Malingering in Forensic Psychology: Feigned Symptoms and Assessment Limits
Author: Ukrainian Psychological Hub · Published: October 11, 2026 · Editorial Policy
Ukrainian Psychological Hub | October 11, 2026
Malingering in forensic psychology refers to the intentional fabrication or substantial exaggeration of symptoms or impairments in pursuit of an external incentive. In a legal evaluation, that question may affect how an examiner interprets psychiatric symptoms, cognitive complaints, reported disability, or an individual's ability to participate in proceedings. The central forensic task is to evaluate the quality and consistency of the evidence before making any inference about deliberate deception or motive.
A person's report may be difficult to verify for many reasons. Genuine psychiatric disorders can produce unusual experiences; trauma, fatigue, medication, pain, linguistic differences, cognitive limitations, and fear can affect performance and disclosure. The presence of litigation, a criminal charge, or a potentially favorable legal outcome creates a reason to examine response validity carefully, but the legal setting itself does not establish malingering. The American Psychological Association's Specialty Guidelines for Forensic Psychology require methods suitable for the referral question and an interpretation attentive to population validity, disability, language, and situational influences.
This article explains what malingering means in forensic psychology, which forms of evidence are used, what symptom and performance validity tests can establish, why false positives matter, and how a responsible forensic opinion differs from a clinical diagnosis or a judicial finding.
What Is Malingering in Forensic Psychology?
The traditional formulation of malingering involves three propositions: symptoms are invented or materially exaggerated; the misrepresentation is intentional; and it serves an external incentive such as financial compensation, relief from duties, access to a desired resource, or avoidance of an adverse outcome. An incentive establishes the context in which feigning is plausible. It does not, by itself, prove either intentional fabrication or the absence of genuine illness.
In current DSM-5-TR terminology, malingering is listed among conditions that may be a focus of clinical attention, rather than classified as a mental disorder. The concept is thus different from diagnoses such as schizophrenia, major depressive disorder, posttraumatic stress disorder, or neurocognitive disorder. Those diagnoses describe clinical conditions. Malingering is an attribution about the intentional presentation of symptoms in a particular context. The AAPL forensic assessment guideline describes the need to examine symptoms, incentives, records, observations, and additional test information together.
The narrower term feigning refers to intentionally producing or presenting false symptoms. Symptom exaggeration refers to claiming greater severity, frequency, or impairment than is supported by the available information. Underperformance refers to test performance that may substantially underestimate capability. An invalid assessment result is a statement about the interpretability of particular evidence. A finding of malingering additionally involves the contested question of intention and external motive. These terms should not be interchanged.
The multidimensional malingering criteria proposed by Sherman, Slick, and Iverson address neurocognitive, somatic, and psychiatric presentations and emphasize convergent findings, substantive discrepancies, alternative explanations, and exclusionary considerations. Those criteria are a research-informed professional proposal, not a universal legal standard or an automatic algorithm for declaring that a person lied.
Why Malingering Matters in Legal Evaluations
Forensic evaluators are often asked questions whose consequences extend beyond diagnosis or treatment. A criminal court may need an opinion on a defendant's present functional abilities to understand proceedings and assist counsel. A criminal responsibility evaluation may examine mental state during an earlier alleged offense. A civil matter may involve psychological injury, impairment, disability, or claimed damages. A correctional assessment may involve current psychiatric needs. Each referral asks a distinct question and calls for evidence matched to that purpose.
A claim that a defendant is feigning severe psychotic symptoms may influence the interpretation of competency-related information. A claim of exaggerated memory impairment may affect a neuropsychological disability evaluation. In both examples, the opinion about response validity must remain separate from the legal decision: competency, criminal responsibility, eligibility, and credibility are ultimately governed by the relevant legal process and jurisdiction.
The distinction also works in the opposite direction. Someone may exaggerate one symptom while having a genuine disabling disorder. Another person may produce valid performance on one task while struggling with a separate psychological or functional problem. A test result does not erase the broader medical record.
