Biased Symptom Reporting and Antisocial Behaviour in Forensic Samples: A Weak Link

Figures & data

Table 1. Summary of means, SDs, 95% confidence intervals and prevalence rates of diagnoses and cut-off failures in the forensic patient sample (n = 57).

	M (SD)	95% CI	Percentage exceeding cut-off	Percentage of most frequent diagnoses of patients scoring > cut-off
SIMS	8.6 (6.6)	[6.8, 10.3]	9% (5 out of 57) >16	60% IQ <75, 40% OSPD
SS	16.4 (6.5)	[14.7, 18.2]	23% (13 out of 57) >21	38% OSPD, 23% IQ <75
LSRPS	52.6 (9.6)	[48.6, 56.6]	28% (7 out of 25) >57	No diagnoses with a count > 1
SDAS-11	17.1 (12.5)	[13.8, 20.4]	16% (8 out of 57) >1.5 SDs	38% IQ <75, 25% OSPD

Note: LSRPS = Levenson Self-Report Psychopathy scale; OSPD = other specified personality disorder; SDAS-11 = Social Dysfunction and Aggression Scale-11; SIMS = Structured Inventory of Malingered Symptomatology; SS = Supernormality Scale.

Table 2. Pearson product–moment correlations and 95% confidence intervals for the Study 1 data.

Measure	1 SIMS	2 SS	3 LSRPS
2 SS	−.28* [−.50, −.02]	–
3 LSRPSᵃ	.31 [−.09, .63]	−.10 [−.30, .48]	–
4 SDAS-11	−.04 [−.30, .22]	.00 [−.26, .26]	.27 [−14, .60]

Note: *p < .05, two-tailed; ᵃn = 25. LSRPS = Levenson Self-Report Psychopathy Scale; SDAS-11 = Social Dysfunction and Aggression Scale-11; SIMS = Structured Inventory of Malingered Symptomatology; SS = Supernormality Scale.

Table 3. Numbers of forensic patients (n = 57) with increasing, constant, or decreasing antisocial behaviour who over-report or under-report symptoms.

	Over-reporting (SIMS)		Under-reporting (SS)
SDAS-11	Below cut-off (≤16)	Above cut-off (>16)	Below cut-off (≤21)	Above cut-off (>21)
Increasing	21 (37%)	2 (4%)	18 (32%)	5 (9%)
Stable	24 (42%)	2 (4%)	20 (35%)	6 (11%)
Decreasing	7 (12%)	1 (2%)	6 (11%)	2 (4%)

Note: SDAS-11 = Social Dysfunction and Aggression Scale-11; SIMS = Structured Inventory of Malingered Symptomatology; SS = Supernormality Scale.

Table 4. Summary of means, SDs, 95% confidence intervals and prevalence rates of cut-off failures in the forensic punitive sample (n = 45).

	M (SD)	95% CI	Percentage exceeding cut-off
SIMS	10.6 (5.2)	[9.1, 12.2]	13% (6 out of 45) >16
SDS-5	16.7 (2.7)	[15.9, 17.5]	N/A
LSRPS	58.9 (9.3)	[56.1, 61.7]	56% (25 out of 45) >57
BAI External	29.5 (8.5)	[26.9, 32.0]	N/A
BAI Mental	25.0 (6.6)	[23.0, 27.0]	N/A
BAI Guilt	54.6 (11.7)	[51.1, 58.2]	N/A
Prison term (years)	2.5 (1.4)	[2.1, 2.9]	N/A
Punitive actions	0.5 (0.9)	[0.3, 0.8]	N/A
Intensive offender	N/A	N/A	22% (10 out of 45)

Note: BAI = Revised Gudjonsson Blame Attribution Inventory; LSRPS = Levenson Self-Report Psychopathy Scale; Punitive actions = relative number of punitive actions taken against participants; SDS-5 = Social Desirability Scale-5; SIMS = Structured Inventory of Malingered Symptomatology.

Table 5 Pearson product–moment correlations and 95% confidence intervals for the Study 2 data.

