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"Better that ten guilty persons escape than that one innocent suffer.." (Sir William Blackstone, 1765)


By C. Gerald Carter

(*American Polygraph Association Magazine, Mar/Apr 2016, Vol 49, 2, Page 69)

Problem statement

This paper addresses the question of whether a professional polygraph association – state, national or global – should establish policies or guidelines related to court testimony by members regarding polygraph exams administered by other examiners.

I have been conducting polygraph examinations as a private examiner since 1980, during which time I have encountered my share of controversial issues. None of these issues had much of an impact on me personally until a recent challenge arising around my testimony in April, 2014 as a polygraph expert in a capital murder trial. It started when two defense attorneys asked me to review a polygraph exam administered to their client by a police examiner.

In summary, my testimony was that the examination did not comply with a number of standard practices promoted in the profession as of January 1, 2009.1 I further provided documentation to support my assertions. I expected a rebuttal witness or witnesses based on the fact that the prosecution had two polygraph examiners observing in the courtroom, one of whom was a member of the state polygraph board. The prosecution did not call any rebuttal witnesses to my knowledge.

Ironically, it was not the testimony I presented in the case that generated the controversy. The objection was stated in a meeting of our state polygraph association one month later proposing adoption of a new policy to define testimony by one member “against” another member as an ethical violation. Is this attitude current among members of the profession beyond my state?

Recently I attended a polygraph workshop sponsored by another state association which reinforced my new concern regarding ethical standards within our profession. During the course of his presentation the instructor admitted to having firsthand knowledge of a polygraph examiner in his department who intentionally falsified the results of a polygraph exam. According to the instructor, this examiner admitted to him personally that he falsified the results on a rape suspect in order to show deception on the test. The instructor told the audience made up of experienced examiners that he did not report the violation.

How many other tests has that examiner falsified and what impact might those actions have imposed on defendant verdicts? Why did this instructor, a professional examiner and role model for examiners, choose not to report a deliberate falsification of polygraph results? Why was he comfortable and unapologetic when relating his story to a room full of examiners? This anecdote implies a lack of accountability within our profession that should cause us all concern.

The same instructor later asked for a show of hands of anyone who had critiqued another examiner’s work product in court. My hand was the only one raised. I held my own with the instructor, but I was caught off-guard, and I felt uncomfortable having to defend my ethical choices in contrast to those he seemed to be promoting in his presentation.

The concept of a profession implies that all practitioneers deliver services that meet minimum quality standards or better. On that basis we should all administer exams that can hold up under quality review. We should welcome, not oppose, such oversight so long as it is delivered in a fair and impartial manner.

How prevalent are efforts to discourage examiners from performing quality reviews of work products provided by other examiners and contesting those in court? Such efforts may be formal, as in the resolution proposed to our state association, or informal, as in the training session referenced above. If judges become more inclined to allow polygraph evidence in court, will it be credible? Who will be willing to review and assess the quality of exams, and with what impact to his or her professional status?

I believe this issue needs to be examined and discussed openly within our professional associations. In order for examiners to work as a profession under one umbrella, law enforcement and private examiners alike, our professional associations must openly support the integrity of our work product over solidarity among examiners. Only through a commitment to quality can we successfully arbitrate legitimate issues that arise regarding the practice.

Case Study of a Controversy


One month following the trial mentioned above, our state association convened its regular quarterly meeting. My testimony in that trial was that, in my opinion, a specific polygraph exam deviated from recommended practice. I expected my testimony would be an item for discussion. It was not listed as an item on the meeting agenda, but I wanted to participate in any discussion that was open to the membership.

On the day of the meeting I arrived early and was confronted by a long-standing member of the association board. He knew about the case but was not interested in any details from my perspective. He indicated that the content of or basis for my testimony was not important. What was important, to him, was the fact that I testified “against” another member. He further stated that he had reviewed the charts in question and that his analysis was that there was nothing wrong with the charts. He was not interested in what I found regarding the examination process that established the basis for my court testimony.2

Midway through the association meeting, this same board member proposed a new policy that would define testimony by one member of the association “against” another member of the association as an ethics violation. Put another way, the work of no member of the association could be challenged in court by another member of the association without the challenger being labeled professionally unethical.

He further requested that the president appoint a committee to draft the policy for consideration by the membership at a later date. He mentioned that “one member” had recently testified in opposition to an examination administered by another member and he thought the association should address it in this way. He made no mention of the details of the case in question or the testimony. The president did appoint a committee at that meeting, but, as of submission of this paper, I have no official knowledge whether or not the association has taken any action.

To date I have found no other polygraph association that has a formal resolution defining court testimony in which one member questions procedures or outcomes of a polygraph exam administered by another member as an ethical violation under association policy. If my state association adopts such a resolution I believe it will be the first.


In order to support meaningful discussion of this controversy, I need to provide an overview of the case and testimony. No one outside of the courtroom has ever asked to see my testimony, before or after the proposal of a new policy. I believe that the facts of this case, along with my testimony, provide clear demonstration of the obligation for peer review when polygraph related evidence is admitted into court proceedings, criminal or civil. I hope this narrative also points to a possible way forward.


The following points are based on an audio-video recording of the polygraph examination and separate documentation of the examiner’s pretest notes, both of which were made available to the defense.