Feigning, Exaggeration, and Invalid Performance Are Different Findings
Pure feigning describes a report of symptoms or deficits that are not present as claimed. Partial malingering describes intentional exaggeration of real symptoms. False attribution describes knowingly linking real symptoms to an event or cause unrelated to them. These categories are conceptual distinctions described in the AAPL guidance; they are not independently established merely by counting test failures.
A validity measure may indicate that responses are inconsistent with the measure's assumptions or with patterns observed in specified reference groups. It cannot directly observe a person's private intention. Intentionality usually requires an inference built from the full factual record and alternatives. Consequently, an examiner can conclude that some results are not interpretable without also concluding that malingering has been proved.
The reverse also matters: passing a particular measure does not establish that every self-report, every interview statement, and every other performance is accurate. Reliability is question-specific, instrument-specific, and limited by its validation evidence.
How Forensic Psychologists Assess Possible Malingering
A defensible evaluation begins with the psycholegal referral question, the relevant period, the examinee's circumstances, and a plan for identifying what would count as corroborating or contradicting evidence. It commonly brings together an interview, direct behavioral observations, appropriately selected standardized measures, clinical and educational records, medical and correctional records where lawfully available, and other relevant collateral sources. An examiner should document the provenance and reliability of those sources.
The AAPL's comprehensive forensic assessment guidance recommends examining potential incentives, conducting a thorough interview, obtaining relevant records, considering observations over time, and supporting any conclusion with multiple factual bases. The APA Specialty Guidelines similarly emphasize scientifically supported procedures, impartiality, limitations, and the appropriate use of assessment data.
An interview can clarify chronology, symptom descriptions, prior care, behavioral functioning, inconsistencies, and alternative hypotheses. Interview behavior can generate questions for investigation. It cannot serve as an intuitive lie detector. Avoiding eye contact, emotional flatness, irritation, hesitation, guardedness, or a confusing account may have many explanations and provides no validated stand-alone diagnosis of feigning.
Records may document the onset and continuity of symptoms, treatment response, prior functioning, and contemporaneous observations. Differences between sources require interpretation: accounts can disagree because memory is imperfect, different observers see different situations, records are incomplete, or actual clinical functioning fluctuates.
Testing provides structured information but demands attention to the specific instrument, its scoring, the population in which it was studied, and the stakes of the assessment. When evidence conflicts, the evaluator should explain the conflict rather than forcing it into a simple genuine-versus-fake conclusion.
What Do Symptom Validity Tests Measure?
Symptom validity tests, or SVTs, seek evidence concerning how a person reports symptoms. Some structured interviews or questionnaire scales assess unusually improbable, atypical, inconsistent, or markedly excessive symptom endorsements relative to reference groups. Depending on the measure, the goal may be to screen for overreporting or to provide a more extensive evaluation of reported psychiatric or somatic symptoms.
A symptom-validity score is a psychometric result about a response pattern, not a direct measure of legal dishonesty. Extreme and unusual experiences sometimes occur in genuine illness. A scale developed for one language, clinical population, or referral context may behave differently in another. The examiner should identify the relevant clinical base rate, the measure's known error rates, possible confounds, and what the validated result can actually support.
The Structured Interview of Reported Symptoms (SIRS) and its second edition (SIRS-2) have been studied in forensic contexts. A meta-analysis of SIRS studies by Green and Rosenfeld found that classification performance varied by methodology and by whether the comparison group consisted of genuine patients or nonclinical participants. Follow-up research on the SIRS-2 describes a trade-off in which efforts to reduce false positive classifications may lower sensitivity.
Self-report inventories such as the Minnesota Multiphasic Personality Inventory family and the Personality Assessment Inventory include validity indicators that can inform assessment of response style. They require trained interpretation and are not interchangeable with a formal assessment of legal capacity or credibility. Their profiles may be informative as one element of an integrated record.
