Handbook of Psychology of Investigative Interviewing: Current Developments and Future Directions

by Ray Bull, Tim Valentine, Dr Tom Williamson

  instincts or intuitions should not be viewed as answers in and of themselves

  but as hypotheses to be tested via critical thinking. Once all the data have been

  collected and alternative hypotheses considered, decisions could be drawn

  based on the balance of probabilities (Herv é , Cooper & Yuille, 2008 ). That

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  is, a conclusion of whether someone is telling the truth or lying in a given situ-

  ation should be based on the balance of probabilities. Of course, the particular

  threshold for decision - making will largely be dictated by contextual factors,

  with lower cut - offs being used for screening purposes (e.g., individuals being

  screened for further evaluations, such as employees in airport security) and

  higher cut - offs being used for fi nal decisions (e.g., individuals being excluded

  from fl ying).

  In addition to promoting critical thought, we advocate that any decision -

  making model should be objective, fl uid and ethical. It should be standardized,

  yet fl exible enough to be tailored to individual cases, much akin to using

  structured clinical guidelines in the assessment of risk for recidivism and CBCA

  in the assessment of verbal content. Moreover, the approach should be trans-

  parent so that it can stand up to scrutiny by others – a criterion that is inher-

  ently met if the aforementioned criteria are also met. As with many types of

  assessments, as long as the recommendations and conclusions stem logically

  from the body of the report, the method in question should be relatively

  ‘ bullet - proof ’ . The same is true with the evaluation of truthfulness.

  Generalizing from the classroom to the real world

  Although unlearning bad habits, acquiring knowledge and skills, and using the

  right method for evaluating truthfulness are necessary to conducting such

  evaluations effectively, it is important to note that these steps are not suffi cient.

  Indeed, there is a growing body of research in the education literature that

  suggests that learning does not generally translate well to real - world settings

  without both practice and support (see Bransford, Brown & Cocking, 1999 ).

  With regard to practice, the old edict still, in part, applies: practice makes

  perfect! Practice becomes especially important when unlearning bad habits, as

  this involves fundamentally changing one

  ’ s beliefs about and approach to

  evaluating truthfulness. At the 2nd International Investigative Interviewing

  Conference (2006), one attendee highlighted that, at the very least, profes-

  sionals involved in conducting evaluations of truthfulness should learn about

  their own bad habits and how to counteract them (we agree fully with this

  proposition). The bottom line is that without focused practice, people simply

  tend to revert to old patterns, including bad habits (smoking being a case in

  point).

  Unfortunately, when it comes to evaluating truthfulness within professional

  settings, the amount and type of practice available to individuals are often

  constrained by environmental demands (e.g., from caseloads to outdated regu-

  lations). For example, while videotaping interviews can prove very valuable in

  terms of practice and conducting evaluations, many jurisdictions/organiza-

  tions still shy away from videotaping. Moreover, new approaches to evaluating

  truthfulness, particularly those akin to the one proposed in this chapter (see

  Evaluating Truthfulness

  319

  below), often require not only time to learn but more time than previous,

  outdated approaches. Indeed, there is no question that relying on instinct

  alone is much quicker than collecting high quantity and quality data, which is

  constantly evaluated via a hypothesis - testing approach. However, if accuracy

  and resistance to challenges/scrutiny are the objective, we suggest that the

  latter, more time - consuming approach should be employed.

  Given the additional demands associated with practicing new skills or

  methods in general and a specifi c approach to evaluating truthfulness in par-

  ticular, we strongly believe that the generalization of information from the

  classroom to the real world will depend not only on practice but also on the

  amount of support received by the sponsoring agency/supervisors. Ultimately,

  for training to be successful, trainees will need the support and guidance of

  those around them, including superiors. In addition to providing tangible

  support (e.g., smaller caseload; videotaping capabilities), having a supervisor

  who is knowledgeable and skilled in evaluating truthfulness allows for a men-

  toring approach to training, thereby ensuring that bad habits are replaced with

  evidence - based practices. This approach can also help protect against drift over

  time, that is, the re - emergence of old or emergence of new bad habits.

  An evidenced - based approach to detecting

  truth and lies

  Grounded in the research noted above, an approach to evaluating truthfulness

  was developed to blend empirical evidence with the experience of clinical -

  forensic mental health professionals and law enforcement professionals. The

  mix of science and practice produced an approach to evaluating truthfulness

  that is evidenced - based, user - friendly and ethical in nature. As can be seen in

  Figure 17.2 , this approach is rooted in the psychology of lying and truth -

  telling (see Figure 17.1 ).