The jury found the defendant not guilty of capital murder but guilty of lesser charges. He was sentenced to serve 22 years in prison. The defendant appealed alleging that the polygraph examiner used interrogation tactics in the pretest. As of publication, this appeal is working its way through the court system.

Polygraph Testimony

Both of the defendant's attorneys were court appointed. With approval from the judge, they employed me to provide a quality control review of the polygraph examination. After reviewing the polygraph evidence, I decided to go beyond my polygraph experience and document whether the chart tracings were produced by best practice standards prevalent on January 1, 2009.

In my testimony, I concentrated on three main areas for review of the polygraph evidence. These were:

  1. Wording of relevant questions – major issue;

  2. Physical and mental health of examinee; suitability as test subject – major issue; and

  3. The length of the pretest - issue.

I further committed to research and documented my testimony with articles from prominent researchers in the polygraph field.4

  1. Wording of Relevant Questions

During the actual polygraph examination, relevant questions 1 and 2 were asked as follows:

    1. Did you intentionally shake A… several times?

    2. Did you intentionally shake A… several times while at your trailer last Friday?

During the pretest interview, the defendant never stated that he shook his daughter. The polygraph question is assuming that the defendant did shake his daughter. In this case scenario, “intentionally” is a state of mind and a non-testable item.

Furthermore, a written report submitted by the police examiner on January 2, 2009 listed the relevant questions asked during the examination administered to the defendant on January 1, 2009 as follows:

  1. Did you shake A… several times?

  2. Did you shake A… several times at your trailer last Friday?

Had the examiner used the original wording for the relevant questions he could have avoided the potential distortion created by the word “intentionally.”

  1. Physical and mental health of examinee; suitability as a test subject

In the medical history, obtained and documented by the police examiner and provided to the defense, the defendant provided the following information:

The examiner had enough information about the medical and mental history of the defendant to question whether he was a good candidate for a polygraph examination at that time. Given the defendant’s lack of sleep and food, and deprivation of medications, I would have rescheduled this subject for another day when those requirements had been met. No compelling reason was presented in court to test the defendant under the circumstances described.5

  1. Length of Pre Test

By my calculations, the length of the pre test was 3 hours and 12 minutes. Even though I could find no documentation on pretest time limits, the information needed to conduct a professional polygraph examination is normally obtained in a much shorter period of time. The trial Judge appeared to agree when he instructed jurors not to consider the alleged results of the defendant’s polygraph when determining whether he was guilty, only the role the hours-long polygraph process played in the statements he made to investigators.6

Analysis: Why did this testimony create controversy?

Our professional associations have yet to define a common ethical code of conduct by which all members are obligated to comply; consequently, there is no single set of ethical requirements or assumptions under which we conduct polygraph exams.

This case study demonstrates that the author’s common sense definition of a polygraph examination as “an effort to identify the truth regarding specific details related to a specific event or events through use of the polygraph instrument as a tool,” which seems self-evident, is not universally accepted among licensed polygraph examiners and members of our professional associations. In this case, when measured against loyalty toward another individual member of the association, loyalty trumped truth on the balance scale for some members and leaders.

I found an interesting theory by German political scientist Elisabeth Noelle-Neumann that suggests an explanation. 7

The relevance of Dr. Noelle-Neumann’s theory for this case study depends on the fact that there are more than one distinct sub-groups included under the umbrella of “licensed polygraph examiners.” The first and largest sub-group of polygraph examiners consists of employees of law enforcement agencies, whether federal, state or local. The second consists of private examiners. Neither group is monolithic, but one characteristic of some private examiners creates a possible third or hybrid group. It includes examiners who work for both law enforcement, i.e. the prosecution side of the criminal justice system, and for defense lawyers. My practice falls within this hybrid definition and, I believe, allows me to offer a helpful perspective.

Dr. Noelle-Neumann refers to her theory as the Spiral of Silence8which stipulates that individuals have a fear of isolation resulting from the fear that a social group or the society in general might isolate, neglect, or exclude members due to the members' opinions. This fear of isolation consequently leads to remaining silent instead of voicing opinions. Dr. Neumann (1974) introduced the “spiral of silence” as an attempt to explain in part how public opinion is formed.

The phrase "spiral of silence" actually refers to how people tend to remain silent when they feel that their views are in the minority. The model is based on three premises:

The closer a person believes the opinion held is similar to the prevailing public opinion, the more they are willing to openly disclose that opinion in public. Then, if public sentiment changes, the person will recognize that the opinion is less in favor and will be less willing to express that opinion publicly. As the perceived distance between public opinion and a person's personal opinion grows, the more unlikely the person is to express their opinion.

My state association is made up of 80% or more of police examiners. There are approximately 8 to 10 private examiners.9 In the quarterly meeting of my state association described above, only one member defended my actions in testifying against another examiner and he was one of that small group of private examiners. The other members either remained silent in the meeting or expressed whatever views they held outside of the meeting. Ironically, I also remained silent, further reinforcing Dr. Noelle-Neumann’s theory.

The “spiral of silence” theory provides one explanation for this behavior, but the ethical foundation for adopting the equivalent of a gag order as policy is flimsy.


