INTP Mailing List Frequently Asked Questions

Version 1.1

May 30, 1997

2 The INTP Personality

2.1 What is an INTP?

An INTP is an Introverted iNtuitively Perceiving Thinker. INTPs prefer to take in information (_perceive_ reality) by using intuition rather than the five senses, and prefer to make decisions about that information (_judge_ reality) by using thinking (logic and reasoning) rather than by considering the effects of the decisions on other people. As Perceivers, INTPs prefer to use the perceiving function (iNtuition) to deal with the external world, and to devote the judging function (Thinking) to their internal world (see question 2.7). As Introverts, INTPs prefer this internal world; they are not enthused and energized by interacting with other people but by being alone.

2.2 What do you mean by "perceiving function" and "judging function?"

These are terms from personality type theory. See section 3, particularly questions 3.3, 3.4, and 3.5, for information about this.

2.3 What are some of the personality characteristics of INTPs?

The notions given in question 2.1 suggest a number of characteristics of the INTP personality. Since INTPs prefer to use their perceiving function to relate to the outside world, and since they perceive (gather information) intuitively, they can seem "absent-minded," "spaced out," "uninvolved," or "not all there" to people who are more strongly grounded in concrete sense perceptions. Yet, they often seem to have uncanny insights that less intuitive individuals do not have. Since they prefer to make decisions based on logic and reasoning, they can seem "cold," "impersonal," or "unemotional" to people for whom thinking and reasoning take less of a priority. However, they are frequently indomitable in arguments, able to marshall point after point in favor of their position.

As Introverts, INTPs may seem like "loners" or "hermits" to many. But an INTP is usually quite content to be alone with his or her thoughts and mental ruminations. Indeed, since an INTP's preferred orientation is toward his or her internal world (Introversion), and since he/she uses her/his judging function (Thinking) in that internal world (the perceiving function being used in the external world), Thinking is the INTP's preferred, or _dominant_, function. (The INTP's perceiving function (iNtuition) is called the _auxiliary_ function, and is the second most preferred function.) Thus, thinking is an INTP's forte, and INTPs are always thinking. The raw material for these ceaseless thought processes comes from the intuitive insights that the INTP's perception supplies. INTPs build mental models of reality based on their intuitive perceptions.

Only rarely--and reluctantly--do INTPs share what they are thinking, however (though the private and impersonal nature of the INTP Mailing List seems to have loosened many of their tongues; see question 1.18). Neither are they prone to act on their thoughts; with Thinking as their dominant function, they prefer instead to continually revise their mental models as their perceiving function supplies them with additional data. Thus, their external world tends to be unstructured (and, unfortunately, in some cases unaffected) by their thinking. Many mistakenly interpret the characteristic silence and inaction of INTPs as supercilious disinterest, intellectual snobbery, boredom, rudeness, aloofness, or lack of appreciation. It could be one or several of these, but more likely the INTP is deeply interested and involved mentally, busily thinking within his or her own personal and idiosyncratic context.

An INTP, then, is constantly making logical, systematic judgements or decisions about information gleaned through leaps or flashes of intuition. As a result, an INTP is oriented toward the theoretical. They habitually seek to get "behind the scenes" of reality. They are "big picture" people; they are "possibility" people. In _Please Understand Me_ (see question 3.17), Keirsey and Bates write,

The one word which captures the unique style of INTPs is _architect_ [sic]--the architect of ideas and systems as well as the architect of edifices. (p. 186)

INTPs are generally adroit, natural, creative, and non-linear thinkers who accept few boundaries to their intellectual meandering. Although many display periods of manic intensity, compulsiveness, or coma-like behavior, underlying their seemingly intense, detached, distracted, gruff, and serious INTP persona is wonderment, child-like contemplation, and a generally playful irreverence.

2.5 I seem to [insert observed behavior here] a lot. Is this typical of INTPs?

There are a number of behaviors mentioned often enough on the list that it is reasonable to assume they are typical of INTPs. Frequently, new subscribers will express astonishment that there are others who do these things (see question 3.6). (However, people of the same personality type are neither clones nor--usually--twins, so not all INTPs necessarily exhibit all these behaviors. See also question 2.4.)

