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Assessing Malingering and Deception in Forensic, Judicial and Clinical Contexts: Are Various Communications “Congruent”?

Medico Legal

By Koch HCH, Newns K, Boyd T & Peters J


Professionals working in custodial, forensic, criminal, civil and mental health contexts regularly interview individuals to establish diagnosis, treatment requirements, medico-legal opinion, reliability and truthfulness. A common aspiration is to establish some form of ‘holy grail of detecting truth or deception which then informs decision making, whether it be forensic, clinical or judicial (Koch, 2016; Oxburgh et al, 2016).

The social psychology of lying and deceit detection indicates that deceiving others is an ‘emotional part of everyday social interaction’ (Grant et al, 2016). Deceptive detection is crucial both in terms of forensic crime detection but also in civil contexts where it is possible that claimants misrepresent what has occurred or types of alleged PI or loss. Recently personal injury claimants have faced large bills in the court when their PI claims were dismissed having been found to be fundamentally dishonest (Litigation Funding, 2016).

Most professionals believe they can detect deception and sometimes ‘common sense’ prevails to reinforce this belief. However, counter-intuitive evidence occasionally emerges which illustrates this is often not the case. A recent study (Leach et al, 2016) examined the assumption that seeing a person’s face (uncovered) was necessary to detect deception. Observers’ performance (in the UK, Canada and the Netherlands) was better when witnesses wore facial covering (i.e. nijabs or hijabs) than when witnesses did not wear veils. These findings suggest that, contrary to judicial and public opinion, facial veils did not interfere with, and may improve, the ability to detect deception.

Research indicates that people vary in their ability to lie, but also, people are not consistently good at lie detection. Hence the dilemma! When people lie, they are typically uncomfortable if lying to close friends, but less so when talking to strangers. People lie to give a positive impression, obtain some sort of advantage, to evade penalties, and also to maintain the equanimity of a relationship, rather than ‘rock the boat’ (Rix, 2011). The social psychological research indicates there are different types of lies, liars and gender, age and personality trait differences between those who lie (Halligan et al 2003).

There are at least six distinct response styles of unreliability or dissimulation (Rogers, 1997). These include:
• Malingering
• Defensiveness
• Non-engaged irrelevant responsiveness
• Random responding
• Honest but factually incorrect
• Hybrid responding (combination of any of the above)

A key aspect of deception detection is the importance of assessing verbal and non-verbal behaviour. Non-verbal behaviour is more difficult to control than verbal behaviour (Vriz et al, 2016) with issues arising in emotional control (guilt, fear, excitement), context complexity (lying being a cognitively complex task), and behavioural control (unsuccessful attempts to suppress signs of lying). An example of some non-verbal behaviours evident at times during lying and deception is illustrated in Fig. I below (Vriz, 2000).

Fig I Examples of Non-Verbal Behaviour During Deception (Vriz, 2000)

Vocal Characteristics
1. Speech hesitations: use of words ‘ah’, ‘um’, ‘er’ and so on
2. Speech errors: word and/or sentence repetition, sentence change, sentence incompletions, slips of the tongue, and so on
3. Latency period: period of silence between question and answer

Facial Characteristics
1. Gaze: avoiding the face of the conversation partner
2. Blinking: blinking of the eyes

Movements
1. Self-manipulations: scratching the head
2. Shifting position: movements made to change the sitting position (usually accompanied by trunk and foot/leg movements)

Data concerning these characteristics show a conflicting pattern i.e. the presence of one or two specific characteristics is not a prima facie indication of lying. There is no clear, binary relationship between nonverbal characteristics and lying.

Lying is logically difficult. The more complicated a lie is the greater non-verbal characteristics and logical inconsistencies are evident.

The degree of motivation also affects lying success. People who are highly motivated to get away with their lies may behave differently to those who have less personal investment in the outcome of their lying. Hence different motivational effects are found in an offender group, on the one hand, e.g. evade or reduce sentence, accelerate release from custody, and mental-health or civil claimant groups, on the other (e.g. to gain treatment, empathy and compensation).

Ability to detect lies

The ability to detect differences between liars and non-liars is variable. There is no one, consistently successful, ‘cognitive heuristic’ which governs the detection of lying, and potential judgments about lying and liars is adversely affected by not taking individual differences in behaviour into account e.g. social anxiety. Characteristics of truth-tellers and of good liars include verbal and non-verbal behaviour that is congruent and believable.