I believe that identifying a problem implies a responsibility to propose one or more optional solutions. In that spirit, I suggest that the American Polygraph Association should consider developing a comprehensive professional code of conduct for advice and consent by its membership and, once adopted, should require all existing and new members to sign a compliance commitment.

As a first step toward increasing accountability, I believe that the issue of examiner testimony should be addressed as an ethical consideration requiring immediate attention, in advance of work on the more comprehensive code.

At a minimum I propose that the APA adopt guidelines for conducting quality reviews of polygraph exams for court proceedings. My recommendations below are offered as a starting place for these conversations.


If called upon to testify again in a similar situation, would I do it? My answer is an unequivocal yes. It was the right thing to do. Every person accused of a crime deserves a most vigorous defense. Since 1989, 1620 people have been exonerated from their wrongful convictions according to the National Registry of Exonerations, a joint project of the University of Michigan and Northwestern University law schools. Verdicts based on “truth beyond a reasonable doubt” were proven false.

I am a better polygraph examiner and a better person for having testified as a polygraph expert. As examiners, we must always adhere to the concept that we are seekers of the truth – not interrogators! Every individual who walks into our polygraph suite is dependent on us to conduct a fair, objective and technically competent exam. Honoring their trust is our obligation and must always be our goal.

Because of the rarity of polygraph evidence being introduced in court, I do not expect to be called to testify again, whether for the defense or the prosecution. I believe, however, that it is the right and duty of any polygraph examiner to testify if the circumstances warrant. I chose not to fight the proposal in my state association. Rather I resigned my long standing membership in favor of resuming active membership in the American Polygraph Association where I have found more acceptance of open discussion and diverse ideas.

This decision was difficult for me but I found support from an unexpected source. A new Episcopal priest at the church I attend reserves the first few minutes of the service to make announcements. One Sunday, during the height of this controversy, he walked in and read the following quote: “Seek the truth, come whence it may, cost what it will.”10 He gave the name of the author and started the service. His sermon was not related to the quote. I was amazed by the implications that quote had for my situation.

That quote exemplifies the purpose of a polygraph examination. We are “Seekers of the Truth.”11 We owe that level of objectivity to every person who walks into our polygraph suite. If I am such a seeker, I have to be willing to pay the cost.

If possible, I would like to see our associations begin to clarify whether the polygraph profession defines itself as primarily a “band of brothers” or as committed “seekers of the truth.” Perhaps we can become both by defining a common ethical code to which we all commit and by which we can hold ourselves accountable. 12

1 This was the date of the polygraph examination administered to the defendant.

2 In a recent news article, information was revealed that Justice Scalia and Justice Ginsburg were “best buddies.” They rarely found themselves on the same side of controversial issues. Hopefully, this teaches us the important lesson that we should disagree with ideas, not people.

3 Burkett, Seith. "Shaken Baby Defendant Guilty of Manslaughter." Decatur Daily, Friday, May 2, 2014.

4 Court testimony notes and various articles are available to the reader upon request.

5 January 1, 2009 was a Thursday. According to the defense, the defendant was to be given a court appointed attorney on Monday, January 5, 2009.

6 Burkett, Seith. "Shaken Baby Defendant Guilty of Manslaughter." Decatur Daily, Friday, May 2, 2014.

7 Elisabeth Noelle-Neumann (19 December 1916 – 25 March 2010) was a German political scientist. Her most famous contribution is the model of the spiral of silence, detailed in The Spiral of Silence : Public Opinion – Our Social Skin. The model is an explanation of how perceived public opinion can influence individual opinions or actions.

8 Noelle-Neumann, E. (1991). The theory of public opinion: The concept of the Spiral of Silence. In J. A. Anderson (Ed.), Communication Yearbook 14, 256-287. Newbury Park, CA: Sage.

9 According to information received from the American Polygraph Association on February 18, 2016, there are 32 APA members from my state, to wit: 23 members are police examiners and 9 members are private examiners.

10William Sparrow (Mar. 12, 1801-Jan. 17, 1874) was a leading evangelical theologian of this time. In 1841 he moved to the Virginia Theological Seminary, where he taught for the rest of his life. His primary areas of teaching were church history, theology, and Christian evidences. He served also for a while as dean. He is known for the advice he gave his students, "Seek the truth; come whence it may, cost what it will." Sparrow died in Alexandria, Virginia.

11 APA “Dedicated to Truth”; “NPA Truth Seekers”

12 Special thanks to Mr. Darryl Starks for taking the time to review an earlier draft of this article.

"Special thanks to Mary Lee Carter for her tireless efforts in editing this article".



A Technique to Increase Examiner Effectiveness

By C. Gerald Carter

                                                                                                         (*American Polygraph Association Magazine, Jan/Feb 2016, Vol 49, 1, Page 71)


The November-December edition of the APA Magazine [2015, 48(6)] includes a message from President Walt Goodson in which he emphasizes his commitment to expanding the diversity of training for polygraph examiners. Specifically, he states: “The intent of this expanded curriculum is to improve our work products by focusing on the one aspect of a polygraph examination we too often forget – the polygraph examiner.” He further clarifies that “. . . we can offer endless lectures regarding how to make the polygraph more scientifically valid; however, none of that matters when we don’t feel good, and we make human errors.”