		1 SIMS	2 SDS-5	3 LSRPS	4 BAI External	5 BAI Mental	6 BAI Guilt	7 Prison term (years)	8 Punitive actions
2	SDS-5	−.42** [−.63, −.14]	–
3	LSRPS	.60** [.37, .76]	−.50** [−.69, −.24]	–
4	BAI External	.35* [.06, .59]	−.27 [−.53, .03]	.41** [.13, .63]	–
5	BAI Mental	.43** [.16, .65]	−.12 [−.40, .18]	.24 [−.06, .50]	.18 [−.12, .46]	–
6	BAI Guilt	−.09 [−.38, .21]	.21 [−.10, .47]	−.26 [−.52, .04]	−.50** [−.70, −.24]	.33* [.04, .57]	–
7	Prison term (years)	.23 [−.08, .49]	−.17 [−.45, .13]	.09 [−.21, .38]	−.11 [−.39, .19]	.22 [−.09, .48]	−.01 [−.31, .29]	–
8	Punitive actions	−.05 [−.34, .25]	.16 [−.15, .43]	.01 [−.28, .30]	−.05 [−.34, .25]	−.01 [−.30, .28]	.08 [−.22, .36]	.13 [−.17, .41]	–
9	Intensive offender	−.14 [−.42, .16]	.02 [−.28, .31]	.02 [−.28, .31]	−.02 [−.31, .28]	−.03 [−.32, .27]	.04 [−.26, .33]	.33* [−.04, .57]	−.02 [−.31, .28]

Note: *p < .05, two-tailed; **p < .01, two-tailed. BAI = Revised Gudjonsson Blame Attribution Inventory; LSRPS = Levenson Self-Report Psychopathy Scale; Punitive actions = relative number of punitive actions taken against participants; SDS-5 = Social Desirability Scale-5; SIMS = Structured Inventory of Malingered Symptomatology.

Table 6. Prevalence rates and corresponding percentages of incorrect predictions of symptom over-reporting among antisocial patients and antisocial behaviour among over-reporting patients.

Authors	Prevalence of symptom over-reporting among antisocial patients	False positive predictions	Prevalence of antisocial behaviour among over-reporting patients	False negative predictions
Study 1	0% (ASPD) 0% (SDAS-11 >1.5 SDs) 0% (LSRPS >57)	100% 100% 100%	ASPD: 0% SDAS-11 >1.5 SD: 0% LSRPS >57: 0%	100% 100% 100%
Study 2	0% (Intensive offender) 24% (LSRPS >57)	100% 76%	Intensive offenders: 0% LSRPS >57: 100%	100% 0%
Delain et al. (2003)	83% (ASPD)^a	17%	ASPD: 17%	83%
Gacono et al. (1995)^b	64% (ASPD)^a 90% (Psychopathy)^a	36% 10%	ASPD: 100% Psychopathy: 100%	0% 0%
Heinze and Vess (2005)	11% (Psychopathy)	89%	Psychopathy: 33%^a	67%
Kucharski, Duncan et al. (2006)	33% (Psychopathy)	67%	Psychopathy: 52%^a	48%
Kucharski, Falkenbach et al. (2006)	31% (ASPD)	69%	ASPD: 72%^a	28%

Note: ^aCalculated using available information; ^bEmployed two samples: malingerers and non-malingerers. ASPD = antisocial personality disorder; LSRPS = Levenson Self-Report Psychopathy Scale; SDAS-11 = Social Dysfunction and Aggression Scale-11. Studies gathered from Niesten et al. (2015), and via a thorough search via Google Scholar using the search terms ‘psychopathy’ and ‘antisocial personality disorder’ combined with ‘malingering’, ‘feigning’, ‘simulation’, and ‘dissimulation’. Aside from the present studies, only studies that found a statistically significant relationship between symptom over-reporting and antisocial behaviour are included.

Delain, S. L., Stafford, K. P., & Ben-Porath, Y. S. (2003). Use of the TOMM in a criminal court forensic assessment setting. Assessment, 10, 370–381.

 PubMed Web of Science ®Google Scholar

Gacono, C. B., Meloy, J. R., Sheppard, K., Speth, E., & Roske, A. (1995). A clinical investigation of malingering and psychopathy in hospitalized insanity acquitees. Bulletin of the American Academy of Psychiatry and the Law, 23, 387–397.

 PubMedGoogle Scholar

Heinze, M. C., & Vess, J. (2005). The relationship among malingering, psychopathy, and the MMPI-2 validity scales in maximum security forensic psychiatric inpatients. Journal of Forensic Psychology Practice, 5, 35–53.

 Web of Science ®Google Scholar

Kucharski, L. T., Duncan, S., Egan, S. S., & Falkenbach, D. M. (2006). Psychopathy and malingering of psychiatric disorder in criminal defendants. Behavioural Sciences and the Law, 24, 633–644.

 PubMed Web of Science ®Google Scholar

Niesten, I. J. M., Nentjes, L., Merckelbach, H., & Bernstein, D. P. (2015). Antisocial features and “faking bad”: A critical note. International Journal of Law and Psychiatry, 41, 34–42.

 PubMed Web of Science ®Google Scholar