Cognitive Functions and Type Dynamics - A Failed Theory?

Many of us are familiar with the cognitive functions (Fe, Fi, Te, Ti, Se, Si, Ne, Ni) and how they are ordered for each type, i.e. type dynamics. 

But questions have been raised over whether cognitive functions and type dynamics actually exist.  Researchers have pointed out the following:

  1. There is no empirical evidence for the existence of type dynamics, which were described by Myers in 1962.  Type dynamics are still purely anecdotal after all these decades.  Why?
  2. Almost no research has been done on whether or not there is such as thing as a tertiary or inferior function.  Who knows if they exist, or what they might be?  At this point their existence is purely speculative, and while there are three different models explaining them, none them have any proof.
  3. Cognitive functions appear to rest mainly upon the authority of Myers' original writings, which were based on the authority of Jung's original writings.  Although the writings have taken on the status of canon, this does not mean that Jung was right to begin with.  In addition, what he wrote was different from what Myers came up with.  Historical precedent does not constitute proof of the cognitive functions' existence any more than it can prove that the Earth is flat.  The fact that everyone has always believed something does not make it correct. 
  4. The fact that the four letter code for a type is empirically solid does not imply that cognitive function theory is also empirically solid.  In fact, they are two separate theories which have been packaged together.  In "basic" (empirically proven) type theory, each of the four letters in the code stands separately, independent of the others' influence.  In type dynamics, the letters are said to interact; this has yet to be demonstrated.  Therefore the valid evidence for "basic" MBTI theory does not by association constitute valid evidence for the existence of type dynamics. 
  5. There have been--and still are--multiple theories about how the cognitive functions are actually arranged, which ones are dominant, how many dominants and auxiliaries there are, and which attitudes are preferred and nonpreferred.  None of these theories have yet been proven.  The best known model is simply the one that made its way into the official MBTI manual. 
  6. There is not yet any study showing that different functions emerge over the course of one's lifespan, or that the development of these functions leads to a midlife crisis.  Therefore these ideas cannot constitute proof for the existence of type dynamics. 
  7. The MBTI manual found some confirmation for type dynamics in the fact that certain types with a dominant function seem to use that function more characteristically than those who have the same function as an auxiliary.  However, the study also found that some types with an auxiliary function used that function in a more characteristic way than those with said function as a dominant.  In short, the evidence actually contradicts itself. 
  8. One study asked non-type-saavy observers to describe types that had, for example, Thinking as their dominant function, by choosing adjectives from a pool of 300 words.  Researchers compared the top 10 and lowest 10 adjectives chosen to describe all types who shared Thinking as their dominant.  The results?  There was little overlap between the sets of adjectives, meaning that little similarity was noticed.  The researchers also compared adjectives for types who shared one of the following: Auxiliary Thinking, dominant Feeling, auxiliary Feeling, dominant Intuition, and auxiliary Intuition. The same results held true for these functions--little to no overlap between the descriptive adjectives chosen.  From these results we can either conclude that a.) too many adjectives were used, offering too much variety and too little chance for any overlap to appear, or b.) Nobody sees type dynamics except those who already expect to see them.  The latter may indicate a simple case of observer bias on the part of psychologists.  And remember, it's all anecdotal at this point, and anecdotes frequently walk hand in hand with observer bias. 
  9. Effects which are often attributed to type dynamics can just as easily be attributed to other things, i.e. a person who is quiet, logical, and thoughtful can be described equally well as a dominant introverted Thinker with auxiliary extraverted Intuition or as an Introvert and an Intuitive and a Thinker (an INT).  There is no reason why one explanation is intrinsically superior. 
  10. Evidence shows that there is little to no factual basis for the hierarchical order of the functions, i.e. there is no proof that dominant > auxiliary > tertiary > inferior.  For example, no one has yet shown that Ti > Ne > Si > Fe for type INTP.  In fact, the evidence fits a random arrangement of functions better, i.e. dominant > auxiliary turns up pretty much just as often as auxiliary > dominant.  In fact, one study did not turn up a single instance where the pattern dominant > auxiliary > tertiary > inferior occurred, as would be predicted for type dynamics.  Rather, random chance appears to determine the order in which functions actually appear. 
  11. Nor is there yet any proof that functions are extraverted or introverted.  A study examined whether dominant functions that are extraverted (i.e. dominant extraverted feeling) turned up more clearly than dominant functions that are introverted (i.e. dominant introverted feeling).  If type dynamics theory is true, then those who extravert their feeling function should show it more clearly and obviously than those who introvert it.  But no differences were noted by observers; in fact, traits of both extraverted and introverted dominant functions were seen as being just as clear and obvious by observers.  By contrast, when "plain vanilla" type theory was used, it could be seen that an ENTJ (for example) displayed intuition and thinking in a clear, obvious way, whereas an INFP (for example) displayed intuition and feeling in a less clear and obvious way.  The difference, then, is due to plain, simple Introversion and Extraversion, and not to the type dynamics explanation that certain parts of oneself are either introverted or extraverted. 

Back in the days of Galileo and Copernicus, the official canon was that planets traveled in perfect, harmonious circles.  But then proof began to appear that planets actually revolved in messy, imperfect ellipses.  Horrors!  There must be some mistake. 

