Friday, November 20, 2009

Malingering in Atkins MR/ID DP cases: State-of-the art, malinger by proxy, and voodoo psychometrics

A quick reading of a small sample of Atkins MR/ID death penalty court decisions makes it clear that the issue of malingering is often a critical component of expert testimony.

The APA Dictionary of Psychology defines malingering as:
the deliberate feigning of an illness or disability to achieve a particular desired outcome (e.g., financial gain or escaping responsibility, punishment, impresonment, or military duty) (p.551)
I am not an expert on the state-of-the-art of the psychometric integrity of various malingering measures used to purportedly detect defendant malingering.  Clearly in capital punishment cases there is the possibility of a strong motivation to score low on IQ tests or standardized measures of adaptive behavior -- lower scores may make the difference between execution or life in prison without parole. Not being an expert in this area of forensic assessment, I'm going to try provide information from high quality sources re: the state-of-the art of malingering assessment.  Also, when appropriate, I will point out situations of inappropriate (unethical?) malingering assessment methods when they are obvious.  This current post contains a sampling of interesting malingering issues, research, and an example of inappropriate malingering assessment.  Click here for prior posts re: malingering issues, research and references.

What does the research say about malingering assessment in the context of intellectual disability determination?

I've found the scholarly work of Salekin and Doane to be of particular value in providing an evaluation of the research in this area. Below are two recent journal articles by Salekin and Doane.  I believe the abstracts/summaries speak for themselves.

Doane, B., & Salekin, K. L. (2009). Susceptibility of current adaptive behavior measures to feigned deficits. Law and Human Behavior, 33, 329-343.

The current study examined the susceptibility of the Adaptive Behavior Assessment System—2nd edition (ABAS-II; Harrison & Oakland, 2003) and the Scales of Independent Behavior—Revised (S1B-R; Bruininks, Woodcock, Weatherman, & Hill, 1996) to the feigning of adaptive functioning deficits. Using four different instruction sets, the authors evaluated whether the provision of diagnostic information (a form of coaching) improved participants’ ability to simulate adaptive deficits commensurate with a diagnosis of mental retardation. The authors found that the ABAS-II was quite vulnerable to believable manipulation by raters, while the SIB-R was not. In fact, exaggeration on the SIB-R was easily detected regardless of the information provided. Implications regarding the use of these measures in Atkins mental retardation evaluations are discussed.

Salekin, K. L., & Doane, B. (2009). Malingering intellectual disability: The value of available measures and methods. Applied Neuropsychology, 16, 105-113.

Atkins v. Virginia (2002) is a case that has changed the landscape in relation to the assessment of malingering in a legal context. This landmark decision abolished the death penalty for defendants found to have intellectual disability (ID; formally known as mental retardation), but limitations in our assessment techniques lead to questions regarding the veracity of ID claims. In fact, Justice Scalia noted with clarity that concerns exist regarding the ability of individuals to feign ID and to do so successfully. At the time of writing, little empirical research has been completed, but that which exists demonstrates an overall lack of validity for traditional measures of cognitive malingering for use with this population. This manuscript provides an overview of the utility of many of the traditional measures of malingering for use with an ID population and serves as a call for research in this very important area.
In closing, review of the research in the assessment of malingered ID demonstrates that effort tests and indices of cognitive malingering are not working with this population, and that true cases can be misidentified as malingered. Some would say that the inclusion of multiple measures of malingering and the interpretation of all of the data together, rather than tests in isolation, provide control for diagnostic error. But to date, we have no data to suggest that either of these techniques is protective and more importantly, we have no data on how a juror or a judge might be impacted by even the slightest mention of malingering. Though untested, these authors posit that it is very unlikely that a defense expert will succeed in supporting an Atkins claim if there is even a hint that malingering may have occurred.

Another interesting topic is malingering resulting from examiner bias.  I find the concept of "malingering by proxy" very interesting.  Below is a discussion of this phenomenon as described by Schlesinger:

Schlesinger, L. B. (2003).  A case study involving competency to stand trial:  Incompetent defendant, incompetent examiner, or "malingering by proxy" ? Psychology, Public Policy, and Law, 9 (3/4), 381-399.
The most blatant kind of examiner bias, however, is seen mostly in forensic cases: the deliberate, conscious intent to distort or misrepresent findings for partisan purposes. This sort of conduct is a breach of professional ethics (Committee on Ethical Guidelines for Forensic Psychologists, 1991), unlike the involuntary forms of bias resulting from patient attributes.
There is yet another variety of examiner bias that is not an automatic act of impaired judgment arising from patient demographics, nor is it an intentional falsification of results. Here, the forensic psychologist finds in the defendant (nonexistent) signs, symptoms, or disorders that were initially suggested by the referring attorney. External incentives (such as economic gain) are typically absent. The effect, which could be called “malingering by proxy,” derives from the forceful opinions of the legal advocate, which can be quite contagious. My impression is that this form of examiner bias is not an uncommon occurrence in forensic work, where the structure of relationships leaves the clinician particularly vulnerable to such (nonconscious) infection.
The genesis of this form of examiner bias begins when the clinician is first approached about the case. Most forensic referrals come from a lawyer who attempts to recruit the consultant for the defense or the prosecution team. For instance, an attorney might call and say:
  • Hello Dr. Z; I was referred to you by a psychiatrist, Dr. Y. She told me you had worked with her on many cases. Your colleague regards you highly and said you are one of the top forensic psychologists in the area. I’d like to retain your services for help with a client I represent. Dr. Y. saw my client yesterday and thought he was mentally retarded. My law partner and I just came back from the county jail, and he seemed retarded to the both of us. We all think he is incompetent to stand trial. Can I count on you to be part of the defense team? By the way, don’t worry about your fee; my client’s family is very supportive of him, and they’ll be sure to pay you promptly.
After an introduction like this, some consultants may find it difficult to disregard the flattery or to challenge members of a “team” they are about to join. However, if forensic psychologists are not careful at this point, they could succumb to a form of examiner bias that could jeopardize the entire evaluation before they have even met the defendant.

Junk science malingering assessment--from actual cases

In two recent Atkins court decisions in the state of Oklahoma (see Salazar, 2005 and Lambert, 2005), the states prosecution psychologist (Dr. Prosecution Psychologist - Dr. PP) testified re: malingering based, in part, on non-normed, non-standardized malingering measures that Dr. PP had developed himself, and one which he named after his secretary (in an attempt to mask the purpose of the test to the defendant).  The two "instruments" in question were the non-standardized Blackwell Memory Test and the Oklahoma Spelling Test.  Apparently the Blackwell Memory test was modelsx after other formal instruments that use a "forced choice symptom validity" test format.   Similar to prior voodoo psychometric activities commented on at this blog, I'm dumb founded that a professional psychologist testifying in an Atkins hearing, or any other clinical or forensic setting, would attempt to assess a psychological construct (viz., malingering) via the development of their own special instrument that did not undergo the professional accepted and required test development procedures (as clearly spelled out the the Joint Test Standards).  This activity clearly violates a number of professional standards. Below are at least two (and I'm sure there are more when one examines all relevant professional codes of ethics/standards) from the Joint Test Standards:
Standard 1.4:  If a test is used in a way that has not been validated, it is incumbent on the user to justify the new use, collecting new evidence if necessary

Standard 11.2.  When a test is to be used for a purpose for which little or no documentation is available, the user is responsible for obtaining evidence of the test's validity and reliability for this purpose

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