What Do Performance Validity Tests Measure?
Performance validity tests, or PVTs, assess whether performance on selected cognitive tasks can be interpreted as a dependable indicator of the abilities being measured. They are especially relevant to claims involving memory, attention, concentration, or other neurocognitive difficulties. A PVT may be administered as a stand-alone instrument or included as an embedded indicator within a broader battery.
A PVT failure can support the conclusion that particular cognitive scores underestimate ability or are not interpretable in the intended way. It does not establish a specific motive, a diagnosis, or the absence of real cognitive impairment. Genuine impairment and invalid performance may coexist. The examination still needs to establish what the person can do, what can reasonably be inferred from clinical history, and how uncertain results affect the referral question.
The Sherman, Slick, and Iverson criteria discuss multiple validity indicators, convergent discrepancies, redundancy among measures, and alternative explanations. The methodological literature remains actively debated. In particular, Leonhard's 2023 review of statistical problems questions the independence of overlapping validity indicators, while his companion methodological review scrutinizes study reference standards and selection biases. This disagreement makes it especially important to describe the actual evidence rather than treating a numerical cutoff as an infallible verdict.
Common Instruments and What Their Results Can Support
The Miller Forensic Assessment of Symptoms Test (M-FAST) is a brief screening instrument for potentially feigned psychiatric complaints. Screening is a triage function: a positive result prompts appropriate follow-up, while a negative result can reduce concern under conditions resembling those in validation studies. It is not a stand-alone adjudication of whether the examinee deliberately lied. A 2019 meta-analysis investigated the M-FAST's ability to distinguish overreporting groups from comparison groups across multiple study designs.
The Structured Inventory of Malingered Symptomatology (SIMS) is another self-report screening approach. Its performance depends on the population and the studied cutoff. Claims about one setting should not automatically be extended to defendants, people with complex mental illness, or individuals completing an assessment in another language.
The SIRS and SIRS-2 are more extensive structured approaches to psychiatric symptom presentation. Research demonstrates that different versions and classification rules can prioritize avoiding false positives or detecting more suspected cases, with corresponding changes in sensitivity and specificity. The 2022 review of SIRS-2 use in forensic assessment addresses these trade-offs and admissibility considerations.
The Test of Memory Malingering (TOMM) and other PVTs address performance credibility, especially in cognitive assessments. Their results must be analyzed with attention to the examinee's clinical condition and to limitations in the research used to establish classification accuracy. The 2023 methodological review identifies substantial risk-of-bias concerns in early TOMM validation research. That critique informs careful interpretation and does not justify declaring every PVT either worthless or universally accurate.
No instrument on this list has a lawful or scientific mandate to decide criminal guilt, determine competency independently, identify the cause of all symptoms, or establish the person's intentional state without additional evidence.
What the 2026 Evidence Says About Feigning Screens in Competency Evaluations
A particularly relevant new finding comes from the 2026 systematic review and meta-analysis by Krishnan and colleagues, which examined M-FAST, atypical-presentation scales associated with competency assessment, and SIMS in competency-to-stand-trial evaluations. The analysis included 14 research reports with 20 effect sizes and 1,929 participants. It found large differences between overreporting and comparison groups, with reported pooled sensitivities of .87 for the M-FAST and .91 for the atypical-presentation scales. The SIMS evidence base was too sparse for some additional analyses.
The authors concluded that the M-FAST and atypical-presentation scales may help identify examinees who do not need further symptom-validity testing, while positive screening results require follow-up because false positives remain a concern. These are findings about screening and classification within studied samples. They do not prove that a positive result demonstrates intentional deception in an individual defendant.
A different 2026 narrative review by Leonhard examines contextual factors that may undermine confident malingering attributions, including fatigue, stress, trauma history, linguistic and cultural differences, substance use, comorbidity, and interpersonal circumstances. Its conclusions are a narrative synthesis rather than the estimated pooled accuracy of a new test. Together, the two papers illustrate a necessary distinction: a screen can offer useful discrimination, while the interpretation of a specific result remains dependent on case context and the possibility of error.