Vriz et al (2016) defined a set of guidelines for the detection of deception via behavioural cues, some examples are illustrated in Fig. 2 below:

Fig 2
Deception via behavioural cues (Vriz, 2016)

1. Lies may only be detectable via non-verbal cues if the liar experiences fear, guilt or excitement, or if the lie is difficult to fabricate.
2. It is important to pay attention to mismatches between speech content and non-verbal behaviour, and to try to explain these mismatches.
3. Attention should be directed towards deviations from a person’s ‘normal’ or usual patterns of behaviour, if these are known. Each deviation may indicate that the person is lying.
4. The judgment of untruthfulness should only be made when all other possible explanations have been negated.
5. A person suspected of deception should be encouraged to talk. This is necessary to negate the alternative explanations of a person’s behaviour. Moreover, the more a liar talks, the more likely it is that they will finally give their lies away via verbal and/or non-verbal cues.
6. There are stereotypical ideas about cues to deception (such as gaze aversion, fidgeting, and so on), which research has shown to be unreliable indicators of deception. Not everyone will exhibit these cues during deception, and the presence of such cues may indicate deception, but does not do so in every case.

The empirical development of verbal techniques to measure the veracity of statements indicated that deceptive statements often included shorter, more implausible and non-self-references (due to lack of personal experience). This led to the most popular technique to date for assessing deception – the Statement Validity Assessment (Kohnken and Steller, 1988). This was developed primarily in a forensic setting (sexual offences; child abuse context) and consisted of a structured interview, a criteria-based context analysis of the contexts of a statement, and a set of validity-checking questions. The context criteria for analysing statements in clinical consideration of the several characteristics (Vriz, 2000) shown in Figure 3 below:
Fig 3
Some examples of content criteria for statement analysis
General characteristics
1. Logical structure
2. Unstructured production
3. Quantity of details
Specific contents
4. Contextual embedding
5. Descriptions of interactions
6. Reproduction of conversation
7. Unexpected complications during the incident
8. Unusual details
9. Superfluous details
10. Accounts of subjective mental state
Motivation-related contents
11. Spontaneous corrections
12. Admitting lack of memory
13. Raising doubts about one’s own testimony

Each of the above criteria may contribute to the assessment of veracity.
The validity-related checklist developed is shown below:

Fig 4
Examples of Validity Check-list
Psychological characteristics
1. Inappropriateness of language and knowledge
2. Inappropriateness of affect
3. Susceptibility to suggestion
Motivation
4. Questionable motives to report
5. Questionable context of the original disclosure or report
6. Pressures to report falsely (e.g. avoid detection; obtain compensation)
Investigative questions
7. Inconsistency with the laws of nature
8. Inconsistency with other statements
9. Inconsistency with other evidence

The utilisation of statement validity assessment is accepted as evidence in both criminal and civil courts in several countries but is not without problems, namely frequency of false/negative classification, subjectivity (of evaluator), and lack of other confirmatory evidence.

It has been argued (Vriz et al, 2016) that memories of real experiences are likely to contain perceptual information (visual details, sounds, smells, tastes and physical sensation), contextual information (e.g. when and where something occurred) and affective information (e.g. detail about how someone felt during the event). These memories are typically ‘clear, strong and vivid’. Untrue descriptions are typically more vague and less concrete. Studies have indicated that reality monitoring might be more useful for analysing adults’ statements than for studying children’s statement, and for analysing statements about recent rather than older events.
Psychometric Testing for deception.

Psychometric testing and measurement falls into two categories – general testing (e.g. MMPI, 16PF, SIMS), and forensic neuropsychological testing. The former has received a mixed press both in terms of its validity in detecting deception or lying and also in terms of its time efficiency.

Clinical neuropsychological testing has, conversely, received better reviews both in terms of identifying deception and malingering and perhaps, of greater utility, assessment of sub-optimal effort and motivation (Thompson, 2011) and has rightfully led to a higher degree of expectation in terms of forensic, clinical and courtroom knowledge, objectivity and utility (Richard, Geiger and Tussey, 2015).