As a private examiner with over 30 years of experience working with law enforcement agencies, prosecutors and defense attorneys, President Goodson’s remarks spoke directly to me. A basic understanding of one's self and that of the examinee are critical components in conducting a polygraph examination. We all have our own perceptions based on our experiences that influence our behavior. Understanding our own perceptions does not require us to change our views but does allow us to not be influenced by them. A basic understanding of personality differences reduces examiner stress and will give an examiner the ability to create objectivity and focus on the examinee. This understanding translates into being able to predict behavior of others and myself in a given situation, exercise emotional control in a given situation, better understand my own personality and consciously move my behavioral preferences in a given situation.

Personal stress drains energy and can undermine the quality of work. As examiners we are obligated to protect quality, reduce errors and achieve reliable results. Generalized stress is a distraction. We need to reduce it so we can use the full force of our energy to obtain accurate results. As “Seekers of the Truth,” the subject in our polygraph suite deserves our full and undivided attention!


What is it, and how do you do it?

Personality/behavior typing is built on the scientific finding that apparently random behavior is not really random at all. It is fairly orderly and consistent if observed over a period of time with the help of an accurate analytical theory or tool.

I began using personality based interviewing during the mid-1990s as a means of establishing rapport with a subject, improving the reliability of exams, and eliminating unnecessary stress. The experiences and practical examples relayed in this article are based on the application of insights derived from the work of Isabel Myers and Katharine Briggs as expressed through the tool they developed, the Myers Briggs Personality Type Indicator1 (MBTI).

With training and experience in personality based interviewing you can learn to observe behavior patterns as you first walk into an initial interview, whether it is in your office or in the field. You can also see patterns emerging that reflects the subject's preferences for the following:

As you learn more, you will begin to recognize each of the preferences in four bi-polar scales through both verbal and nonverbal cues:

To validate the subject's personality type and initiate rapport, make statements to the subject about what you have observed followed by questions whereby the subject can validate or contradict those observations. This allows the interviewer to continue observing behavior and to adjust his own assessment. Total accuracy of the typing is not essential to establishing rapport because the exchange of questions and answers are all about the subject and play to his or her own sense of identity and desire to be understood. I call this approach "advance and retreat" as it requires flexibility of both subject and interviewer.

The Advance and Retreat Interviewing Model

The advance and retreat model is a highly effective way to establish rapport with your subject. Inspiration for developing this technique came through reading about a horse trainer by the name of Monty Roberts2. Mr. Roberts gained fame by developing a method of communicating with horses using their natural body language and a technique he refers to as join up. Founded on a consistent set of principles, communication, and trust, Monty’s methods initiate a relationship; he never resorts to violence. You may be familiar with Monty Roberts name and work as it was the focus in THE HORSE WHISPERER, a Robert Redford movie.

I use my own version of an “Advance and Retreat” method in my interviews. When a subject first walks into my interview room, I accommodate his natural desire to withdraw or become defensive, a form of “retreat,” from what at the very least is an intimidating experience. After observing his behavior, I make an initial assessment of his preferences on the four scales referenced above: extrovert/introvert; sensing/intuition; thinking/feeling; and perception/judgment. Next I use what I know about these preferences to share predictions with the subject about his own behavior. The process is self-correcting, because the subject will either validate or deny my predictions, allowing me to make modifications until I get a clear fix on the personality of the individual I am dealing with.

The personality profiling process creates a natural curiosity resulting in the desire to know more or “advance” toward the interviewer. People like to talk about themselves when others show interest. At a gut level, people tend to interpret their personality as their identity, the essence of who they are. The interviewer who can create a connection with the subject based on an understanding of that subject's personality, connects with his sense of self. Subjects recognize the understanding demonstrated by the interview as rapport and becomes more responsive and less defensive. The interviewer learns to interpret the subject’s communication more accurately because he is able to move into harmony with what the subject is trying to communicate and not just the words.

Typing based on behavior observation and verbal interaction can be effective without relying on validated paper and pencil or electronic tools. The primary benefit is that this approach, when skillfully implemented, leads to highly accurate assessments and behavioral predictions much of the time. Consider the following polygraph which I conducted for a private attorney in the same area where, at that time, I was conducting polygraph examinations for all of the local law enforcement agencies. The pretest consent form included the statement that I conduct polygraph examinations for the law enforcement agency that is investigating the attorney's client. The client signed the consent form acknowledgment.

During the test, I determined that the subject was using countermeasures. I confronted him and he acknowledged that he was just nervous. Due to the obvious countermeasures, I terminated the test. Later, this client took a polygraph examination with a different examiner and the results were reported as no deception indicated. I received a telephone call from the subject demanding to know who I had talked to in the District Attorney's Office. He stated that the DA was still actively pursuing his case. His reasoning was that I knew so much about him, i.e. his personality, that I could have only learned that by talking with someone in the system who knew him, implying further that I probably talked with that same individual following his test. The fact that none of this happened had no impact on his assumption that I had “talked with someone” as it was for him the only logical explanation.


This technique begins with establishing rapport in the pretest phase of administering a polygraph exam. This part of the testing procedure will ultimately set the tone and tenor for the entire process. The literature on pre-polygraph interviews collectively emphasizes the importance of establishing rapport but provides no clear consensus on how to do it. Personality based interviewing allows you, as the interviewer, to establish rapport in the initial five to ten minutes of the interview while at the same time obtaining information helpful throughout the examination process.