Sensitivity, Specificity, and the Risk of False Accusation
Sensitivity describes the proportion of reference-standard positive cases that a measure correctly flags. Specificity describes the proportion of reference-standard negative cases that it correctly classifies. A false positive occurs when a person who does not meet the reference criterion is flagged as positive. A false negative occurs when a reference-positive case is missed. These quantities are estimated within particular studies using particular definitions of the reference standard.
Positive predictive value answers a different question: among people with positive results in a defined population, what proportion actually meet the reference condition? It depends strongly on how common that condition is. Estimates of malingering prevalence in forensic settings vary because referral populations, operational criteria, and verification methods vary; a universal prevalence estimate cannot be carried from one setting to another.
Consider a purely hypothetical screening test with 80% sensitivity and 90% specificity in a group of 100 examinees where 10% meet the study's reference definition. The test would identify about 8 of those 10, while incorrectly flagging about 9 of the remaining 90. Among the approximately 17 positive results, roughly 8 would be true positives and 9 false positives. In that illustration, the positive predictive value is about 47%. Those numbers are an arithmetic demonstration, not reported performance values for any instrument discussed here.
Even that illustration simplifies real forensic assessment. The real reference condition may be uncertain; multiple validity indicators can be correlated; cutoffs selected for one group may not transfer to another; and laboratory participants instructed to simulate symptoms may differ from actual people in high-stakes proceedings. Leonhard's two-part methodological review describes why apparent accuracy can be overstated when research design and correlated measures are insufficiently considered.
Why Laboratory and Forensic Samples Are Not Interchangeable
Many test-validation studies use known-groups designs, instructed simulators, or cases classified using other indicators. Instructed simulators can establish that a measure differentiates people told to produce inaccurate symptoms from a comparison group under controlled conditions. This does not guarantee the same classification performance with genuine patients, complex comorbidities, or defendants for whom motivation is inferred rather than experimentally assigned.
Studies of suspected malingering also face a reference-standard problem: there is rarely an independent, infallible way to establish private intent. If the same PVTs or SVTs define who counts as a malingerer and also function as predictors, circularity may inflate apparent validity. Excluding ambiguous cases from analyses can further increase apparent accuracy. Leonhard's 2023 methodological review details these issues.
The importance of clinical comparison samples is demonstrated by the SIRS meta-analysis: genuine psychiatric patients were more likely to be misclassified as feigning than nonclinical comparison participants. A screening method for legal use therefore needs evidence from the kinds of people and circumstances in which it will actually be applied.
Differential Explanations: What May Look Like Feigning?
Psychotic disorders can involve symptoms that sound implausible or are described inconsistently. The proper question is whether the reported pattern is supported by an informed clinical and forensic assessment, including its history, observable course, and other sources. A person with psychosis may also deny or minimize symptoms because of fear, mistrust, stigma, or limited insight. Strange content alone is not evidence of fabrication.
Neurodevelopmental conditions, intellectual disability, acquired brain injury, and substantial cognitive limitations can affect comprehension of test instructions, the pace of testing, recall, and communication. An examiner must distinguish invalid administration or genuinely limited capacity from intentional underperformance. Performance validity research cannot remove the need for the correct norms, accommodations, and instrument selection.
Trauma-related symptoms, dissociation, depression, anxiety, pain, sleep disruption, fatigue, and medication effects may influence both reported experiences and performance. These possible explanations must be considered in light of the actual clinical record rather than assumed to explain every inconsistency. The 2026 differential-diagnosis review highlights how incomplete attention to such factors can create unjustified malingering findings.