There are several psychometric assessments which have been used as an aid to detect malingering: The Minnesota Multiphasic Personality Inventory (MMPI-2), the Structured Interview of Reported Symptoms (SIRS), and the Structured Inventory of Malingered Symptomatology (SIMS) (See Halligan et al, 2003 for details). Studies have found that malingerers can “successfully” evade detection on measures using validity scales in 44% to 80% of occasions (Carmody and Crossman, 2005; Peace and Masliuk, 2011 – cited in Peace & Richards, 2014), hence the empirical ambivalence for using these instrument, both forensically and clinically.

A more recent psychometric innovation which has gained credence in the civil claimant context has been that of Interrogative Suggestibility (Frumkin, 2016). False confessions and inaccurate evidence can frequently be based on an individual’s over-suggestibility and intolerance of uncertainty, resulting in the giving of misleading and inaccurate information. This has been measured by Gudjonsson (2013) andfocuses on how likely a person is to change his response under pressure or interrogation. The applicability of suggestibility assessment as a factor in both criminal and personal injury civil cases is gaining credence.

Can professionals be trained to be good lie detectors?
Many individuals are capable of behaving unethically, being deceitful and committing fraud. This varies from habitual crime to one occasional fraudulent action. Fraud and deception impacts on all of us in terms of costs built into subsequent insurance. Hence proactive skills and awareness of how to detect deception continues to have a high priority in the work of forensic, judicial and clinical professionals.

Training in the use of content analysis and statement validity interviewing increases the effectiveness of reliability assessment and deception detection. Training in non-verbal behaviour identification is useful but it is a complex task to apply this in actual deception detection, due to the inconsistency of non-verbal indicators of deception in each and every liar. In addition to the key overriding primary skill of listening and establishing if the several, various communications from an individual are congruent and consistent with a potential ‘true story’, the professional attempting to catch a liar needs the following micro skills:
• A suspicious, challenging attitude
• A probing, repetitious, questioning attitude
• A withholding attitude (i.e. non-disclosure of what is already known)
• Well researched, background information prior to interview

To achieve this level of communication skill requires an awareness and confidence in the micro-skills of face-to-face communication and an ability to mentally accommodate different types of interpersonal cues or behaviour in the interviewee before reaching a conclusion about truthfulness. (Koch, 2016).

Several recognised psychological guidelines (in DSMV) have potential components of deception associated with them (e.g. sociopathy and other personality disorders, amnesia, substance abuse and PTSD). Four main detection strategies for feigned psychopathology include: identification of rare symptoms, indiscriminate symptom endorsement, obvious symptoms and improbable symptoms. (Rogers, 1997)

The clinician in a civil justice or mental health context must integrate an array of clinical findings on the issue of dissimulation. This includes assessing:
1. the strength and consistency of results across various measures and
2. the absence of alternative explanations (Rogers, 1997)

Legal and professional issues
The use of the term ‘malingering’ or ‘liar’ is a difficult and complex issue. Relevant professional/legal issues pertaining to this include: -
1. In what proportion of forensic and civil cases is the issue of dissimulation part of a clinician’s psycholegal conclusions?
2. Given the far-reaching consequences of forensic and medico-legal evaluations, are different clinical criteria needed to differentiate dissimulators from others?
3. What influences do descriptions of dissimulation within clinical reports have on legal disposition or clinical treatment.
4. In public policy terms, what errors (false positives or false negatives) is the criminal or civil justice system willing to tolerate with respect to malingering and defensiveness?
Experience and research with individuals in forensic contexts (Rogers, 1997), civil claimants and mental health patients (Koch, 2016) suggest that these are three types of continua on which to classify malingering and defensiveness. These are shown in Fig VI below with descriptions (Rogers, 1997):