  When a person tells a lie or the truth, it can lead to emotional and/or

  cognitive consequences that are leaked behaviourally (see Figure 17.2 ). That

  is, when a person tries to lie about an emotion or has an emotion about lying,

  that emotion will leak out (i.e., an observable change will occur). When

  someone lies about their thought process or is thinking about lying, that too

  will leak out. Although not commonly discussed in the deception literature,

  as noted above, truth - telling can also result in leakage. A person telling the

  truth, for example, may leak emotions that refl ect contextual factors (e.g.,

  anxiety about the consequences of telling the truth, such as returning to jail;

  fear of being disbelieved, as displayed by Desdemona in Othello ), the topic

  under discussion (e.g., during a murder investigation, an interviewee may

  display sadness or anger at the loss of a friend), and/or factors unrelated to

  either the topic or the context (e.g., during an investigation, an interviewee

  may display anger or sadness associated with the fi ght he or she had with his

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  Handbook of Psychology of Investigative Interviewing

  Truth / lie

  Emotion

  Cognition

  Leakage

  Change from baseline

  (within and/or across channels)

  Voice

  Face

  Observable

  channels

  Verbal style

  Body language

  Verbal content

  Hot spots

  Figure 17.2: Model for evaluating truthfulness

  or her partner that morning). Similarly, the truthful person may have parti-

  cular thoughts regarding the context or more unique views about the

  topic under discuss
ion. The bottom line is that someone can have emotio-

  nal and cognitive reactions when telling the truth, reactions that should not

  be confused with signs of deception. Consequently, it is extremely impor-

  tant to consider alternative hypotheses when conducting evaluations of

  truthfulness.

  When a lie or a truth affects or changes one ’ s psychological state, be it

  emotional or cognitive, there will be some consequence of this change: leakage.

  It has been demonstrated that lies can leak out through a variety of channels

  or aspects of behaviour. The channels depicted in Figure 17.2 were chosen for

  the present model for two reasons: (i) they have been found to be valid indica-

  tors of leakage (i.e., evidenced - based); and (ii) they are easily observable in

  interviews without the use of equipment/technology (i.e., are user - friendly),

  unlike, for example, techniques that measure physiological changes (e.g., heart

  rate).

  The easiest way to detect leakage is through a change in baseline (i.e., how

  the person typically behaves). That is, it is easier to detect leakage in what

  someone says if it is known how that person says things when not lying and/

  or infl uenced by factors known to affect their psychological states when telling

  the truth (see above). Similarly, it is easier to detect a leak through body lan-

  guage if you have some knowledge of the baseline body language of the

  person. At times, collecting such baseline information might reveal a ‘ tell ’ (the

  Evaluating Truthfulness

  321

  term ‘ tell ’ is used by poker players to refer to a behaviour that gives away, or

  ‘ tells ’ , that a player has a good hand or is bluffi ng). Note that this is not a

  ‘ universal ’ sign but a sign that applies ‘ only ’ to the individual in question and

  likely inconsistently, that is, it is a person - specifi c leakage that the person typi-

  cally displays when lying. Baseline information is also crucial in evaluating how

  a person typically responds when telling the truth, which can then be con-

  trasted with their reactions when lying.

  It is important not to assume automatically that the identifi ed leakage is a

  sign of deception. Indeed, leakage, be it emotional or cognitive, can refl ect

  lying or truth - telling. Accordingly, we urge people to adopt a new term when

  observing leakage: a ‘ hot spot ’ . A hot spot is any signifi cant change in a per-

  son ’ s baseline behaviour within or across one or more observable channels.

  Inconsistencies between channels are particularly signifi cant hot spots, such as

  when the person says, ‘ No, I didn ’ t do it ’ all the while nodding ‘ yes ’ . Clearly,

  when one

  ’ s nonverbal behaviour perhaps unconsciously contradicts one

  ’ s

  verbal content, evaluators can – at the very least – be confi dent that the topic

  under discussion is creating internal/psychological confl ict for the interviewee

  and, therefore, should be followed up. It is theoretically appealing that such

  inconsistencies are especially meaningful and more likely to be associated with

  lying than with truth - telling. Indeed, not only is truth - telling likely to lead

  effortlessly to the coordination of channels in such a manner as to lead to

  consistency across channels, the monitoring and coordination of multiple

  channels is inherently harder for liars to achieve than the monitoring and

  controlling of only one channel. This phenomenon is akin to juggling: it is

  simply easier to juggle one or two items than four or fi ve. Unfortunately, the

  same can be said of evaluators. That is, it is harder to learn to monitor multiple

  channels in others than only one or two, again highlighting the importance

  of training and practice in active listening and observing across multiple behav-

  ioural channels.