2.5.1 Observed behavior: [have a messy desk; keep stuff]

INTPs usually seem to be "pack rats," at least to some degree. Many INTPs report having "messy" desks and/or living areas, often with piles of books and papers awaiting attention. (There can be _lots_ of books.) The INTP's desire to learn almost everything, together with the perceiving attitude that makes the INTP always open to new information, contribute to a reluctance to get rid of anything that might possibly be of value. Actually filing such material would impose a structure on it which might need to change "tomorrow."

Where SOs, roommates, or coworkers are of a different type, the INTP often must accommodate foreign preferences by confining "true" manifestations of his/her personality to certain parts of the home or office.

2.5.2 Observed behavior: [be unscheduled; miss appointments]

INTPs prefer an unstructured approach to living and to getting things done (see questions 2.3 and 2.8). They do not, therefore, do well with schedules. To an INTP, time is an open-ended entity that is allowed to unfold, not a resource to control.

Many INTPs have learned to control at least a portion of their time, however, in order to function in the predominantly SJ world of which they are a part (see again question 2.8). Some can be quite successful at this. Nevertheless, the behavior is not their true preference.

2.5.3 Observed behavior: [bounce from one interest to another]

INTPs tend to have a multitude of interests. This pertains not only to their work life (see question 2.8), but to other areas of their life as well. Hobbies, diversions, books to read, magazine subscriptions: the INTP may well have many of these, and may well change them like some people change clothing.

Unfortunately, most INTPs have the dilemma of "so many interests, so little time," and are usually unable to satisfy their curiosity in more than a few of their areas of interest. Sometimes, because of a problem with making decisions (see question 2.5.5), an INTP is unable to choose which interests to pursue and risks a life of underachievement and boredom.

2.5.4 Observed behavior: [not complete projects as interests change]

INTPs enjoy novelty and variety and they often lose interest in something once they "understand" it (see question 2.8). To them, the project has been "completed" and there is no need for further work to "implement" anything. Thus, raw materials for one project after another can pile up as an INTP develops an interest, "researches" it, begins gathering materials, "understands" it, and moves on to the next interest.

2.5.5 Observed behavior: [have difficulty making decisions]

INTPs prefer life to be unstructured, and they remain open to new data (see questions 2.3 and 2.8). Because of this, they often resist (frequently without conscious awareness) finalizing, or "coming to

closure," on an endeavor. This can lead to putting off even important decisions, and sometimes can bring about an actual fear of decision-making.

2.6 How common is the INTP type?

According to Keirsey and Bates in _Please Understand Me_ (see question 3.17), only about 1 in every 100 people is INTP. Using somewhat different figures from Lawrence, _People Types & Tiger Stripes_ (see question 3.17), the figure could be as high as about 2.5 in every 100 people. In any case, it is clear that INTPs are rare, which probably accounts for the sense of alienation many INTPs report.

The INTP type is slightly more common among males than among females. See also question 3.9.

2.7 What types are best for relationships with INTPs?

This question is asked often on the list, because INTPs seem to have special difficulty forming relationships of any kind. Their tendency to ignore or misinterpret common social cues hampers entry into many social milieus, and their disdain for the social lubricant of "small talk" prematurely betrays their intensity (an intensity which, in the initial stages of a relationship, can be disconcerting and can make them appear unapproachable, even arrogant). Their characteristic emotional unexpressiveness makes maintaining close personal relationships a challenge for partners who need feedback and intimacy.

But don't panic. Nearly all types have been mentioned at one time or another as a good (or a bad) match for INTPs, and, as with many other topics on the list, discussion about good matches takes a different direction every time the question is raised. INTPs have formed successful relationships with all types (and have had predictable difficulties with all types). You will find advocates for most types.

More significantly, however, this is the wrong question when it comes to choosing an SO. Common goals and values, similar interests, and similar world views or tolerance and respect for diversity are more important than type. What matters is how couples think of each other and how important their differences are _to them_. Can they tolerate the differences, adjust to them, or even be attracted by them?