Fig VI
A. Unreliability: Continuum of Reliable – Limited Reliability – Without Reliability
1. Self-report with limited reliability: The patient answers most inquiries with a fair degree of accuracy, but volunteers little or nothing and may distort or evade on circumscribed topics. 2. Self-report without reliability: The patient, through guardedness, exaggeration, or denial of symptoms, convinces the clinician that his or her responses are inaccurate. Such cases may be suspected of malingering or defensiveness, although the patient’s intent cannot be unequivocally established.
B. Malingering:
Continuum of Truthful – Mild Malingering – Moderate Malingering – Severe Malingering
1. Mild malingering: There is unequivocal evidence that the patient is attempting to malinger, primarily through exaggeration. The degree of distortion is minimal and plays only a minor role in differential diagnosis.
2. Moderate malingering: The patient, either through exaggeration or fabrication, attempts to present him- or herself as considerably more disturbed than this is the case. These distortions may be limited to either a few critical symptoms (e.g. the fabrication of hallucinations) or represent an array of lesser distortions.
3. Severe, malingering: The patient is extreme in his or her fabrication of symptoms to the point that the presentation is fantastic or preposterous.
C. Defensiveness
Continuum of Not Defensive – Mild Defensiveness – Moderate Defensiveness – Severe Defensiveness 1. Mild defensiveness: There is unequivocal evidence that the patient is attempting to minimize the severity but not the presence of his or her psychological problems. These distortions are minimal in degree and of secondary importance in establishing a differential diagnosis.
2. Moderate defensiveness: The patient minimizes or denies substantial psychological impairment. This defensiveness may be limited to either a few critical symptoms (e.g. paedophilic interest) or represent lesser distortions across an array of symptomatology.
3. Severe defensiveness: The patient denies the existence of any psychological problems or symptoms. This categorical denial includes common foibles and minor emotional difficulties that most healthy individuals have experienced and would acknowledge.

Evidential certainty in this crucial area of deception is a complex and multi-layered issue. It is one of the most challenging aspects of forensic, judicial and clinical findings about deceptions can be best seen on the continuum: Definite unsupportive.
Degree of certainty is and illustrated in Fig VII below.

Fig VII Degree of Certainty in Findings (Rogers, 1997; Koch, 2016)
Level of certainty - Unsupported
Clinical criteria
Non-significant or conflicting research findings.
Speculative
Conclusions that are consistent with accepted theory and supported by one or two studies of limited generalizability.
Tentative
Research studies consistently show statistical significance in the expected direction, but have little or no practical value in classifying individuals.
Probable
Research studies consistently establish statistical significance in which cutting score, measures of central tendency, or a similar statistic accurately differentiate between at least 75% of the criterion groups.
Definite
Accurate classification of 90% or more of individual person based on extensive, cross-validated research. Findings are congruent with accepted theory.

As a counterpoint to the concept of certainty in deception detection, the ‘unanticipated questions approach’ (Sooniste et al, 2016) indicates that liars and truth tellers differ in their ability to answer unexpected questions during an interview i.e. liars competence in answering unanticipated questions is impaired as they, unlike truth tellers cannot rely on simple recall or on prepared answers, and hence appear inconsistent, and lacking in valid detail. This fascinating research illustrates a new wave of detection research and practice characterised by asking questions strategically in order to elicit cues to deception and truth.

Conclusion
Practitioners and post graduate students in forensic and clinical psychology all need to be cognizant of the multi factorial nature and complexity of deception detection (Myklebust et al, 2016; Kane & Dvoskin, 2011). Initial identification of one or more characteristics mentioned above need to be followed up and backed up by further evidence before a reliable assessment of deceptiveness in one or more contexts can be substantiated. As has been stated, there is no one ‘holy grail’ predictor of deception. Instead, the experienced forensic or clinical practitioner builds up an impression of congruence or incongruence of many communications and uses this as the basis and justification for opinions on deception. The use of fabrication, exaggeration or malingering is typically a matter for the courts to decide but they require expert assistance. Continuing professional development in this area includes awareness of research and communication skills training in detection deception, using role play discussion and written statement analysis.

Understanding micro-expressions in verbal, non-verbal, and written communications is the key – analysing its subtlety in the challenge for the criminal and civil justice systems, and police and security services, as they increase confidence and competence in investigative interviewing (Westra and Powell, 2016).

References
Koch HCH (2016) Legal Mind: Contemporary Issues in Psychological Injury & Law. Expert Witness Publications, Manchester.

Oxburgh G, Myklebust T, Grant T and Milne R (2016) Communication in Investigative and Legal Contexts. Wiley. London.

A full list of references can be obtained from the first author.

The authors regularly provide medico-legal reporting clinics in Cheltenham and London (Hugh Koch), Cambridge, Luton, Peterborough and Newmarket, Coventry, Leicester and Rugby (Katie Newns, Tom Boyd and Jill Peters) and can all be contacted via www.hughkochassociates.co.uk.

I am grateful for helpful comments from Professor Michael Brookes, Professor of Forensic Psychiatry. Birmingham City University.