People like to talk with others around whom they feel comfortable. This is human nature, and it is the principle upon which the personality-based interviewing technique is based. We tend to identify and feel comfortable with people we perceive as having personalities similar to our own. This is evident when one interviewer is particularly successful in getting confessions from suspects who seem to act a lot alike. In many cases, the interviewer will also exhibit some of those same behavior characteristics. Subject and interviewer may be the same or similar personality types.

Consider for example the following subject who preferred Feeling3 over Thinking4 when making decisions. This subject was a suspect in the theft of a deposit bag from a business. During the pretest, the first interviewer typed the suspect as one who makes decisions using the Feeling preference. He accused the suspect of stealing the deposit bag and walked out. He asked a second interviewer who had a similar preference for Feeling to continue the interview. Within five minutes, the suspect confessed to the second interviewer. This is a prime example of matching personality preferences of the subject and interviewer.

Understanding and recognizing the different personality types can help an interviewer establish rapport similar to that which evolves naturally among individuals with similar personalities. This happens because the interviewer can learn to communicate reliably on the subject's level using the “language” of that personality. This decreases a subject's defenses and increases his capacity and motivation to communicate.


An equally valuable benefit of establishing rapport through personality typing is that it helps to counteract preconceptions you may have carried into the interview. Experienced polygraph examiners know the importance of maintaining objectivity. Interested parties, whether colleagues or clients, sometimes share expectations and/or disappointment regarding results. This is uncomfortable and when anticipated can threaten your own objectivity. If the interviewer has already established an opinion of the subject prior to the interview, objectivity is difficult.

Prior events obviously carry some credibility, but events change. Consider for example, a case where a female reported that a male employee where she worked had tried to rape her. This particular female had filed an unfounded similar report before this incidence. Upon interviewing the suspect, however, he confessed to the attempted rape. It is important that preconceived ideas not be present in the interview room. It will take away from your ability to uncover the truth.

Normal” versus “Abnormal” Reaction: A Precautionary Note

Consider the example of a manager who was responsible for a stolen deposit bag. At the start of the interview, the manager began to cry. Is this normal behavior, or is it a sign of guilt? An interviewer who does not understand different personalities could possibly assume that the subject was crying because of guilt. The subject did not cry when reporting the theft. Crying under similar circumstances would be abnormal for the interviewer; therefore, he may assume, it is abnormal for the subject and a sign that he fears being caught. In this case, however, the interviewer needs to consider that crying might be normal and predictable behavior, under the circumstances, for individuals with personality preferences different from his own.

What we perceive as an abnormal reaction for ourselves may be a perfectly normal reaction for another. In this particular case, the subject expressed his identity and role in life through feelings, not logic. It was his personality dictating the response which had absolutely nothing to do with guilt or innocence.

The most effective interviewing is based on the subject's perspective on where he is and how he views his role in life, not the interviewer's. The foundation for this kind of interviewing begins when the interviewer establishes mutual respect as an individual with the subject. The extent and manner in which the interviewer can establish this foundation determines the quality of communication that follows. We only get one chance to make a good first impression.

To conduct a quality polygraph exam, the interviewer has to exhibit skills similar to those needed to ride a bicycle. Both wheels must be in balance. The bicycle analogy consists of two parts. The back wheel indicates technical skills. This is knowledge of the case, basic polygraph techniques, and knowledge of the law. The front wheel represents relationship skills, those needed to communicate with people.


The concept of using personality typing to interview subjects originated through long term use of the Myers Briggs Type Indicator (MBTI). The MBTI was developed by an American mother and daughter team, Katharine Briggs and Isabel Myers. The work of Myers and Briggs was started in the 1920's by Katharine Briggs. She was interested in human behavior and, through her observations and reading of biographies, developed an original way to describe it. Her theory was published in the New Republic magazine on December 26, 1926.

Together with her daughter, Isabel Myers, Briggs began to integrate her work with that of Carl Jung. In the 1940's, Myers created a paper-and-pencil inventory based on Jung's theory and her mother's observations. Part of her motivation was to help people discover more about themselves. She was also interested in helping the war effort by assisting managers place people in occupational roles most compatible with their preferences. It took Myers more than 20 years to fully develop the MBTI.

The MBTI provides a useful measure of personality by looking at eight personality preferences as described above, that all people use in different degrees. These eight preferences are organized into four bi-polar scales. When you take the MBTI, the four preferences that you identify as most like you (one from each scale) are combined into what is called a "type."

While the interviewing technique presented here is based on the Myers Briggs Type Indicator, it goes beyond the scope of the instrument by offering a practical approach to using the concepts and theory on which it is based without actually administering it. This approach allows interviewers to understand and effectively deal with human behavior in a variety of situations with predictability.

The concept of using personality typing when conducting interviews is not new to experienced interviewers. Many interviewers practice elements of the technique instinctively without being aware of the theory that supports it. Personality typing, using the concepts and principles which support the MBTI, goes far beyond this gut instinct or awareness. It allows the interviewer to identify categories or traits and to draw on his knowledge of how these traits interact to produce predictable behavior.