Language proficiency, interpreter quality, educational history, cultural norms surrounding distress, and familiarity with psychological testing can also affect answers. An assessment validated among fluent English-speaking adults cannot automatically be treated as equivalently calibrated for an individual evaluated through interpretation or with markedly different educational experience. The APA forensic guidelines require attention to these factors and disclosure when evidence of validity for the person assessed is limited.
Finally, misunderstanding, shame, fear of consequences, ordinary memory errors, defensiveness, or confused communication can produce contradictions without deliberate symptom fabrication. The examiner's task is to compare plausible explanations against the record, not to infer deceit from contradiction alone.
Malingering Versus Factitious Disorder, Somatic Symptoms, and Dissimulation
Factitious disorder involves the deceptive falsification or induction of symptoms associated with presenting oneself as ill, without the same defining external-incentive structure. It is itself a clinical disorder. Malingering is an external-incentive attribution. Research and practice guidelines recognize that differentiating motives can be difficult, particularly when the person's circumstances are complicated or the meaning of an apparent benefit is uncertain.
Somatic symptom disorder and functional neurological symptom disorder involve genuine distress or altered functioning and are not defined by intentional deception. Clinically unexplained symptoms are not, by themselves, feigned symptoms. The absence of an identified biological mechanism or a mismatch between reported disability and a single test does not establish conscious fabrication.
Dissimulation or defensiveness may involve concealing, minimizing, or denying symptoms, sometimes in an attempt to avoid stigma or an adverse legal outcome. This response pattern runs in the opposite direction from exaggeration, and it can complicate evaluation of dangerousness, treatment needs, or decision-making capacity. It is still necessary to distinguish deliberate concealment from limited insight or communication difficulties.
Clinicians and courts should also distinguish inconsistencies in autobiographical memory from evidence of intentional lying. Memory is reconstructive and context-dependent. An inaccurate statement can have multiple causal pathways; the forensic opinion must address the actual evidence available for the asserted one.
Forensic Malingering and Competency to Stand Trial
Competency to stand trial addresses the present functional abilities needed for participation in criminal proceedings under the applicable law. It is a psycholegal question rather than a psychiatric diagnosis. Feigned psychosis or cognitive impairment may be relevant to the evaluator's view of those abilities, but a competency finding depends on the governing legal standard and the person's functioning, not simply on a positive validity screen.
The AAPL competency evaluation guideline emphasizes functional legal abilities, careful documentation, collateral information, and restraint before making a malingering accusation. Current screening research, including the 2026 competency-specific meta-analysis, underscores why positive screens warrant additional inquiry instead of a final finding.
A person may be incompetent without exaggerating symptoms, competent despite having a significant psychiatric disorder, or inconsistent on a validity measure while the examiner remains uncertain about intent. These possibilities demand separate conclusions.
Malingering and Criminal Responsibility or the Insanity Defense
Criminal responsibility evaluations may address the defendant's mental state during an alleged offense, under legal standards that differ by jurisdiction. A present-day interview or test result does not independently reconstruct mental state at the relevant historical moment. Records, documented behavior, contemporaneous accounts, and the legal question itself matter.
The AAPL insanity defense evaluation guideline emphasizes the need to compare the examinee's account with relevant records and reports while maintaining impartiality. It also recognizes that some genuinely ill examinees may conceal symptoms, just as others may exaggerate them. Neither diagnosis nor suspected feigning automatically determines criminal responsibility.
Evidence of intentional symptom fabrication in one part of an evaluation therefore requires a carefully limited statement about its relevance to a particular historical claim. The court or other authorized decision-maker determines whether the applicable legal threshold is met.
Malingering in Civil Litigation and Disability Claims
Civil forensic assessments may involve claimed psychological injury after an accident, compensation for impairment, disability, employment-related questions, or other legally relevant functional limitations. External incentives can be present, but an application for benefits or a lawsuit is an ordinary legal activity and cannot be treated as evidence of wrongdoing.
The AAPL psychiatric disability practice resource discusses the need to integrate clinical records, functioning, symptom history, and examination findings. An expert should distinguish the degree of established impairment from uncertainty about the accuracy of specific self-reported complaints.