Some commonly mentioned "trigger points" for problems in relationships with INTPs:

· Will the SO rearrange the INTP's desk or clean up (e.g., store books) but the INTP prefers some "ordered chaos?"

· Will the SO expect the INTP to participate in big family gatherings and join in social chit-chat late into the night?

· Will the SO understand the INTP's need for solitude to recharge and not see it as an attempt at avoidance?

· Will the SO criticize the INTP for being too withdrawn, too unempathetic, too disorganized, too pedantic, etc.?

In _16 Ways to Love Your Lover_ (a very good book on type and relationships; see question 3.17), Otto Kroeger & Janet M. Thuesen advise INTPs to speak from the heart. When INTPs try to use thinking to express love, the meaning can get lost in the translation. They should share the fact that they _feel_ love, not only _understand_ it. INTPs are slow to communicate, but this does not mean that things are not simmering and smoldering inside. Although they appear aloof, snobbish, and disinterested in small talk at first, they are intriguing and, when comfortable, can be engaging conversationalists. At more advanced stages of a relationship, their rich imagination can "create an inferno of explosive and expressive affections" (p. 253).

If an INTP finds that none of the non-INTPs he/she meets seems compatible, there may be some comfort in knowing that the list has spawned an occasional INTP-INTP relationship, and includes an INTP couple who love to discuss their happy and successful 28 year marriage and children. (But don't get the wrong idea about why we're here: The purpose of the list is eclectic and desultory discussion, not matchmaking!)

It is interesting to note that even the so-called experts disagree and are often inconsistent on this topic. Keirsey and Bates, on p.17 of _Please Understand Me_ (see question 3.17), warn that mismatches in the perceiving functions (Sensing and iNtuition, the functions by which we take in information and by which, therefore, our world view is influenced; see question 3.4) are "the source of the most miscommunication, misunderstanding, vilification, defamation, and denigration." But later, in Chapter III, they claim people areattracted to their exact opposite. Kroeger & Thuesen, on the other hand, on p. 27 of _16 Ways to Love Your Lover_, claim that the most significant source of interpersonal tension is the difference between the Perceiving and Judging attitudes (P vs J). These attitudes determine whether someone prefers to use their perceiving (information-receiving) function (S or N) or their judging (information-processing) function (T or F) in dealing with their external world (see question 3.5). Perceivers, who prefer to use their judging function on their _internal_ world, are usually easy-going and wait-and-see towards _external_ circumstances, while Judgers, who prefer to use their judging function on their external world, are decisive and resolute towards external circumstances. To Perceivers, Judgers can seem stubborn, unyielding, non-adaptable. To Judgers, Perceivers can seem flighty, indecisive, unorganized, spaced-out. In a relationship, these differences can escalate from minor irritants to major conflagrations.

On p. 83 of _Portraits of Temperament_ (see question 3.17), Keirsey briefly re-evaluates the best romantic matches for each type under a new typing system of his own creation. There, he claims that the best match for the "Engineer" type (which correlates with the Myers-Briggs NTP type) is the "Idealist" type (which correlates with the Myers-Briggs NF type). He argues that Idealists are aware of and attracted to the Engineer's ingenuity and are very encouraging of it, and that the Idealist serves as a source of endless mystery to the rational nature of the Engineer. He goes on to allow that Engineers can safely marry some of the other types but it will require more personal adjustments.

From the other perspective, on p.94 of _Portraits of Temperament_ Keirsey claims that the best match for the "Mentor" type (which correlates with the Myers-Briggs NFJ type) is the NTP Engineer. He argues that Mentors, while they may mate successfully with any of the types, face fewer adjustments when they mate with Engineers. Engineers value a Mentor's "appreciation and encouragement, their compassion, and their vivacity; while Mentors appreciate being needed for something they have in plenty."

Clearly, the question is still open and unresolved. It will probably (and perhaps rightly) remain so.

