Malingering is the intentional production of false or grossly exaggerated physical or psychological symptoms

Malingering is the intentional production of false or grossly exaggerated physical or psychological symptoms motivated by external incentives such as avoiding military duty, avoiding work, obtaining financial compensation, evading criminal prosecution, or obtaining drugs (American Psychiatric Association, 2000). Estimates of its prevalence vary widely. In the United States, for example, Suchy and Sweet (2000) evaluated performance on the Information/Orientation (IO) subtest of the Wechsler Memory Scale–Revised (WMS–R) and estimated that 24% of benefit-seeking patients were malingering, and Andrikopoulos (2001) concluded that the malingering rate is even higher in this same population. Among Dutch patients involved in litigation after whiplash trauma, 61% were identified as malingering (Schmand et al., 1998). In Germany, 14% of 145 patients with chemosensory dysfunction after trauma or exposure to occupational and environmental toxins were classified as malingerers (Delank, Nieschalk, Schmäl, & Stoll, 1999). These high malingering rates pose serious legal and ethical problems for society. They also pose special problems for experts called upon to evaluate the sensory capacities of individuals claiming sensory and perceptual loss. In this article, we introduce a new method to better discriminate patients with a true sensory loss from malingering patients feigning a loss. We will illustrate this method in the context of chemosensory thresholds, but the described technique can be used with any sensory modality. Broadly speaking, the general strategy for detecting malingering is to use techniques that reveal behavior inconsistent with the claimed loss. In the field of personality assessment and psychological/psychiatric disorders, for example, the use of this strategy for the detection of malingering has a long history (Hall & Poirier, 2000; Rogers, 1997). Indeed, most standard diagnostic tests include groups of items specifically designed to detect persons who are faking psychiatric disorders or who are attempting to hide psychiatric disorders (Nicholson et al., 1997). A claimed sensory loss may be the basis of a personal injury lawsuit or the seeking of disability benefits. In such cases, a detailed history of the complaint can reveal inconsistencies, but these by themselves may not be sufficient to prove malingering in a court of law. This research was supported by NIH Grant PO1 DC00244 to M.R.L. We thank Sandra M. Mitchell for serving as the blind tester and for collecting the data. We are grateful to Naomi P. Friedman, who, as a graduate student at the University of Colorado, introduced us to the statistics of sequences. We also thank Christian Kaernbach for insightful comments that led to substantial improvement of this article. L.O.H. greatly benefited from the kind hospitality and stimulating conversations of Peter van der Helm, Emanuel Leeuwenberg, and Charles de Weert, Nijmegen Institute for Cognition and Information (NICI), University of Nijmegen, during a sabbatical visit in January and February of 2001. Some of the results reported here were first presented in 2002 at the 24th Annual Meeting of the Association for Chemoreception Sciences. Correspondence should be addressed to M. R. Linschoten, UCHSC/Box B-205, 4200 East 9th Avenue, Denver, CO 80262 (e-mail: [email protected]).