Forensic language must be proportionate. A report may be able to state that available cognitive test results cannot reliably estimate the claimed level of impairment. It may be unable to state why performance was invalid. That narrower conclusion can be scientifically useful without imputing dishonest intent.
Cultural Fairness, Disability, and Population Limits
Every instrument has a domain of validation. An accuracy estimate from adult English-speaking defendants at one institution may not apply to adolescents, people with intellectual disability, people with severe psychosis, neurodivergent examinees, people evaluated through an interpreter, or other groups without specific supporting evidence. The test manual, independent replication studies, and relevant professional guidance should govern interpretation.
A responsible expert identifies the comparison group from which a scale's expected patterns or cut scores are derived. If the examinee differs materially from that group, the report should describe the resulting uncertainty. Translation alone does not provide evidence that a test measures the same construct with the same classification accuracy.
The concern extends to the fairness of combining measures. Several apparently independent failures may reflect correlated indicators, shared language demands, or a common underlying limitation rather than multiple independent pieces of evidence. When the quality of subgroup validation is unknown, that fact belongs in the report.
These principles follow the APA's requirements concerning test validity, linguistic appropriateness, disability, and individual differences.
Forensic Ethics: Why Overstatement Is Especially Harmful
An unsupported malingering label can affect access to health care, disability benefits, liberty-related decisions, credibility in proceedings, and the professional treatment an individual subsequently receives. Failing to recognize deliberate misrepresentation can also distort an evaluation. Both directions of error matter, and their consequences are not identical in every case.
A forensic evaluator should disclose the purpose of the examination, the role of the evaluator, relevant limits of confidentiality, and the authorized uses of findings consistent with professional guidance and local law. The evaluator also needs to consider who supplied the records, what may be missing, and how the retaining party's theory of the case might influence interpretation.
Impartiality is a method of practice. It requires evaluating both evidence that supports an impression and evidence that challenges it. An expert should explain uncertainty in concrete terms: the measure's reference population, the limitations of the cutoff, the competing explanations, the quality of collateral records, and the inferential step from noncredible performance to deliberate external-gain motivation.
Under Federal Rule of Evidence 702, admissibility of expert testimony in U.S. federal proceedings turns on sufficient data, reliable methods, and reliable application, among other requirements. This is a legal rule for those proceedings, not a universal psychological definition and not a substitute for the different standards that may govern state, administrative, or international cases.
What a Careful Forensic Report Should Actually Say
A well-reasoned report identifies the referral question and time period, clinical and legal context, examination dates, records reviewed, instruments used, relevant validity and performance findings, the examinee's opportunities to explain discrepancies, and known limits on interpretation. It explains which clinical or functional findings remain reliable and which require caution.
The evaluator can organize conclusions into progressively narrower claims. One type of statement describes observed facts: particular self-reports contradicted specified contemporaneous records. Another reports a psychometric observation: an instrument score crossed a validated screening threshold in an appropriately matched comparison context. A third addresses interpretation: some symptom reports warrant further verification, or certain test scores cannot estimate functional ability reliably. A more serious inference that symptoms were intentionally fabricated for an external incentive requires its own convergent evidentiary support.
The report should explain alternative hypotheses and the reasons they were accepted or discounted. Where evidence is insufficient, an explicit indeterminate conclusion is appropriate. The goal is a defensible answer to the psycholegal question, with the strength of each inference matched to the evidence, as reflected in the AAPL and APA guidance.
What To Do if a Forensic Evaluation Raises Concerns About Malingering
An examinee, attorney, referring agency, or treating professional should begin by identifying the exact conclusion in the report. Was the result a screening flag, an invalid performance indicator, a reason to seek additional records, a formal professional opinion concerning deliberate feigning, or a judicial finding? These are different categories with different consequences.