By Koch HCH, Newns K, Boyd T & Peters J

By Koch HCH, Newns K, Boyd T & Peters J

Page 2

Professionals working in custodial, forensic, criminal, civil and mental health contexts regularly interview individuals to establish diagnosis, treatment requirements, medico-legal opinion, reliability and truthfulness. A common aspiration is to establish some form of ‘holy grail of detecting truth or deception which then informs decision making, whether it be forensic, clinical or judicial (Koch, 2016; Oxburgh et al, 2016).

The social psychology of lying and deceit detection indicates that deceiving others is an ‘emotional part of everyday social interaction’ (Grant et al, 2016). Deceptive detection is crucial both in terms of forensic crime detection but also in civil contexts where it is possible that claimants misrepresent what has occurred or types of alleged PI or loss. Recently personal injury claimants have faced large bills in the court when their PI claims were dismissed having been found to be fundamentally dishonest (Litigation Funding, 2016).

Most professionals believe they can detect deception and sometimes ‘common sense’ prevails to reinforce this belief. However, counter-intuitive evidence occasionally emerges which illustrates this is often not the case. A recent study (Leach et al, 2016) examined the assumption that seeing a person’s face (uncovered) was necessary to detect deception. Observers’ performance (in the UK, Canada and the Netherlands) was better when witnesses wore facial covering (i.e. nijabs or hijabs) than when witnesses did not wear veils. These findings suggest that, contrary to judicial and public opinion, facial veils did not interfere with, and may improve, the ability to detect deception.

Research indicates that people vary in their ability to lie, but also, people are not consistently good at lie detection. Hence the dilemma! When people lie, they are typically uncomfortable if lying to close friends, but less so when talking to strangers. People lie to give a positive impression, obtain some sort of advantage, to evade penalties, and also to maintain the equanimity of a relationship, rather than ‘rock the boat’ (Rix, 2011). The social psychological research indicates there are different types of lies, liars and gender, age and personality trait differences between those who lie (Halligan et al 2003).

There are at least six distinct response styles of unreliability or dissimulation (Rogers, 1997). These include:
• Malingering
• Defensiveness
• Non-engaged irrelevant responsiveness
• Random responding
• Honest but factually incorrect
• Hybrid responding (combination of any of the above)

A key aspect of deception detection is the importance of assessing verbal and non-verbal behaviour. Non-verbal behaviour is more difficult to control than verbal behaviour (Vriz et al, 2016) with issues arising in emotional control (guilt, fear, excitement), context complexity (lying being a cognitively complex task), and behavioural control (unsuccessful attempts to suppress signs of lying). An example of some non-verbal behaviours evident at times during lying and deception is illustrated in Fig. I below (Vriz, 2000).

Fig I Examples of Non-Verbal Behaviour During Deception (Vriz, 2000)

Vocal Characteristics
1. Speech hesitations: use of words ‘ah’, ‘um’, ‘er’ and so on
2. Speech errors: word and/or sentence repetition, sentence change, sentence incompletions, slips of the tongue, and so on
3. Latency period: period of silence between question and answer

Facial Characteristics
1. Gaze: avoiding the face of the conversation partner
2. Blinking: blinking of the eyes

Movements
1. Self-manipulations: scratching the head
2. Shifting position: movements made to change the sitting position (usually accompanied by trunk and foot/leg movements)

Data concerning these characteristics show a conflicting pattern i.e. the presence of one or two specific characteristics is not a prima facie indication of lying. There is no clear, binary relationship between nonverbal characteristics and lying.

Lying is logically difficult. The more complicated a lie is the greater non-verbal characteristics and logical inconsistencies are evident.

The degree of motivation also affects lying success. People who are highly motivated to get away with their lies may behave differently to those who have less personal investment in the outcome of their lying. Hence different motivational effects are found in an offender group, on the one hand, e.g. evade or reduce sentence, accelerate release from custody, and mental-health or civil claimant groups, on the other (e.g. to gain treatment, empathy and compensation).

Ability to detect lies

The ability to detect differences between liars and non-liars is variable. There is no one, consistently successful, ‘cognitive heuristic’ which governs the detection of lying, and potential judgments about lying and liars is adversely affected by not taking individual differences in behaviour into account e.g. social anxiety. Characteristics of truth-tellers and of good liars include verbal and non-verbal behaviour that is congruent and believable.