Using this technique will increase an interviewer's ability to obtain the truth. This technique is about communicating with subjects in the language that they understand best. The subject will identify with and feel rapport toward the interviewer. The truth is more likely to come out when the interviewer demonstrates understanding of the subject as an individual through understanding his personality. A case in point involved a polygraph examination that I administered to a suspect in the homicide of a thirteen-year-old juvenile. I informed the subject of his deceptive polygraph results His reply to me was that he liked me and wanted to explain how he thought the homicide occurred but stated that he did not do it. His explanation was exactly what the crime scene revealed. His testimony was admitted into evidence at his capitol murder trial and he was convicted of the homicide.


Are you energized by being around people or by an inner orientation toward ideas, concepts and abstractions? How do you take in information? Upon what kind of information do you base your decisions? What is your lifestyle or work orientation? These are preferences that all of us have and demonstrate in normal, everyday behavior. We use these preferences in the same way we use either our left hand or right hand as dominant. It is natural for right-handed people to use their right hand. Although one could learn, out of necessity, to use his opposite hand as dominant, it is easier to use the hand we are most comfortable using. The same is true of personality preferences. If you are quiet by nature, you will tend to limit conversation with people you do not know. Can you change that? Absolutely, if you have the awareness and motivation to do so. Proficient understanding of this technique allows one to intentionally change his behavior as the situation demands. To begin to build that understanding, let’s take a closer look at each of the four bi-polar scales identified by the MBTI.

Extraversion (E) and Introversion(I)

The first preference to be reviewed is the extraversion - introversion scale. This scale reflects whether an individual is energized by being around people and things or prefers to focus on concepts and ideas. Generally speaking, an Extravert usually shows some type of nonverbal expression while the opposite is true for an Introvert. In approaching an interview situation, it is best to go into it in an introverted mode which requires a lower tone of voice, short sentences and straight to the point. An interviewer can switch from the introverted mode to an extroverted mode as the situation requires, without turning off a subject. It is the opposite going in as an extrovert and later trying to switch to an introvert. Extraverted behavior can overwhelm or alienate an introvert, who may tend to withdraw and tune the extravert out. Once the subject has decided to turn you off, he is unlikely to change his mind and give you a second chance.

Extroverts and introverts have different approaches to the world. Extroverts are very verbal and actually think out loud. They are relaxed and confident with people; they like variety and action and are readily approachable by others. My experience indicates that most con artists are extraverts. In the case of armed robbers, my experience indicates that they are primarily introverts who usually have some type of dependence on alcohol and/or drugs. Drugs allow an introvert to become an extrovert. In an interview situation, extraverts use obvious nonverbal gestures and facial expressions. This preference group has a tendency to interrupt you, and, conversely, can and must be interrupted by the interviewer. If you don't interrupt, the extravert will control the interview through constant verbalizing. This is true in deceptive and non-deceptive subjects.

Subjects who are often trying to “beat the interview” will use the extraverted preference to maintain control in the interview and intimidate the interviewer. The best response here is for the interviewer to go into a modified introverted mode with the subject. This involves a quiet tone of voice, use of short sentences, and constant interruptions. This is a countermeasure to regain control of the interview. It is designed to throw the subject off balance.

Introverts are generally very quiet people. Their answers are usually given in a low tone of voice and short sentences. They engage in conversation when led by questions. The inability to maintain eye contact is typical of this preference and should not necessarily be viewed as evasive behavior. When being interviewed, an introvert likes to reflect before answering. Periods of silence are common with the introvert, and the interviewer should deliberately incorporate them. A few minutes alone to reflect is an effective technique for obtaining admissions from introverts. This technique has the opposite effect with extraverts. Periods of silence for extraverts allow them to build up resistance and regain composure.

It is important for the interviewer to always touch the subject physically by shaking hands. Tell the subject your name and extend your hand. The introvert's handshake will be with the arm extended below his waist and will quickly release your hand. The extrovert will extend his hand straight out and make contact with your hand until you let it go. An extravert will often use a “very” firm handshake as a control mechanism over you. At some point during the interview, I will always point this out to them.

Introverted subjects must be interviewed with caution. Based on my observations, cases involving employees shooting co-workers were probably committed by introverts. In pre-employment interviews, I can usually associate prior admissions of workplace violence with introverts. In my experience, terminations for insubordination, poor attitudes, fighting and arrests for domestic violence are also associated with introverts. This may be because introverts keep things inside until they explode. The advantage that they have is that they are very difficult to read.

Previously I mentioned a technique I refer to as advance and retreat. Interviewers can type subjects verbally by making statements and asking questions. While research indicates that 50 percent of the population prefer the extraverted mode, my experience indicates that the average subject I interview regarding a criminal matter is generally an introvert. Because introverts are harder to read, officers may refer them disproportionally for polygraph exams. This personality may confuse you especially if a suspect communicates easily. If this is the case, look for this personality type to use the Perceiving5 preference.

How do you, as the interviewer, determine which are true introverts and which are extraverts?

Initially, you advance by saying something like, “You appear to be a quiet person.” If they agree, you know you are dealing with an introvert. If they disagree, you retreat. It does not affect the interview situation if you are wrong initially. The key to this technique is to let the subject know you want to understand how they think and look at things and will not proceed with the interview until you do. Be aware that some subjects will try to fake it but experience with the MBTI limits this countermeasure.

