Rogers, R., & Bender, S. D. (2003). Evaluation of
malingering and deception. In A. M. Goldstein (Ed.),
Handbook of psychology: Vol. 11. Forensic psychology
(pp. 109–129). New York: Wiley.
Rogers, R., & Shuman, D. W. (2005). Fundamentals of
forensic practice: Mental health and criminal law.
New York: Springer.MALINGERING PROBABILITYSCALE
The Malingering Probability Scale (MPS) was devel-
oped in the mid-1990s as a self-report instrument to
estimate the probability of malingering, taking
account of base rates in underlying populations. The
instrument was based on three premises: (1) that psy-
chopathology expresses itself in clearly defined syn-
dromes for which certain symptoms, though perhaps
plausibly related, have very low likelihoods of occur-
rence; (2) that patients will vary in the type of symp-
toms they feign depending on the context; and
(3) that the identification of probabilities of any given
individual of malingering should be adjusted accord-
ing to the base rate of malingering in the population
from which he or she was drawn. The MPS was
developed by Leigh Silverton, who also designed and
conducted many studies; analyzed much of the data;
and, in collaboration with Chris Gruber, wrote the
MPS manual.
At the time the MPS was developed, there were no
other instruments of malingering that provided sensi-
tivity or specificity studies or gave probabilities of
malingering predicated on estimates of base rates in
the population from which the patient was drawn. The
F scale of the Minnesota Multiphasic Personality
Inventory (MMPI), which was most widely used, did
not distinguish a true-focused response set or random
responding. In constructing the MPS, Silverton also
tried to address a different type of feigned psy-
chopathology than had been traditionally covered.
Past instruments in wide usage had focused on bizarre
and psychotic symptoms. Psychotic symptoms tend to
be feigned in criminal contexts in which punishment
for mentally competent persons judged responsible
for their crimes is more aversive than incarceration in
a mental hospital. The focus of the MPS is broader,
comprising both psychotic symptoms and nonpsy-
chotic symptoms of the type that might be feigned in
civil contexts.Civil litigants should be more apt to feign trauma-
related symptoms such as those associated with post-
traumatic stress disorder, depression, and dissociation.
In civil cases, where money damages are the remedy
for a psychological injury, an experienced attorney
understands that certain disorders are most likely to
stem from trauma and thus yield the highest rewards.
Whether through honest questioning by a personal
injury attorney attempting to explore damages,
through outright coaching, or by self-study of diag-
nostic material, a litigant may obtain an impression, if
not a textbook definition, of the trauma-related syn-
drome that he or she should emulate to maximize
rewards. In such a case, a patient may avoid endorsing
bizarre delusional or hallucinatory symptoms repre-
sented by the F scale of MMPI–2 or the M test but
may endorse posttraumatic stress-like symptoms.
The pseudoclinical items of the MPS cover symp-
toms related to trauma as well as those related to psy-
chotic phenomena as might be feigned in a criminal
context. The symptoms might appear, to the sophisti-
cated faker, to reflect depression, dissociation, post-
traumatic disorder, and schizophrenia. Silverton wrote
items that seemed, based on the literature and her clin-
ical experience, to reflect genuine psychopathology
and those that would appear to reflect genuine psy-
chopathology but did not. One such pair of items for
the depression scale is as follows: “I am rarely awak-
ened by sad dreams” F (pseudoitem) and “I sleep
well” F (actual item). Depressed people tend to have
trouble sleeping and may have sad dreams but are
rarely awakened by them. Items such as these were
derived rationally and then validated to arrive at a
139-item instrument to detect malingering.
A standardization sample of 1,016 adults, aged 17
and above, was selected from four regions of the
United States and tested between 1995 and 1996. The
sample was large, contemporary, and nationally repre-
sentative. Although the sample matched the 1994 U.S.
census data adequately in ethnic distribution, the
actual number of ethnic minority participants was
small, a fact that suggests caution in interpreting
results from minorities. Reading level was measured
at third to fourth grade, which should be adequate for
most populations.
There are reasonably good levels of reliability,
using measures of internal consistency, test-retest reli-
ability, and temporal stability and using samples of
individuals from the general population in which the
malingering base rate is relatively high (prison andMalingering Probability Scale——— 475M-Cutler (Encyc)-45463.qxd 11/18/2007 12:43 PM Page 475