Questions about fairness may appropriately focus on the instrument's intended purpose, the comparison population, language and disability accommodations, what records were reviewed, whether inconsistent evidence was considered, and what alternative explanations were addressed. A qualified independent reviewer can assess the methods and reasoning when the legal process permits.
Health needs should be evaluated on their own merits. Concerns about response validity do not remove the obligation to assess acute psychiatric or medical problems through appropriate clinical care. Specific legal remedies, disclosure duties, expert challenges, and review procedures depend on jurisdiction and should be addressed through suitably qualified legal counsel.
Common Myths About Malingering
The first myth is that a person involved in litigation has a presumptive reason to fake symptoms. The existence of an incentive is a contextual fact. The additional claims of fabrication and intention require evidence.
The second myth is that unusual psychiatric symptoms reveal a faker. Psychiatric presentations can be complex, fluctuating, and difficult to describe. Symptom improbability measures must be interpreted with reference to clinical populations and known limitations.
The third myth is that one positive test proves intentional malingering. Screening tools and performance measures produce constrained results. The 2026 competency-specific meta-analysis explicitly recommends follow-up for positive screens because false positives occur.
The fourth myth is that genuine illness and exaggeration are mutually exclusive. Someone can have a well-documented disorder and inaccurately describe an aspect of their symptoms or functioning. Each claim should be examined separately.
The fifth myth is that trained interviewers can reliably identify intentional lying from eye movements, awkward body language, or hesitation. These observations have many explanations and do not replace structured, corroborated forensic assessment. Professional guidance emphasizes records, validated methods, contextual interpretation, and corroboration.
Frequently Asked Questions
Is malingering a mental disorder?
No. The DSM-5-TR lists malingering as a condition that may be a focus of clinical attention, not as a mental disorder. In forensic psychology the term describes a proposed pattern of intentional symptom misrepresentation associated with external incentives.
Can a forensic psychologist prove someone is malingering?
A forensic psychologist may offer a supported professional opinion after evaluating appropriate records, interviews, observations, tests, incentives, and competing explanations. Scientific findings have error rates and inferential limits. Legal fact-finding belongs to the authorized court or decision-maker under the applicable jurisdiction.
Can a person with a real mental illness also malinger?
Yes. Genuine symptoms and intentional exaggeration can coexist. The presence of inconsistency cannot nullify a well-supported diagnosis or establish that the entire clinical presentation is fabricated.
Does failing the TOMM or another validity test mean someone is lying?
A failed performance validity indicator may make some cognitive scores difficult to interpret as estimates of actual capacity. Its meaning depends on the instrument, cutoff, validation population, medical and cognitive conditions, and the entire profile. It is not an independent measurement of motive or intent.
Are M-FAST and SIMS reliable tests for malingering?
They are established screening approaches with research evidence and important limitations. Results are sensitive to the setting, comparison groups, and thresholds. A 2026 review focused on competency evaluations found useful screening discrimination for some methods while emphasizing the need to investigate positive results further.
Can symptoms be exaggerated unintentionally?
Self-reports can be inaccurate because of memory problems, misunderstanding, fear, emotional distress, or differences in symptom interpretation. Exaggeration in the descriptive sense does not always establish a deliberate strategy. Intent is an additional forensic inference.
How common is malingering in forensic settings?
There is no single rate applicable to all defendants, patients, disability claimants, or correctional populations. Estimates depend on the referral context, operational definition, source of information, and research method. Because an uncontested reference standard is often unavailable, prevalence claims require particular care.
Does malingering determine competency or an insanity defense?
No. Competency and criminal responsibility are different psycholegal questions governed by jurisdiction-specific law. An evaluation of response validity may inform the evidence available for those questions, but it does not replace functional assessment, historical reconstruction, or the legal standard.
Can an invalid test score mean a real psychiatric problem is absent?
No. Invalidity limits the inferences that may be drawn from the affected result. Other clinical findings, records, and observations can remain relevant to the question of genuine illness and functioning.