2.8 What jobs or career fields are best for INTPs?

The preferred function for INTPs is Thinking, oriented towards the inner world of ideas, concepts, and mental models (see question 2.3). To satisfy this preference in their work, INTPs require jobs where their primary responsibility is to apply their thinking to underlying principles, abstract notions, and other theoretical structures. However, these structures need not be scientific hypotheses or involve technical speculation; depending on the specific interests of the INTP, they can be plans, procedures, methods, or explanations of almost any sort. INTPs formulate these, analyze them, generalize them. The results of their quiet thinking can speak loudly to those who care to listen.

Because of their introversion and their intuitive perception (see again question 2.3), INTPs function best in situations where they are not required to have much contact with other people and where they need not exercise strong "sensing" elements. They are not necessarily interested in or concerned with tangible products, except insofar as these exemplify and embody their ideas and theories. Therefore, they tend to avoid pragmatic jobs. Since they prefer the "big picture," the overall view, they usually do not enjoy detail work unless it can be seen as contributing to some larger task or goal that is important to them.

As Perceivers, INTPs prefer openness instead of closure in their external world. Thus, they favor work situations where they can have a great deal of autonomy. Compulsory tasks, deadlines, and schedules are distasteful to them. They enjoy novelty and variety rather than routine, repetitive assignments.

An INTP's involvement with something typically lasts until the INTP understands it or until her/his interests shift to something else. For this reason, INTPs usually do not fit well into jobs that ask for a "Team player who can take an idea from conception to production." Such jobs, in fact, require almost the very antithesis of the INTP personality. Because of their tendency to change from one pursuit to another to another, INTPs have been called ". . . the quintessential Jacks (or Janes) of all trades and masters of none" (Kroeger and Thuesen, _Type Talk_, p. 246).

Unfortunately, in the conventional world of work most of an INTP's personality traits are seen not as assets but as liabilities, and many INTPs appear to have difficulty finding compatible employment. Numerous INTPs on the list report "job-hopping" from one position or career to another as their interests change, or in pursuit of "something" they want or like to do. Some attain satisfaction in this way, but not all INTPs can make repetitive job changes. To earn a living in a society which is predominantly SJ, INTPs often need to assume foreign personas for at least part of their work day. Sometimes this is done at great psychological cost.

Still, there are INTPs who have found occupational happiness. Many INTPs enjoy working with computers, and a great number of subscribers to the list are programmers, analysts, system administrators, or computer consultants. INTPs who have the requisite credentials often find satisfaction in the world of academia. Those who are not technically inclined tend to other lines of work involving complex systems, such as the law or psychology. INTPs can even be content as artists, writers, or musicians; in each of these fields, their faculties for dealing with intellectual intricacy can be put to use and challenged. On the INTP Mailing List there are academics, lawyers, psychologists, artists, writers, and musicians. There is also at least one stockbroker.

A few INTPs may choose to hold routine jobs that require little thought and effort, to earn a subsistence income and devote their free time to their "true" calling. This can be a viable option, at least for a while (for example, it is well known that Albert Einstein--an archetypal INTP--developed his Special Theory of Relativity while holding a routine civil service job in the Swiss Patent Office); as family responsibilities increase, however, there can be both less free time and a need for more than subsistence wages. Some INTPs have reported success functioning in totally foreign environments by treating the many rules and constraints as a complex "game."

It would seem that there is no "best" career or job for INTPs, and few that are even reasonably suited. Perhaps the best advice is from Joseph Campbell: "Follow your bliss." An INTP should not avoid a job he or she might like simply because it seems unsuitable from a type standpoint. Yet, neither should he/she expect to be able to exercise all her/his gifts and to find complete fulfillment in only a conventional occupation.

3.2 What do you mean by "personality type?"

An individual's "personality" is his or her overall pattern of behavior. This includes internal behavior, such as thoughts and feelings, and external behavior, such as ways of acting in certain circumstances or ways of dealing with various people. Although each of us is a unique individual, humans have been observing, characterizing, and grouping other humans based on behavior since ancient times. This is a natural activity that helps us make manageable sense out of the great variety of behavior we encounter among the people we meet. For example, in the fifth century BC, the Sicilian philosopher Empedocles spoke of four bodily fluids, or "humors," which he believed influenced people to be one of four kinds of person: melancholic, phlegmatic, choleric, or sanguine. Today, some people find the Enneagram helpful in understanding themselves or others. Many of us know individuals of whom we say, "He is very outgoing," or "She is the meanest person I've ever met." Any such characterization or grouping can be said to be a system of personality typing.

