S. B. G. (1975). Manual of the Eysenck personality questionnaire. London: Hodder and Stoughton. Field, A. (2003). Discovering statistics using SPSS. London: Sage. Gough, H. H. (1960). Theory and measurement of socialization. Journal of Consulting and Clinical Psychology, 24, 23–30. Gudjonsson, G. H. (1989). Compliance in an interrogation situation: A new scale. Personality and Individual Differences, 10, 535–540. Gudjonsson, G. H. (1997). The Gudjonsson suggestibility scales manual. Hove: Psychology Press. Gudjonsson, G. H. (2003). The psychology of interrogations and confessions: A handbook. John Wiley: Chichester. Gudjonsson, G. H. (in press). The psychology of false confessions: A review of the current evidence. In G. Daniel Lassiter & Christian A. Meissner (Eds.), Interrogations and confessions: Research, practice, and policy. New York: American Psychological Association. Gudjonsson, G. H. (2006). Disputed confessions and miscarriages of justice in Britain: Expert psychological and psychiatric evidence in court of appeal. The Manitoba Law Journal, 31, 489–521. Gudjonsson, G. H., & Sigurdsson, J. F. (1994). How frequently do false confessions occur? An empirical study among prison inmates. Psychology, Crime and Law, 1, 21–26. Gudjonsson, G. H., Sigurdsson, J. F., Asgeirsdottir, B. B., & Sigfusdottir, I. D. (2006). Custodial interrogation, false confession and individual differences. A national study among Icelandic youth. Personality and Individual Differences, 41, 49–59. Gudjonsson, G. H., Sigurdsson, J. F., Bragason, O. O., Einarsson, E., & Valdimarsdottir, E. B. (2004). Confessions and Denials and the relationship with personality. Legal and Criminological Psychology, 9, 121–133. Gudjonsson, G. H., Sigurdsson, J. F., & Einarsson, E. (2007). Taking blame for antisocial acts and its relationship with personality. Personality and Individual Differences, 43, 3–13. Gudjonsson, G. H., Sigurdsson, J. F., Einarsson, E., Bragason, O. O., & Newton, A. K. (2008a). Interrogative suggestibility, compliance and false confessions among prisoners and their relationship with attention deficit hyperactivity disorder (ADHD) symptoms. Psychological Medicine, 38, 1037–1044. Gudjonsson, G. H., Sigurdsson, J. F., Gudmundsdottir, H. B., Sigurjonsdottir, S., & Smari, J. (in press). The relationship between ADHD symptoms in college students and core components of maladaptive personality. Personality and Individual Differences. doi:10.1016/j.paid.2009.12.015. Gudjonsson, G. H., Sigurdsson, J. F., & Sigfusdottir, I. D. (2009). Interrogations and false confessions among adolescents in seven countries in Europe. What background and psychological factors best discriminate between false confessors and non-false confessors? Psychology, Crime and Law, 15, 711–728. Gudjonsson, G. H., Sigurdsson, J. F., Sigfusdottir, I. D., & Asgeirsdottir, B. B. (2008b). False confessions and individual differences. The importance of victimization among youth. Personality and Individual Differences, 45, 801–805. Gudjonsson, G. H., & Young, S. (2006). An overlooked vulnerability in a defendant: Attention deficit hyperactivity disorder and a miscarriage of justice. Legal and Criminological Psychology, 11, 211–218. Gudjonsson, G. H., Young, S., & Bramham, J. (2007). Interrogative suggestibility in adults diagnosed with attention-deficit hyperactivity disorder (ADHD). A potential vulnerability during police questioning. Personality and Individual Differences, 43, 737–745.
