People like to talk with others around whom they feel most 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 who have personalities similar to our own. This is evident when one investigator is particularly successful in getting confessions from suspects who seem to act a lot alike. In most cases, the investigator will also exhibit some of those same behavior characteristics. Subjects and interviewer may be the same or similar personality types. Consider for example a suspect who preferred feeling over thinking when making decisions. This subject was a suspect in a crime involving the theft of a deposit bag from a restaurant. I initially typed the suspect but then called in a second investigator, who also had a preference for feeling, and asked him to continue the interview. I accused the suspect of stealing the deposit bag and walked out. Within five minutes, the suspect confessed to the second investigator. This is a prime example of matching personality preferences of the subject and interviewer.

What about those subjects whose personalities are not like ours? Knowing the different personalities can help an interviewer communicate on the subject's level and, thereby, increase the subject’s confidence in him. The level of communication that is established will help the interviewer conduct an effective interview. Equally important, as interviewers develop greater understanding of diverse personalities, they will learn to adapt more effectively to the varied situations that confront all investigators.

All behavior is communication. The way a subject sees himself and others unconsciously affects his choice of words and gestures as well as facial expressions and the manner in which he puts words and phrases together. We can determine a lot about any individual's perceptions of his own identity and role in life through the behavior he uses to communicate.

Consider, for example, 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 investigator 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 investigator; therefore, he may assume, it is abnormal for the subject and a sign that he fears being caught. In this case, however, the investigator needs to consider that crying might be normal and predictable behavior, under the circumstances, for individuals with personality preferences different from the investigator's.

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 begins with the subject's perspective on where he is and how he views his role in life, not the investigator's. The foundation for this kind of interviewing begins when the investigator 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. As always, we only get one chance to make a first impression.

To establish effective communications with a subject, the interviewer has to exhibit skills similar to those needed to ride a bicycle, i.e. both wheels must be in balance. The bicycle analogy consists of two parts. The back wheel indicates task skills. This is knowledge of the case, basic investigative techniques and knowledge of the law. The front wheel represents relationship skills, those needed to communicate with people on and off the job.

It does not matter what your personality preferences are. That is not the issue here. What is important is that you are able to adopt non-preferred behavior as the interview situation requires. We have all heard about the importance of first impressions, and that is critical in this first meeting. As closely as you are observing the subject, he also is observing you.

Focusing on the subject's personality preferences allows the investigator to increase his objectivity and intensify the level of communication in the interview. This provides some protection against bias. 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.

As you learn more about personality-based interviewing, you will begin to recognize each of the preferences in four bi-polar scales . You will do this through observing a combination of verbal and nonverbal cues. To arrive at the subject’s personality type and to start the bonding process, I recommend making statements to the subject about what you have observed and then asking questions. The accuracy of typing is verified by the subject. I call this approach "advance and retreat" as it allows flexibility in arriving at the subject’s type.

The reader may be interested that, according to my experiences, this technique appears to have a greater effect on deceptive subjects. The only reason I see that could possibly explain this is that guilty subjects have a greater fear of being detected. I have also found that some personality types can actually adapt to the interviewer’s personality. This is the reverse of the technique but can explain why some subjects appear truthful when they are actually deceptive. I will explain the complete advance and retreat method in Chapter III.

When the subject's personality type is identified, it is important for the investigator to cross the imaginary line and change his behavior to match the personality type of the subject. This requires effort, and the investigator must make a choice to do it. His motivation is the simple fact that he is more likely to get truthful statements from a subject once he does. It is stressful to behave out of preference. Irritability is a common psychological defense that can be overcome by focusing on the element of choice. What makes this concept of interviewing so effective is the ability of the interviewer to apply specific techniques at will and not have to rely on subjective hunches.

I developed the concept of using personality typing to interview subjects 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.

At the same time as she was conducting her research, Carl Jung, the Swiss psychoanalyst, had developed a theory of personality types. He postulated that an individual's apparently random behavior is not really random at all. If carefully observed, a pattern will emerge that reflects that person's preferences for energy source, taking in information, and making decisions. Additionally, Myers made explicit in her own theory what she saw as implicit in Jung's theory: the concepts of perception and judgment. Using this model, one can see that human behavior is rather orderly and consistent over time. This can best be described with the concept of right and left handedness. Some of us prefer to use our right hand. We do it because it is easier and requires less energy.

Jung published this theory in his book, Psychological Types, in 1923. When Briggs read Jung's work, she found it to be very similar to her own. Together with her daughter, Isabel Myers, Briggs began to integrate her work with that of 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 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 technique presented in this book 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 investigators to understand and effectively deal with human behavior in a variety of situations with predictability. The MBTI is offered on a restrictive basis by Consulting Psychologists Press, Inc.. You can contact them at (800) 624-1765 or through their web page at www.cpp-db.com.

The concept of using personality typing when conducting interviews is not new to experienced interviewers. Many investigators practice elements of the technique instinctively without being aware of the theory that supports it. Knowledge about the logic and "science" behind this instinct can dramatically amplify an investigator’s effectiveness. The bottom line is that using this technique will increase an interviewer’s ability to obtain the truth - and nothing but the truth! If the subject respects and feels rapport with the interviewer, the truth is more likely to come out. This technique is about communicating with subjects in the language that they understand best.