In the first half of the twentieth century, the great Swiss psychiatrist and psychoanalyst Carl Jung wrote extensively about this. Building on Jung's work, Katharine Briggs and her daughter Isabel Briggs Myers developed their concept of sixteen personality types and created a simple written instrument, the Myers-Briggs Type Indicator, to help an individual determine his or her type.

3.3 How does this "Indicator" work? What is the theory behind it?

Human beings are constantly taking in and processing information. In Jungian type theory, the action or "function" of our personalities by which we take in information, or _perceive_ reality, is called the

"perceiving" function, and the action or function of our personalities by which we process information, or _judge_ (make decisions about) reality, is called the "judging" function. Jung maintained that humans have two fundamentally different ways of taking in information (two different perceiving functions), and two fundamentally different ways of processing information (two different judging functions). The central tenet of type theory is that each person develops a preference for using one of the two perceiving functions and for using one of the two judging functions. Individuals with similar preferences behave in similar ways; individuals with different preferences behave in different ways.

3.4 What are the different perceiving and judging functions?

The two perceiving functions are "Sensing," in which one relies primarily on one's five senses to take in information, and "iNtuition," in which one relies primarily on some "hunch" or "sixth sense." Those

who prefer the "Sensing" function to receive information are designated "Sensors;" those who prefer the "iNtuition" function to receive information are designated "iNtuitives."

The two judging functions are "Thinking," in which one relies primarily on logic and reasoning to make decisions about the information one has perceived, and "Feeling," in which one relies primarily on the effects one's decisions will have on other people to make decisions about the information one has perceived. Those who prefer the "Thinking" function to process or make decisions about this information are designated "Thinkers;" those who prefer the "Feeling" function to process or make

decisions about this information are designated "Feelers."

Thus, each individual falls into one of four groups or categories, and is identified by the letters S or N and T or F: ST, SF, NT, or NF.

3.5 But this gives only two letters for each "type," not four, and only four "types," not sixteen. Where do the other letters come from?

Jung also noticed that most people have one of two preferences for social interaction. Those who are enthused and energized by being with people he called "Extraverts;" Extraverts are uncomfortable when they are alone and spontaneously seek the company of others. Those who are enthused and energized by being alone or with a few close friends he called "Introverts;" Introverts are uncomfortable when they are with other people and spontaneously seek solitude. Using the letter E to designate Extraverts and the letter I to designate Introverts, the four large groups become eight: EST, IST, ESF, ISF, ENT, INT, ENF, INF.

Myers and Briggs realized that most people prefer to use one of their information-related functions--either their information-receiving function (S or N) or their information-processing function (T or F) in

dealing with their external world. Those who prefer to use their perceiving function to deal with their external world they called "Perceivers" and designated by the letter P; those who prefer to use their judging function to deal with their external world they called "Judgers" and designated by the letter J.

This gives a total of sixteen groups, or types, into which most people can fit. Arranged in a (traditional) "type table," the sixteen types are:

ISTJ ISFJ INFJ INTJ

ISTP ISFP INFP INTP

ESTP ESFP ENFP ENTP

ESTJ ESFJ ENFJ ENTJ

3.6 This all sounds like a lot of psychological mumbo-jumbo to me. Is there any validity to it?

The MBTI is a widely respected psychological instrument that is extensively used by government, business, and academic organizations, as well as by counselors, psychologists, and psychiatrists in private practice. While there are other "systems" for categorizing personality (see question 3.17), and the MBTI does have its critics, no other "system" seems to have its interest and appeal.

Frequently on the INTP Mailing List, a newcomer will express surprise (and, often, relief) that others on the list seem so like him or her (occasionally after years of feeling alienated from "mainstream"

society). Or a subscriber will report that learning about the MBTI finally allowed him or her to realize there is nothing "wrong" with the way he or she is.