Gudjonsson, G. H., Young, S., & Wells, J. (under review). The role of Attention Deficit Hyperactivity Disorder (ADHD) and substance use in the offending history of prisoners. Kassin, S. M., & Gudjonsson, G. H. (2004). The psychology of confessions. A review of the literature and issues. Psychological Science in the Public Interest, 5, 33–67. Maedgen, J. W., & Carlson, C. L. (2000). Social functioning and emotional regulation in the attention deficit hyperactivity disorder subtypes. Journal of Clinical Child Psychology, 29, 30–42. Magnusson, P., Smari, J., Sigurdardottir, D., Baldursson, G., Sigmundsson, J., Kristjansson, K., et al. (2006). Validity of self-report and informant rating scales of adult ADHD symptoms in comparison with a semistructured diagnostic interview. Journal of Attention Disorders, 9, 494–503. Murphy, P., & Schachar, R. (2000). Use of self-ratings in the assessment of symptoms of Attention Deficit Hyperactivity Disorder in adults. American Journal of Psychiatry, 157, 1156–1159. Pinninti, N. R., Madison, H., Musser, E., & Rissmiller, D. (2003). MINI International Neuropsychiatric Schedule: Clinical utility and patient acceptance. European Psychiatry, 18, 361–364. Rasmussen, K., Almvik, M. R., & Levander, S. (2001). Attention deficit hyperactivity disorder, reading disability, and personality disorders in a prison population. The Journal of the American Academy of Psychiatry and the Law, 29, 186–193. Rosler, M., Retz, W., Yaqoobi, K., Burg, E., & Retz-Junginer, P. (2009). Attention deficit/hyperactivity disorder in female offenders: Prevalence, psychiatric comorbidity and psychosocial implications. European Archives of Psychiatry in Clinical Neuroscience, 259, 98–105. Sheehan, D. V., Lecrubier, Y., Sheehan, K. H., Amorin, P., Janavs, J., Weiller, E., et al. (1998). The Mini-International Neuropsychiatric Interview (M.I.N.I.): The development and validation of a structured diagnostic psychiatric interview for DSM-IV and ICD-10. Journal of Clinical Psychiatry, 59, 22–33. Sheehan, D. V., Lecrubier, Y., Sheehan, K. H., Janavs, J., Weiller, E., Keskiner, A., et al. (1997). The validity of the Mini International Neuropsychiatric Interview (MINI) according to the SCID-P and its reliability. European Psychiatry, 12, 232–241. Sigurdsson, J. F., & Gudjonsson, G. H. (1996). Psychological characteristics of ‘false confessors’. A study among Icelandic prison inmates and juvenile offenders. Personality and Individual Differences, 20, 321–329. Sigurdsson, J. F., & Gudjonsson, G. H. (2001). False confessions: The relative importance of psychological, criminological and substance abuse variables. Psychology, Crime and Law, 7, 275–289. Sigurdsson, J. F., Gudjonsson, G. H., Einarsson, E., & Gudjonsson, G. (2006). Differences in personality and mental state between suspects and witnesses immediately after being interviewed by the police. Psychology, Crime and Law, 12, 619–628. Ward, M. F., Wender, P. H., & Reimherr, M. D. (1993). The Wender Utah Rating Scale: An aid in the retrospective diagnosis of childhood Attention Deficit Hyperactivity Disorder. American Journal of Psychiatry, 150, 885–890. Young, S. (2004). The YAQ-S AND YAQ-I: The development of self and informant questionnaires reporting on current adult ADHD symptomatology, comorbid and associated problems. Personality and Individual Differences, 36, 1211–1224. Young, S. (2007). Forensic aspects of ADHD. In Ml. Fitzarald, M. Bellgrove, & M. Gill (Eds.), Handbook of attention deficit hyperactivity disorder (pp. 91–108). Chichester: John Wiley & Sons. Young, S., & Gudjonsson, G. (2006). ADHD symptomatology and its relationship with emotional, social and delinquency problems. Psychology, Crime and Law, 12, 463–471. Young, S., & Gudjonsson, G. H. (2008). Growing out of ADHD: The relationship between functioning and symptoms. Journal of Attention Disorder, 12, 162–169. Young, S., Gudjonsson, G. H., Wells, J., Asherson, P., Theobald, D., Oliver, B., et al. (2009). Attention Deficit Hyperactivity Disorder and critical incidents in a Scottish prison population. Personality and Individual Difference, 46, 265–269.