Why do experts disagree about malingering tests?
Disagreement concerns research designs, reference standards, false positive risk, thresholds, test dependence, and how far psychometric results can support an attribution of deliberate intent. The 2023 statistical critique and the 2020 multidimensional criteria demonstrate why methods and inferential rules deserve explicit discussion.
The Central Principle
Malingering assessment is a process of disciplined evidence interpretation. Interview findings, validity scales, cognitive performance, documented functioning, and external incentives answer different questions. The responsible forensic opinion brings those questions together while preserving the boundaries between a psychological construct, a clinical diagnosis, an assessment result, inferred intention, legal capacity, and a legal finding.
The most consequential error is to confuse a test indication with proof of motive. A scientifically sound conclusion states what was observed, how accurately the method is known to classify comparable cases, which alternative explanations remain plausible, and how much the available evidence can support in the legal setting at issue.
For broader context, see Forensic Psychological Assessment: Purpose, Methods, and Limits.
Related Articles
References
American Academy of Psychiatry and the Law. (2007). AAPL practice guideline for the forensic psychiatric evaluation of competence to stand trial. Journal of the American Academy of Psychiatry and the Law, 35(4 Supplement), S3–S72. Official journal guideline.
American Academy of Psychiatry and the Law. (2014). AAPL practice guideline for forensic psychiatric evaluation of defendants raising the insanity defense. Journal of the American Academy of Psychiatry and the Law, 42(4 Supplement), S3–S76. Official journal guideline.
American Academy of Psychiatry and the Law. (2015). AAPL practice guideline for the forensic assessment. Journal of the American Academy of Psychiatry and the Law, 43(2 Supplement), S3–S53. Official journal guideline.
American Psychological Association. (2011). Specialty guidelines for forensic psychology. APA professional guidelines.
Detullio, D., Messer, S. C., Kennedy, T. D., & Millen, D. H. (2019). A meta-analysis of the Miller Forensic Assessment of Symptoms Test (M-FAST). Psychological Assessment. https://doi.org/10.1037/pas0000753.
Green, D., & Rosenfeld, B. (2011). Evaluating the gold standard: A review and meta-analysis of the Structured Interview of Reported Symptoms. Psychological Assessment, 23(1), 95–107. https://doi.org/10.1037/a0021149.
Krishnan, N., Trood, M. D., Ruffles, J., Blake, G., & Ogloff, J. R. P. (2026). Are feigning screens “competent to stand trial”? A systematic review and meta-analysis of the Miller Forensic Assessment of Symptoms Test, Atypical Presentation Scales, and Structured Inventory of Malingered Symptomatology. Law and Human Behavior, 50(4), 335–360. https://doi.org/10.1037/lhb0000661.
Leonhard, C. (2023a). Review of statistical and methodological issues in the forensic prediction of malingering from validity tests: Part I—Statistical issues. Neuropsychology Review, 33, 581–603. https://doi.org/10.1007/s11065-023-09601-7.
Leonhard, C. (2023b). Review of statistical and methodological issues in the forensic prediction of malingering from validity tests: Part II—Methodological issues. Neuropsychology Review, 33, 604–623. https://doi.org/10.1007/s11065-023-09602-6.
Leonhard, C. (2026). A narrative review of differential diagnoses in the forensic determination of malingering based on discrepancies and scores on performance and symptom validity tests. Journal of Forensic and Legal Medicine, 119, 103114. https://doi.org/10.1016/j.jflm.2026.103114.
Sherman, E. M. S., Slick, D. J., & Iverson, G. L. (2020). Multidimensional malingering criteria for neuropsychological assessment: A 20-year update of the malingered neuropsychological dysfunction criteria. Archives of Clinical Neuropsychology, 35(6), 735–764. https://doi.org/10.1093/arclin/acaa019.
U.S. Federal Rules of Evidence. Rule 702: Testimony by expert witnesses (as amended). Federal legal text.