We tested whether the judgment of forensic psychiatric experts differed from that of laypersons. We constructed 18 case vignettes that were rated by 21 psychologists, 14 psychiatrists, and 126 laypeople on the following variables: Insanity by Legal Terms, Risk of Repeated Offense, and Need of Treatment. We found significant differences among laypeople and professionals on all three variables (p = .008, p = .024, and p = .009, respectively), although the differences were dependent on the composition of the case vignettes. Case vignettes containing negative descriptions and/or serious crimes were rated high on all variables by laypeople, whereas the professional groups? ratings varied according to the variations given in the information.
Get full access to this article
View all access options for this article.
References
1.
AckersonK.S.BrodskyS.L.2005. Judges' and psychologists' assessments of legal and clinical factors in competence for execution. Psychology, Public Policy, and Law, 11: 164–193.
2.
AllanA.LouwD.A.VerschoorT.1995. Expert evidence: the emergence of psychiatry and psychology (2). Med Law, 14: 677–684.
3.
BjørklyS.1998. Interrater reliability of the report form for aggressive episodes in group ratings. Perseptual and Motor Skills, 87: 1405–1406.
4.
CimaM.MerckelbachH.NijmanH.KnauerE.HollnackS.2002. I can't remember your honour: offenders who claim amnesia. German Journal of Psychiatry, 5: 24–34.
5.
ColesE.M.VeielH.O. F.2001. Expert testimony and pseudoscience: How mental health professionals are taking over the courtroom. International Journal of Law and Psychiatry, 24: 607–625.
6.
DawesR.M.1994. House of cards, , 1st ed., New York: The Free Press.
7.
EbbesenE.B.KonecniV.J.1975. Decision making and information integration in the courts: the setting of bail. Journal of Personality and Social Psychology, 32: 805–821.
8.
EinhornH.J.1974. Expert judgement: some necessary conditions and an example. Journal of Applied Psychology, 59: 562–571.
9.
EnnisB.LitwakT.1974. Psychiatry and the presumption of expertise: Flipping coins in the courtroom. California Law Review, 62: 693–752.
10.
FaustD.ZiskinJ.1988. The expert witness in psychology and psychiatry. Science, 241: 31–35.
11.
FoucaultM.1978. About the concept of the “dangerous individual” in 19th - century legal psychiatry. International Journal of Law and Psychiatry, 1: 1–18.
12.
GrøndahlP.2005. Scandinavian forensic psychiatric practices—an overview and evaluation. Nordic Journal of Psychiatry, 59: 92–102.
13.
GrøndahlP.IkdahlS.E.DahlA.A.2007. A study of forensic psychiatric screening reports and their relationship to full psychiatric reports. The Journal of Forensic Psychiatry & Psychology, 18: 331–341.
14.
GutheilT.G.SimonR.I.2005. Narcissistic dimensions of expert witness practice. Journal of the American Academy of Psychiatry and the Law, 33: 55–58.
15.
HeilbrunK.H.CollinsS.1995. Evaluations of trial competency and mental state at time of offence: report characteristics. Professional Psychology: Research and Practice, 26: 61–67.
16.
HughesH.D.1917. An interesting seed corn experiment. The Iowa Agriculturist, 17: 424–425.
17.
JacksonM.N.1985. Psychiatric decision-making for the courts: Determining the nature of mental health expertise, University of Toronto. Unpublished doctoral thesis
18.
JacksonM.N.1986. Psychiatric decision-making for the courts: Judges, psychiatrists, lay people?. International Journal of Law and Psychiatry, 9: 507–520.
19.
KirkebøenG.1999. Skjønn, formler og klinisk praksis: Hvorfor vurderer erfarne klinikere så dårlig enda de vet så mye?. Tidsskrift for Norsk Psykologforening, 36: 523–536.
20.
McKennaB.ThomK.SimpsonA.I. F.2007. Media coverage of homicide involving mentally disordered offenders: a matched comparison study. International Journal of Forensic Mental Health, 6: 57–63.
21.
NedopilN.2002. The boundaries of courtroom expertise. The Journal of Forensic Psychiatry, 13: 494–498.
22.
OscampS.1965. Overconfidence in case-study judgments. The Journal of Consulting Psychology, 29: 261–265.
23.
PetrellaR.C.PoythressN.G.1983. The quality of forensic evaluations: an interdisciplinary study. Journal of Consulting and Clinical Psychology, 51: 76–85.
24.
R Development Core Team. 2004. R: A language and environment for statistical computinghttp://www.R-project.org[Computer software]. Vienna, Austria
25.
RoweG.WrightG.2001. Differences in expert and lay judgements of risk: myth or reality?. Risk Analysis, 21: 341–356.
26.
SaksM.J.KoehlerJ.J.2005. The coming paradigm shift in forensic identification science. Science, 309: 892–895.
27.
ShanteauJ.1992. “The psychology of experts: An alternative view”. In Expertise and decision support, Edited by: WrightG.BolgerF.11–23. New York: Plenum press.
28.
SoothillK.L.AdserballeH.BernheimJ.DasananjaliT.HardingT.W.ThomazT.1983. Psychiatric reports requested by the courts in six countries. Med Sci Law, 23: 231–241.
29.
StevensH.B.BrodskyS.L.1995. Perceived consequences to the predictor: a variable in the release of psychiatric patients. Psychological Reports, 76: 1371–1378.
30.
TaylorC.A.SorensonS.B.2007. Intervention on behalf of children exposed to intimate partner violence: Assessment of support in a diverse community-based sample. Child Abuse & Neglect, 31: 1155–1168.
31.
WettsteinR.M.2005. Quality and quality improvement in forensic mental health evaluations. Journal of the American Academy of Psychiatry and the Law, 33: 158–175.
32.
YourstoneJ.LindholmT.GrannM.SvensonO.2008. Evidence of gender bias in legal insanity evaluations: A case vignette stydy of clinicians, judges and students. Nord J Psychiatry, 62: 273–278.