The subject now has two things to deal with, the facts of the case and you. As you type a subject, he begins to realize that you can predict his behavior. When you start pointing out aspects of his nonverbal behavior, you are placing emphasis on this ability. Consider, for example, a subject that I interviewed who was leaning forward in his chair, obviously trying to intimidate me. When he decided to move back, I made the following statement to him: “I noticed that you moved back in your chair. You seem to be more relaxed now.” This demonstrated to that subject that I was alert to and could predict his behavior. From the subject's standpoint, he saw a stranger who seemed to understand him. This started the process of bringing that person into my area of influence. What normally happens at this point is that the subject begins to allow me to take control and direct the interview. Control and direction of the interview is what makes it possible to obtain significant admissions.

Sensing (S) and Intuition (N)

The next preference concerns two opposite ways of understanding one's surroundings: sensing and intuition. It deals with how we choose to obtain information and what kind of information we trust. Approximately 75 percent of the population prefers sensing, and most of the subjects you interview will use the sensing preference. People with a preference for sensing trust information that comes through the five senses: sight, hearing, taste, touch, and smell. Very few intuitives have ever been referred to me as suspects in a criminal investigation. Sensing subjects are very detail oriented, choose not to look down the road, and trust only what they have experienced. They communicate and should be addressed in the present tense. Consider for example a young high school suspect who confessed to being involved in the robbery and murder of a store clerk. After he confessed, his only concern was whether he would get to play college baseball. His present orientation and total lack of awareness of long term consequences was startling.

Intuitive types rely on possibilities, on what can happen and their “gut feeling.” Future possibilities are more real to the intuitive than the here and now. One key to recognizing a subject who prefers intuition is his use of the future tense, words ending in “ing”, and the presence of the word “possibilities.” The interviewer should approach witnesses with caution who prefer intuition over sensing. They are likely to make statements that they believe are true even though the action never really happened. This is part of the big picture that an intuitive see.

If the subject ever uses the term “possibilities,” you are probably dealing with an intuitive. One example of such a case involved a reported jewel theft from a female's apartment. The main suspect was the ex-boyfriend. He admitted the possibility that he could have taken the jewelry but had consumed so much alcohol that night, he wasn't sure. In our experience, an intuitive is unlikely to commit a crime for immediate gratification but rather for some future result or impact. In the case mentioned, the theft was designed to get even with the girlfriend. This subject agreed to replace the cost of the jewelry.

With a 75% probability of the subject using the Sensing preference, I use the following scenario: “I think that you are probably the type of person that remembers every good and bad thing that has ever happened to them. If someone ever lies or cheats you, I know that you are capable of forgiving them but you never forget.” This typing scenario works very well. A suspect that commits a crime has a high probability of being an S.

Thinking (T) and Feeling (F)

The next preference deals with how we make decisions: thinking or feeling. Thinking types value logic and facts and appear detached from feeling issues. Interviewers should always be organized in presenting the factual aspects of the case to a thinker. With consistent logic applied by the interviewer, a thinking subject will usually provide some, maybe small, but significant admissions. A case in point involved a man accused of sexually molesting a young boy. I was administering a polygraph examination to the subject in his attorney's office in an attempt to clear him of the accusations. During the posttest interview, he admitted that he was trying to “beat the test” he was paying for. He was a definite thinker and felt compelled to respond to the consistent facts of the case. This was not a confession, but it was the next best thing!

Subjects who prefer to base decisions on feeling are different from thinkers in that they like harmony, find it difficult to confront and readily show their emotions. It is important that an interviewer does not interpret an obvious show of emotions as a sure sign of deceptive behavior. The feeling subjects are usually very likable and have a general tendency to be passive.

The subject with a preference for feeling is liable to give a false confession when confronted by aggressive interviewers. They usually confess due to the guilt phenomenon present in all feelers. Because the feeling preference has a desire to promote harmony, they have a tendency to fixate blame on themselves as a first option and confess to preserve harmony.

One clear example of this was a suspect who had been indicted for the murder of his girlfriend’s infant son. This suspect had given a quasi-confession to interviewers, stating that he had smothered the baby to stop him from crying. When he was subsequently interviewed in jail by another interviewer, he recanted the confession. Both the prosecution and defense stipulated to polygraph results. When I interviewed the suspect, I profiled him as an introverted feeling type who had a propensity to please those in authority. A later psychological evaluation stated essentially the same thing. This subject was exonerated of all charges by a grand jury that had previously indicated him for capital murder. By the way, the polygraph results were NDI.

Admitting to something that we did not do may sound strange, but depending on the personality type, it is very possible. My experience indicates that those who make significant admissions during a personality based interview will not recant.

Most research indicates that approximately equal percentages of the population prefer thinking or feeling in making decisions. Crimes involving thinkers usually are robberies, burglaries and homicides. For feelers, crimes such as embezzlement and other indirect or non-confrontational offenses are more common. I suspect that false positive polygraph results are often associated with a Feeling subject due to the fact that they have difficulty separating the concept of feeling guilty and actually being guilty of the crime under investigation.