Vriz et al (2016) defined a set of guidelines for the detection of deception via behavioural cues, some examples are illustrated in Fig. 2 below:

Fig 2
Deception via behavioural cues (Vriz, 2016)

1. Lies may only be detectable via non-verbal cues if the liar experiences fear, guilt or excitement, or if the lie is difficult to fabricate.
2. It is important to pay attention to mismatches between speech content and non-verbal behaviour, and to try to explain these mismatches.
3. Attention should be directed towards deviations from a person’s ‘normal’ or usual patterns of behaviour, if these are known. Each deviation may indicate that the person is lying.
4. The judgment of untruthfulness should only be made when all other possible explanations have been negated.
5. A person suspected of deception should be encouraged to talk. This is necessary to negate the alternative explanations of a person’s behaviour. Moreover, the more a liar talks, the more likely it is that they will finally give their lies away via verbal and/or non-verbal cues.
6. There are stereotypical ideas about cues to deception (such as gaze aversion, fidgeting, and so on), which research has shown to be unreliable indicators of deception. Not everyone will exhibit these cues during deception, and the presence of such cues may indicate deception, but does not do so in every case.

The empirical development of verbal techniques to measure the veracity of statements indicated that deceptive statements often included shorter, more implausible and non-self-references (due to lack of personal experience). This led to the most popular technique to date for assessing deception – the Statement Validity Assessment (Kohnken and Steller, 1988). This was developed primarily in a forensic setting (sexual offences; child abuse context) and consisted of a structured interview, a criteria-based context analysis of the contexts of a statement, and a set of validity-checking questions. The context criteria for analysing statements in clinical consideration of the several characteristics (Vriz, 2000) shown in Figure 3 below:
Fig 3
Some examples of content criteria for statement analysis
General characteristics
1. Logical structure
2. Unstructured production
3. Quantity of details
Specific contents
4. Contextual embedding
5. Descriptions of interactions
6. Reproduction of conversation
7. Unexpected complications during the incident
8. Unusual details
9. Superfluous details
10. Accounts of subjective mental state
Motivation-related contents
11. Spontaneous corrections
12. Admitting lack of memory
13. Raising doubts about one’s own testimony

Each of the above criteria may contribute to the assessment of veracity.
The validity-related checklist developed is shown below:

Fig 4
Examples of Validity Check-list
Psychological characteristics
1. Inappropriateness of language and knowledge
2. Inappropriateness of affect
3. Susceptibility to suggestion
Motivation
4. Questionable motives to report
5. Questionable context of the original disclosure or report
6. Pressures to report falsely (e.g. avoid detection; obtain compensation)
Investigative questions
7. Inconsistency with the laws of nature
8. Inconsistency with other statements
9. Inconsistency with other evidence

The utilisation of statement validity assessment is accepted as evidence in both criminal and civil courts in several countries but is not without problems, namely frequency of false/negative classification, subjectivity (of evaluator), and lack of other confirmatory evidence.

It has been argued (Vriz et al, 2016) that memories of real experiences are likely to contain perceptual information (visual details, sounds, smells, tastes and physical sensation), contextual information (e.g. when and where something occurred) and affective information (e.g. detail about how someone felt during the event). These memories are typically ‘clear, strong and vivid’. Untrue descriptions are typically more vague and less concrete. Studies have indicated that reality monitoring might be more useful for analysing adults’ statements than for studying children’s statement, and for analysing statements about recent rather than older events.
Psychometric Testing for deception.

Psychometric testing and measurement falls into two categories – general testing (e.g. MMPI, 16PF, SIMS), and forensic neuropsychological testing. The former has received a mixed press both in terms of its validity in detecting deception or lying and also in terms of its time efficiency.

Clinical neuropsychological testing has, conversely, received better reviews both in terms of identifying deception and malingering and perhaps, of greater utility, assessment of sub-optimal effort and motivation (Thompson, 2011) and has rightfully led to a higher degree of expectation in terms of forensic, clinical and courtroom knowledge, objectivity and utility (Richard, Geiger and Tussey, 2015).