Ultimately, each of us must decide for ourselves how valid are the insights into our personality offered by the MBTI.

3.7 Doesn't all this "categorizing" and "grouping" stereotype people, and limit them based on someone else's preconceived ideas?

It is impossible to conceptualize knowledge in any field without some categorizing and grouping of the entities involved. As a field develops, the results put forth by early workers are subject to amendment or correction by others, until, gradually, the phenomena described are trusted to accurately represent reality. In typology, the reactions of many who have achieved insights into their own personalities through the MBTI serve to bear out the theory.

More importantly, however, the MBTI never presumes to be anything approaching a "final" answer to the mysteries of human personality. Each person who takes the inventory is encouraged to read several or all of the type descriptions to validate the instrument's results. And each is told, explicitly, "You are the final arbiter of your own type." That is, if the MBTI "says" you are INTP but you, after sufficient research into and reflection on other types, feel that another type fits you better, then you are free to decide you are that other type. MBTI results can be affected by many factors, and should be considered one component in an entire constellation of components that reveal one's psychological type.

3.8 Does being a certain type mean my behavior is predetermined?

The Myers-Briggs Type Indicator is an _indicator_; it is not an absolute determiner of someone's personality and behavior. Furthermore, the MBTI indicates _preferences_, i.e., how one likes to behave. Anyone at anytime can choose to use an opposite preference.

Using an opposite preference is difficult and psychologically exhausting, however. It cannot be done constantly. To understand this, sign your name with the hand you normally use. Then, below the first

signature, sign your name with the other hand. Although you can use your non-preferred hand, it takes effort (for some, much effort). And the result is not as good.

3.9 Which type is most common?

According to Keirsey and Bates in _Please Understand Me_ (see question 3.17), the approximate percentages of people who have the various types are:

ISTJ - 6% ISFJ - 6% INFJ - 1% INTJ - 1%

ISTP - 5% ISFP - 5% INFP - 1% INTP - 1%

ESTP - 13% ESFP - 13% ENFP - 5% ENTP - 5%

ESTJ - 13% ESFJ - 13% ENFJ - 5% ENTJ - 5%

According to Lawrence, _People Types & Tiger Stripes_ (see question 3.17), p. 39, the distribution of preferences is:

E - 70% I - 30%

S - 70% N - 30%

T - 60% F - 40% among males

T - 40% F - 60% among females

J - 55% P - 45%

Clearly, INTPs are among the rarest of the types.

3.11 I sometimes see additional symbols used in someone's type designation. What do these mean?

On the INTP Mailing List, some conventions are used for showing the strengths of one's various preferences. A lower-case letter denotes a weak preference relative to the other preferences; an asterisk _after_ a (capitalized) preference denotes an extremely strong preference relative to the other preferences. This system is set forth every two weeks in the biographical list ("bio list") posting (see question 1.19). Thus (from the biographical list),

InTP: weak N preference and moderate to strong preferences for I,T,P

IN*TP: extremely strong preference for N

IxTP: borderline N/S score; not clearly N or S

3.14 How can I find out someone else's type?

The best way to find out another person's type is to ask them. But this is not always feasible. Some people whose type we might like to know are not familiar with MBTI, and some people who know their type do not wish to share it. (It is important to respect the wishes of those who do not care to give this information.) Some people we cannot ask: what was Abraham Lincoln's type, for example?

It is possible, though, to _estimate_ another person's type by carefully observing their behavior (because personality manifests itself in behavior). However, we can only see another's external behavior, not their internal behavior (see question 3.2). Furthermore, unless their behavior results from well-developed type preferences, we might not make a correct determination; someone with a weak preference for introversion or extraversion, for instance, might be mistaken for their opposite

type. And it is important to remember that the circumstances under which we observe a person might cause them to behave differently than they would prefer to behave, so that we might not be seeing their "real" self. Thus, by observing someone we can pick up useful clues to their personality type, but we can never be absolutely sure of it unless they themselves tell us (and sometimes not even then: occasionally, someone has a difficult time deciding on their _own_ type).

