The Minnesota Multiphasic Personality Inventory is invalid as forensic lie detector, courts rule

The original Wall Street Journal article on all this can be seen via the WSJ Blog here (here's a snippet)

Today, a WSJ front-pager looks at a psychology test, used increasingly by defendants in personal injury lawsuits, called the Fake Bad Scale. In hundreds of cases, says the story, expert witnesses have testified that the test provided evidence that plaintiffs were lying about their injuries. The test gained credibility recently after being endorsed by the Minnesota Multiphasic Personality Inventory.

But now psychologists and plaintiffs’ lawyers claim that the Fake Bad Scale identifies too many real victims as fakers, known as malingerers, people who exaggerate their symptons to win judgments in court. “Virtually everyone is a malingerer according to this scale,” says a leading critic, James Butcher, a retired University of Minnesota psychologist who has published research faulting the Fake Bad Scale. “This is great for insurance companies, but not great for people.”

We now have an extended article on this mess. As found and reposted from Karen Franklin's Forensic Psychology Blog, linked from the Sentencing Law & Policy blog, with a tip of the hat to one of our readers

Psychology's most widely used personality test, the MMPI, jumped into the national spotlight today in a fascinating David-and-Goliath controversy pitting corporate interests such as Halliburton against the proverbial little guy.

At issue is the "Fake Bad" scale that was incorporated into the Minnesota Multiphasic Personality Inventory last year for use in personal injury litigation. A front-page critique in today's Wall Street Journal includes publication of the items on the contested scale, a test security breach that will no doubt have the publisher seeing red.

Although a majority of forensic neuropsychologists said in a recent survey that they use the scale, critics say it brands too many people - especially women - as liars. Research finding an unacceptably large false-positive rate includes a large-scale study by MMPI expert James Butcher, who found that the scale classified high percentages of bonafide psychiatric inpatients as fakers.

One possible reason for this is that the scale includes many items that people with true pain or trauma-induced disorders might endorse, such as "My sleep is fitful and disturbed" and "I have nightmares every few nights." Yet hearing the term "Fake Bad" will likely make a prejudicial impact on jurors even if they hear from opposing experts who say a plaintiff is not faking.

The controversy came to a head last year in two Florida courtrooms, where judges barred use of the scale after special hearings on its scientific validity. In a case being brought against a petroleum company, a judge ruled that there was "no hard medical science to support the use of this scale to predict truthfulness.” Other recent cases in which the scale has been contested include one against Halliburton brought by a former truck driver in Iraq.

The 43-item scale was developed by psychologist Paul Lees-Haley, who works mainly for defendants in personal injury cases and charges $600 an hour for his depositions and court appearances, according to the Journal article. In 1991, he paid to have an article supportive of the scale published in Psychological Reports, which the WSJ describes as "a small Montana-based medical journal."

The scale was not officially incorporated into the MMPI until last year, after a panel of experts convened by the University of Minnesota Press reported that it was supported by a "preponderance of the current literature." Critics maintain that the review process was biased: At least 10 of the 19 studies considered were done by Lees-Haley or other insurance defense psychologists, while 21 other studies – including Butcher's – were allegedly excluded from consideration.

Later last year, the American Psychological Association's committee on disabilities protested to the publisher that the scale had been added to the MMPI prematurely.

Lees-Haley, meanwhile, defends the scale as empirically validated and says criticism is being orchestrated by plaintiff's attorneys such as Dorothy Clay Sims, who has written guides on how to challenge the Fake Bad scale in court.

Even if the scale was valid before today, questions are certain to arise about the extent to which it will remain valid once litigants start studying for it by using today's publication of all 43 items along with the scoring key.

The lesson for forensic practitioners: Be aware of critical literature and controversy surrounding any test that you use in a forensic context, and be prepared to defend your use of the test in court.

The article, "Malingerer Test Roils Personal-Injury Law; 'Fake Bad Scale' Bars Real Victims, Its Critics Contend," which includes ample details on the controversy, is only available to Wall Street Journal subscribers, but you can try retrieving it with a Google news search using the term "MMPI Fake Bad." The University of Minnesota Press webpage on the contested scale is here, along with a list of research citations.

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Here are citations to the major pro and con research articles:

"Meta-analysis of the MMPI-2 Fake Bad Scale: Utility in forensic practice," Nelson, Nathaniel W., Sweet, Jerry J., & Demakis, George J., Clinical Neuropsychologist, Vol 20(1), Feb 2006, pp. 39-58 (pdf available here)

"The construct validity of the Lees-Haley Fake Bad Scale: Does this measure somatic malingering and feigned emotional distress?: Butcher, James N., Arbisi, Paul A., & Atlis, Mera M., Archives of Clinical Neuropsychology, Vol 18(5), Jul 2003, pp. 473-485. (pdf available here)

The original source of the scale is known, see this item:

Dr. Paul Lees-Haley, a psychologist, who makes his living primarily helping insurance companes in personal injury cases has designed a "Fake Bad Scale" psychological test to challenge personal injury claimants. An article in the March 5, 2008 Wall Street Journal describes how Dr. Lees-Haley developed the test and convinced the Minnesota Multiphasic Personality Inventory, MMPI, to make the Fake Bad Scale an official subset of the MMPI. This Fake Bad Scale has been used by the KBR unit of Halliburton Inc. to deny disability claims of truck drivers who worked in Iraq by labeling them as malingerers.

However, the court in two Tampa, Florida auto personal injury cases has rightly excluded the Fake Bad Scale from the courtroom. The scientific basis of this test has not been properly demonstrated. Furthermore, it has long been the jury's job to evaluate the credibility of courtroom witnesses.

Using a psychological test such as the Fake Bad Scale as evidence in a trial invades the proper province and job of the jury to make that evaluation. The use of a lie detector test is not admissible in court for the same reasons.

In essence, Dr. Lees-Haley and the auto insurance companies are attempting to use this Fake Bad Scale as a lie detector test. Our jury system does and should provide justice though jury trials on all the issues, not through a machine or a test designed by an insurance company consultant.