Judgment (J) and Perception (P)

Last is the preference relating to lifestyle and work orientation: judgment and perception. Subjects who have a preference for judgment tend to be decisive and purposeful. They will feel anxious until a decision has been made and closure obtained. The subject who uses the judging preference wants closure and is motivated to provide the necessary information to the interviewer to complete the task and close the issue. The individual with this preference will plan and calculate moves and the interviewer should remember to keep the interview organized and structured for these individuals. They often appear early for your interview and most always, have some type of time piece close to hand. A good question to determine this preference is to ask the subject what would they do if their time piece was taken away. The J will respond by saying that they would be lost while the P could care less.

Subjects who have a preference for perception are spontaneous and curious. They sometimes feel anxious when they have to make a decision because they don't want to close off their options when something better might turn up! My experience indicates that Perception along with Introversion are the primary preferences for armed robbery suspects. Subjects with a preference for perception are very difficult to interview because they can switch subjects in midstream. This is a definite countermeasure to distract the interviewer. Interviewers need to be prepared to spend a lot of time with these kinds of suspects because they will generally give information in bits and pieces. If I find a suspect trying to change subjects, I will verbally instruct him to focus on the issue at hand. This is a direct use of the typing technique.

The following is a good example of the differences in how crimes are committed by a Judging versus Perceiving preference. A deposit bag is accidentally left on the unlocked manager's desk. Obviously this a crime of opportunity. By the time a J completes his plan to steal the money, a P would already have taken it. This is a good way to formulate suspects based on a lifestyle analysis of a crime.


The personality preferences that have been described will be exhibited by subjects you interview at one time or another. By recognizing and focusing on each preference in an individual subject, you can recognize behavior patterns projecting themselves and base your interview on a systematic technique as opposed to a gut feeling. You can navigate by a road map in a consistent manner. Knowing a direction the interview will take is a major stress reducer for an interviewer.

Begin to type the subject as soon as he walks into the interview room, but be aware that his behavior may change as he begins to relax. Even though you typed the subject's behavior initially, be prepared to type him again if necessary. He is more likely to exhibit his true preferences after he adjusts to the interview and becomes more comfortable with you as the interviewer.

After typing the subject, observe him for nonverbal changes in behavior and ask him about them as they occur. This demonstrates your explicit interest in the subject, and it will further build a connection or type of bond of understanding with the subject. Once the subject trusts that bond, quality information is likely to follow.


The systematic personality/behavior typing approach presented in this article provides a technique or template that interviewers can use in interviewing victims, witnesses and suspects. I like the comic’s page character Dennis' statement: I color outside the lines because there's more room. Similarly, using this approach expands insight into the subject and reveals new options available to you as an interviewer.

If you are using an interviewing technique now with which you feel comfortable, stick with it. Personality-based interviewing is not designed to replace your technique but to enhance it. The personality/behavior typing approach to interviewing enhances your traditional routine because it allows you to create a distinct relationship with the subject in the first few minutes of the interview. The stress you reduce on yourself, the interviewer, you increase and target toward the subject.

To use this technique most effectively, take your time. Don't try to interview when you are not in the right frame of mind. You know when you have reached that point. Interviewers who elect to use the personality/behavior typing technique will find that, as they begin to understand different personality types, they will also acquire greater understanding of their own personality preferences. With that understanding comes greater self-control and effectiveness in all contacts, personal and professional. The inherent stresses of interviewing will recede to a more manageable level. Once you learn how to use this technique, your new skills will allow you to readily adapt to any type of interviewing situation. As you master the technique, you will walk into any interview with increased self-confidence, knowing that you have the ability to understand the subject sitting before you.

That is the complete personality typing technique - a guided approach to interviewing. You will find that your ability to get subjects to reveal things will increase, not because you coerced them but because you influenced them to want to communicate. As a consequence, they will tell you more. That, of course, is always your goal - to secure truthful and relevant information about the case under investigation and obtain accurate polygraph results.


Briggs Myers, Isabel with Kirby, Linda K. and Myers, Katharine D. Introduction to Type, 6th ed. Palo Alto, CA: Consulting Psychologists Press, 1998.

Hirsh, Kandra Krebs, and Kummerow, Jean M. Introduction to Type in Organizations, 3rd ed. Palo Alto, CA: Consulting Psychologists Press, 1998.

Keirsey, David, and Bates, Marilyn. Please Understand Me. 5th ed. Del Mar, CA: Prometheus Nemesis Book Company, 1984.

Kummerow, Jean M., Barger, Nancy J. and Kirby, Linda K. Work Types. New York, NY: Time Warner Company, 1997.

Kiersey, David. Portraits of Temperament. Prometheus Nemesis Book Company, 1987.

1 There are many tools available for analyzing personality. The best grow out of and derive legitimacy from the same original research that informs the MBTI, i.e. that of Carl Jung. Because the concepts providing the building blocks of the MBTI are logical, flexible, easily communicated and understood, this author uses these structures to assess personality rather than a professional instrument. Such a tool would be intimidating; eye contact is compelling.

2See Mr. Roberts’ web site for more information at www.montyroberts.com

3 Preference for organizing and structuring information to decide in a personal, value-oriented way.

4 Preference for organizing and structuring information to decide in a logical, objective way.

5 Perceiving is defined as a preference for living a spontaneous and flexible life.


Giants and Shadows of Giants

The Possible, the Plausible, and the Probable

6/29/2014 Gerald W. Carter

Key thoughts:

                                                                                                                                       C. Gerald (Jerry) Carter



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