Perhaps the easiest characteristics to discern are introversion versus extraversion and judging versus perceiving. Someone who often attends parties and who obviously enjoys other people is almost certainly an Extravert, while an individual who is usually seen alone in a corner with a book or magazine is probably an Introvert. Judgers, who use their judging (decision-making) function on their external world, typically impose some sort of noticeable structure on that world by their decisions. Often, this structure can be seen in their physical surroundings or in their use of resources (such as time and money). Thus, someone whose work and/or living areas are "neat," "tidy," or organized is probably a Judger, as is a person who commonly seeks finality or completion ("closure") in their external activities. Judgers also are usually more concerned about "rules" and about observing them, and about their personal appearance; a precise dresser is more likely to be a Judger. Perceivers, who use their perceiving (information-gathering) function on their external world, reserve decision-making for their internal world. As a result, Perceivers take a "live and let live" attitude toward their external world and are frequently regarded as "disorganized" or "messy." Someone whose desk is replete with piles of paper, magazines, and books, who seems casual and unconcerned about time, money, personal appearance, or rules, is probably a Perceiver. (Many Perceivers, however, while maligned as "disorganized" because of their external behavior, can be quite organized in their internal world of thoughts and ideas. This is particularly true of INTPs.)

Determining the other attributes is more challenging, and requires a good knowledge of the other person and of type theory. Otto Kroeger and Janet M. Thuesen discuss determining other peoples' types in their very helpful book, _Type Talk_ (see question 3.17).

3.17.1 Category of reference: [books]

Benfari, Robert, with Jean Knox. _Understanding Your Management Style:

Beyond the Myers-Briggs Type._ Lexington, MA: Lexington Books, 1991.

Bridges, William. _The Character of Organizations: Using Jungian Type

in Organizational Development._ Palo Alto, CA: Consulting

Psychologists Press, Inc., 1992.

Briggs-Myers, Isabel, and Peter Myers. _Gifts Differing._ Palo Alto,

CA: Consulting Psychologists Press, Inc., 1980.

Corlett, Eleanor S., and Nancy B. Millner. _Navigating Midlife: Using

Typology as a Guide._ Palo Alto, CA: CPP Books, A Division of

Consulting Psychologists Press, Inc, 1993.

Jeffries, William C. _True to Type: Answers to the Most Commonly Asked

Questions About Interpreting the Myers-Briggs Type Indicator._

Norfolk, VA: Hampton Roads Publishing Company, Inc, 1991.

Jung, C.G. _Psychological Types_. In _Collected Works_, vol. 6,

translated by R. F. C. Hull. Princeton, NJ: Princeton University

Press, 1976.

Keirsey, David, and Marilyn Bates. _Please Understand Me: Character &

Temperament Types._ Third edition. Del Mar, CA: Prometheus Nemesis

Books, 1978.

Keirsey, David. _Portraits of Temperament_. Second edition. Del Mar,

CA: Prometheus Nemesis Books, 1991.

Kroeger, Otto, and Janet M. Thuesen. _16 Ways To Love Your Lover:

Understanding the 16 Personality Types So You Can Create a Love That

Lasts Forever._ New York: Delacorte Press, Bantam Doubleday Dell

Publishing Group, Inc., 1994.

Kroeger, Otto, and Janet M. Thuesen. _Type Talk at Work: How the 16

Personality Types Determine Your Success on the Job._ A Tilden Press

Book. New York: Delacorte Press, Bantam Doubleday Dell Publishing

Group, Inc., 1992.

Kroeger, Otto, and Janet M. Thuesen. _Type Talk: The 16 Personality

Types That Determine How We Live, Love, and Work._ A Tilden Press

Book. A Delta Book. New York: Dell Publishing, a division of Bantam

Doubleday Dell Publishing Group, Inc., 1988.

Lawrence, Gorden. _People Types & Tiger Stripes: A Practical Guide to

Learning Styles._ Second edition. Gainesville, FL: Center for

Applications of Psychological Type, Inc., 1982.

Quenk, Naomi L. _Beside Ourselves: Our Hidden Personality in Everyday

Life._ Palo Alto, CA: CPP Books, A Division of Consulting

Psychologists Press, Inc, 1993.