There are several psychometric assessments which have been used as an aid to detect malingering: The Minnesota Multiphasic Personality Inventory (MMPI-2), the Structured Interview of Reported Symptoms (SIRS), and the Structured Inventory of Malingered Symptomatology (SIMS) (See Halligan et al, 2003 for details). Studies have found that malingerers can “successfully” evade detection on measures using validity scales in 44% to 80% of occasions (Carmody and Crossman, 2005; Peace and Masliuk, 2011 – cited in Peace & Richards, 2014), hence the empirical ambivalence for using these instrument, both forensically and clinically.

A more recent psychometric innovation which has gained credence in the civil claimant context has been that of Interrogative Suggestibility (Frumkin, 2016). False confessions and inaccurate evidence can frequently be based on an individual’s over-suggestibility and intolerance of uncertainty, resulting in the giving of misleading and inaccurate information. This has been measured by Gudjonsson (2013) andfocuses on how likely a person is to change his response under pressure or interrogation. The applicability of suggestibility assessment as a factor in both criminal and personal injury civil cases is gaining credence.

Can professionals be trained to be good lie detectors?
Many individuals are capable of behaving unethically, being deceitful and committing fraud. This varies from habitual crime to one occasional fraudulent action. Fraud and deception impacts on all of us in terms of costs built into subsequent insurance. Hence proactive skills and awareness of how to detect deception continues to have a high priority in the work of forensic, judicial and clinical professionals.

Training in the use of content analysis and statement validity interviewing increases the effectiveness of reliability assessment and deception detection. Training in non-verbal behaviour identification is useful but it is a complex task to apply this in actual deception detection, due to the inconsistency of non-verbal indicators of deception in each and every liar. In addition to the key overriding primary skill of listening and establishing if the several, various communications from an individual are congruent and consistent with a potential ‘true story’, the professional attempting to catch a liar needs the following micro skills:
• A suspicious, challenging attitude
• A probing, repetitious, questioning attitude
• A withholding attitude (i.e. non-disclosure of what is already known)
• Well researched, background information prior to interview

To achieve this level of communication skill requires an awareness and confidence in the micro-skills of face-to-face communication and an ability to mentally accommodate different types of interpersonal cues or behaviour in the interviewee before reaching a conclusion about truthfulness. (Koch, 2016).

Several recognised psychological guidelines (in DSMV) have potential components of deception associated with them (e.g. sociopathy and other personality disorders, amnesia, substance abuse and PTSD). Four main detection strategies for feigned psychopathology include: identification of rare symptoms, indiscriminate symptom endorsement, obvious symptoms and improbable symptoms. (Rogers, 1997)

The clinician in a civil justice or mental health context must integrate an array of clinical findings on the issue of dissimulation. This includes assessing:
1. the strength and consistency of results across various measures and
2. the absence of alternative explanations (Rogers, 1997)

Legal and professional issues
The use of the term ‘malingering’ or ‘liar’ is a difficult and complex issue. Relevant professional/legal issues pertaining to this include: -
1. In what proportion of forensic and civil cases is the issue of dissimulation part of a clinician’s psycholegal conclusions?
2. Given the far-reaching consequences of forensic and medico-legal evaluations, are different clinical criteria needed to differentiate dissimulators from others?
3. What influences do descriptions of dissimulation within clinical reports have on legal disposition or clinical treatment.
4. In public policy terms, what errors (false positives or false negatives) is the criminal or civil justice system willing to tolerate with respect to malingering and defensiveness?
Experience and research with individuals in forensic contexts (Rogers, 1997), civil claimants and mental health patients (Koch, 2016) suggest that these are three types of continua on which to classify malingering and defensiveness. These are shown in Fig VI below with descriptions (Rogers, 1997):