  The bottom line is that, when a change occurs in, or there is an inconsis-

  tency across, a person ’ s face, body language or voice pitch, this is meaningful:

  change and/or inconsistencies do not occur randomly. Again, a hot spot is

  not a clue to lying; rather, it is a clue to importance. A hot spot may occur

  for a variety of reasons, of which lying is only one possibility (others include

  thinking about something off - topic, truth - telling). This highlights the impor-

  tance of knowing about the nature of truths and lies and using a hypothesis -

  testing approach to evaluating truthfulness.

  Step - wise approach to evaluating truthfulness

  Although the model outlined in Figure 17.2 and described above provides

  the foundation from which to gain knowledge and acquire skills specifi c to

  evaluating truthfulness, it does not provide a method for implementation. We

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  Handbook of Psychology of Investigative Interviewing

  therefore suggest the following step - wise approach to evaluating truthfulness

  in clinical - forensic practice:

  Seek background information

  If possible, the evaluator/investigator should prepare for the interview/inter-

  action by collecting background information. This will help defi ne and identify

  the central issues, as well as other topics of interest. Evaluating truthfulness is

  akin to conducting other types of assessments in clinical - forensic contexts:

  professionals should never enter such contexts with patients/client/offenders

  blindly (i.e., before reading institutional/case fi les or discussing the case with

  the referral source). The more information that is attained, the better position

  the professional will be in to evaluate the interviewee. It is crucial that inter-

  viewers review as much information as possible before interviews, as this will

  help them develop interview strategies, will facilitate their ability to develop

  alternative hypotheses and will help them better evaluate the baseline of the

  interviewee. For example, at the time of the interview, interviewers can ask

  questions about known topics, which will allow them not only to collect base-

  line information (how the person behaves when telling the truth and/or lying),

  but to begin to develop an idea of the response style the interviewee is adopt-

  ing (e.g., positive vs. negative impression management). Of note, if the inter-

  viewee is from another culture, background information on culture - specifi c

  topics related to the issue at hand (e.g., attitude to crime, mental health, busi-

  ness process and organizational structure), expected social conduct (e.g., social

  hierarchy and related interpersonal expectations, shameful behaviour) and

  behavioural idiosyncrasies (e.g., body language, eye contact, emotional expres-

  sion) should be collected. Such information will prove crucial in assisting

  evaluators to avoid culturally - based idiosyncratic errors.

  Establish baseline

  The more baseline information obtained, the better position the evaluator will

  be in to detect changes from baseline. Again, by baseline we are referring to

  how someone typically behaves under certain conditions (e.g., when telling

  the truth, when lying; when happy, when sad). When using our model, or any

  other behaviourally

  - based model, we suggest that evaluators seek baseline

  information
about all fi ve channels depicted above (see Figure 17.2 ) − from

  facial expressions, eye contact, eye movement, gestures, voice characteristics,

  and verbal style and content. The establishment of a baseline can be made by

  discussing the person with others (e.g., case managers, front - line staff), through

  recordings of the person or in face

  - to - face conversation. If using the last

  approach, the collection of baseline data can easily be accomplished during the

  rapport - building phase of the interview. It is important to note that the rapport

  phase should also focus on making interviewees relatively at ease, as this serves

  Evaluating Truthfulness

  323

  to decrease anxiety stemming from issues unrelated to the topic at hand that

  too often result in hot spots unrelated to deceit. In essence, the goal is to cali-

  brate the situation (i.e., relax the interviewee) in such a way as to decrease the

  noise - to - signal ratio (topic - unrelated hot spots/topic - specifi c hot spots), not

  unlike that accomplished by polygraphers during their rapport - building phase

  of the pre - polygraph interview.

  Observe hot spots

  With baseline information in hand, the interviewer should actively observe and

  listen in order to be alert for changes within a channel or inconsistencies across

  channels, as well as for any signs that suggest the person is being truthful. To

  facilitate active listening and observing, it would be wise to remove any poten-

  tial distracters such as those that are psychological (e.g., unresolved issues

  about the case, context or personal topic), physical (e.g., fatigue and/or

  hunger) and/or environmental (e.g., noise and/or visual barriers) in nature.

  Any signifi cant change from baseline is a hot spot and the topic that produced

  the change should be noted. The hot spot should be used to determine if

  the observed change was due to emotional or cognitive reasons. If possible,

  the topic should be raised later to see if it again produces a similar hot spot.

  If the hot spot occurs consistently, one can be relatively confi dent that it was

  produced by the topic under discussion, as opposed to some unrelated issue.

  Evaluate alternative hypotheses

  As discussed above, knowing that a particular topic consistently gives rise to

  a hot spot only provides information indicating that a topic of importance has