Fig VI
A. Unreliability: Continuum of Reliable – Limited Reliability – Without Reliability
1. Self-report with limited reliability: The patient answers most inquiries with a fair degree of accuracy, but volunteers little or nothing and may distort or evade on circumscribed topics. 2. Self-report without reliability: The patient, through guardedness, exaggeration, or denial of symptoms, convinces the clinician that his or her responses are inaccurate. Such cases may be suspected of malingering or defensiveness, although the patient’s intent cannot be unequivocally established.
B. Malingering:
Continuum of Truthful – Mild Malingering – Moderate Malingering – Severe Malingering
1. Mild malingering: There is unequivocal evidence that the patient is attempting to malinger, primarily through exaggeration. The degree of distortion is minimal and plays only a minor role in differential diagnosis.
2. Moderate malingering: The patient, either through exaggeration or fabrication, attempts to present him- or herself as considerably more disturbed than this is the case. These distortions may be limited to either a few critical symptoms (e.g. the fabrication of hallucinations) or represent an array of lesser distortions.
3. Severe, malingering: The patient is extreme in his or her fabrication of symptoms to the point that the presentation is fantastic or preposterous.
C. Defensiveness
Continuum of Not Defensive – Mild Defensiveness – Moderate Defensiveness – Severe Defensiveness 1. Mild defensiveness: There is unequivocal evidence that the patient is attempting to minimize the severity but not the presence of his or her psychological problems. These distortions are minimal in degree and of secondary importance in establishing a differential diagnosis.
2. Moderate defensiveness: The patient minimizes or denies substantial psychological impairment. This defensiveness may be limited to either a few critical symptoms (e.g. paedophilic interest) or represent lesser distortions across an array of symptomatology.
3. Severe defensiveness: The patient denies the existence of any psychological problems or symptoms. This categorical denial includes common foibles and minor emotional difficulties that most healthy individuals have experienced and would acknowledge.

Evidential certainty in this crucial area of deception is a complex and multi-layered issue. It is one of the most challenging aspects of forensic, judicial and clinical findings about deceptions can be best seen on the continuum: Definite unsupportive.
Degree of certainty is and illustrated in Fig VII below.

Fig VII Degree of Certainty in Findings (Rogers, 1997; Koch, 2016)
Level of certainty - Unsupported
Clinical criteria
Non-significant or conflicting research findings.
Speculative
Conclusions that are consistent with accepted theory and supported by one or two studies of limited generalizability.
Tentative
Research studies consistently show statistical significance in the expected direction, but have little or no practical value in classifying individuals.
Probable
Research studies consistently establish statistical significance in which cutting score, measures of central tendency, or a similar statistic accurately differentiate between at least 75% of the criterion groups.
Definite
Accurate classification of 90% or more of individual person based on extensive, cross-validated research. Findings are congruent with accepted theory.

As a counterpoint to the concept of certainty in deception detection, the ‘unanticipated questions approach’ (Sooniste et al, 2016) indicates that liars and truth tellers differ in their ability to answer unexpected questions during an interview i.e. liars competence in answering unanticipated questions is impaired as they, unlike truth tellers cannot rely on simple recall or on prepared answers, and hence appear inconsistent, and lacking in valid detail. This fascinating research illustrates a new wave of detection research and practice characterised by asking questions strategically in order to elicit cues to deception and truth.

Conclusion
Practitioners and post graduate students in forensic and clinical psychology all need to be cognizant of the multi factorial nature and complexity of deception detection (Myklebust et al, 2016; Kane & Dvoskin, 2011). Initial identification of one or more characteristics mentioned above need to be followed up and backed up by further evidence before a reliable assessment of deceptiveness in one or more contexts can be substantiated. As has been stated, there is no one ‘holy grail’ predictor of deception. Instead, the experienced forensic or clinical practitioner builds up an impression of congruence or incongruence of many communications and uses this as the basis and justification for opinions on deception. The use of fabrication, exaggeration or malingering is typically a matter for the courts to decide but they require expert assistance. Continuing professional development in this area includes awareness of research and communication skills training in detection deception, using role play discussion and written statement analysis.

Understanding micro-expressions in verbal, non-verbal, and written communications is the key – analysing its subtlety in the challenge for the criminal and civil justice systems, and police and security services, as they increase confidence and competence in investigative interviewing (Westra and Powell, 2016).

References
Koch HCH (2016) Legal Mind: Contemporary Issues in Psychological Injury & Law. Expert Witness Publications, Manchester.

Oxburgh G, Myklebust T, Grant T and Milne R (2016) Communication in Investigative and Legal Contexts. Wiley. London.

A full list of references can be obtained from the first author.

The authors regularly provide medico-legal reporting clinics in Cheltenham and London (Hugh Koch), Cambridge, Luton, Peterborough and Newmarket, Coventry, Leicester and Rugby (Katie Newns, Tom Boyd and Jill Peters) and can all be contacted via www.hughkochassociates.co.uk.

I am grateful for helpful comments from Professor Michael Brookes, Professor of Forensic Psychiatry. Birmingham City University.