The "official" scientists squirmed, trying to shoehorn the observations into established paradigms of circular motion.  They invented "cycles" and "epicycles" where planets revolved in small circles within their normal, larger circles.  Complicated systems of cycles and epicycles were invented--all to no avail.  The evidence simply did not match circular motion, no matter how hard they tried to justify it.  Finally Occam's razor and the K.I.S.S. principle prevailed. 

Once people grudgingly accepted the evidence, they discovered that elliptical motion really wasn't as bad as it had seemed all those years ago.  In fact, it was kind of cool in its own right. 

Type dynamics evokes this historical scenario all too well.  Here we have a theory which still has not been proven in spite of efforts, which never had any proof in the first place, and which does not fit existing observations in any of its multiple variations. 

But type dynamics is still very useful--it conveniently explains away any contradictions to type theory that may pop up. 

Type dynamics allows introverts to behave like extraverts and thinkers to behave like feelers.  And so there is always a ready-made excuse to justify any inconvenient deviations from the code that might turn up.  Circular motion theory doesn't fit elliptical observations?  Just throw in an epicycle or two; all better.  The more ambiguous and complicated your theory is, the easier is it to justify contradictions that might otherwise discredit it. 

But that leaves us with a little dilemma, doesn't it?  If we get rid of type dynamics, then how do we explain observations that don't fit the basic MBTI theory?  I.e., what if you have a person who says, "I think I'm a Judger because I like having a clear plan, but my desk is always messy"?

Happily for us, an alternate explanation to type dynamics exists that is simple, does not require unproven theoretical constructs, and fits the existing data well.  Let's examine this alternative. 

A Better Alternative to Cognitive Functions and Type Dynamics

The replacement scheme proposed by Reynierse drops type dynamics entirely.  Instead, a person’s letters (for example, INTP) are ranked in order of “strength.”  And what is meant by strength, exactly? 

Well, when you took the Myers-Briggs test (or any of the other MBTI knockoffs floating around) you probably noticed that some of your personality traits--i.e., Thinking, Feeling or whatever--were very clear and obvious, i.e. you answered 9/10 questions as a Thinker rather than a Feeler.  For other personality traits, perhaps Sensing vs. Intuition, you might have noticed that you were pretty middle-of-the-road in that you didn’t have much preference for either way of functioning.  For example, perhaps you only answered 6/10 questions as an Intuitive.

In the traditional way of looking at type theory, it doesn’t matter whether your preference for any particular letter is clear or slight--a letter is a letter is a letter.  If you answer 10/10 questions about Introversion vs. Extraversion as an Introvert, then it is considered the same thing as if you had answered only 6/10 questions as an Introvert.  In short, the strength of each preference was ignored.  As one MBTI practitioner put it, "You're either pregnant or you're not."  However, it turns out that this information has predictive value and can actually be useful in understanding one’s own unique personality.  

If we put each of the traits on a spectrum, i.e. E – I, S – N, T – F, and J – P, allowing for shades of grey rather than just black/white, yes/no choices, we can get a much clearer picture of an individual's unique personality. “Types” become simplified representations of the spectrum, the way a rainbow is divided up into six colors rather than a million different shades. The goal is to find a scheme that adequately represents this added complexity without becoming too overdetailed to be useful.

Example: An NTIP

For example.  Let us suppose that a person tests with the following:

  • 10/10 preference for Intuition

  • 8/10 preference for Thinking

  • 8/10 preference for Introversion

  • 6/10 preference for Perceiving

These preferences indicate an INTP, but more than that, they indicate an NTIP.  This “NTIP” has Intuition as their strongest preference and will be most skilled at making connections and seeing patterns and relationships.  Compared to the other INTP variants (INPT, TPNI, etc), this person has only a slight preference for Perceiving, and thus they may be almost as comfortable using Judging as Perceiving.  

Example: A TNPI

Suppose that a person tests with the following:

  • 10/10 preference for Thinking

  • 9/10 preference for Intuition

  • 8/10 preference for Perceiving

  • 6/10 preference for Introversion

Using our ranking system, we would identify this person as a TNPI.  As a strong Thinker, the TNPI would be most skilled at logic, reasoning, and task-oriented analysis.  Intuition, which was almost as favored, will also be strongly preferred, at the expense of skills in Sensing.  The least favored preference, i.e. Introversion, indicates that the TNPI will demonstrate Introversion only slightly more than Extraversion.  Thus, they would be better than the average INTP at interfacing with the outer world, but they would also sacrifice something of the inner world of Introverts.  Incidentally, people who have neither a strong preference for Introversion or Extraversion are called Ambiverts.

Note: Being a middle-of-the-roader has its own particular “amphibian” benefits, in that the person is able to straddle the boundary between land and water and enjoy the benefits of both sides.  People with slight preferences are favored to succeed in situations where frequent flipflop between preferences is necessary, or when success hinges on a balance of skills.  However, just as a frog cannot swim as well as a fish nor run as well as a dog, so a middle-of-the-roader is not as favored for success in situations where one preference is consistently or strongly required (in this case those with clear preferences are favored).  So, having a slight or clear preference is neither good nor bad; it merely indicates which unique ecologic niche you operate best in.  And since there are all kinds of niches in this world, all kinds of preference strengths are necessary to keep things running. 

Non-Preferred Functions

Since we acknowledge that the strength of one’s preferences is important, and that a person with a slight preference may exhibit nearly as much of one preference as the other preference, it is good practice to note the non-preferences at the end of the basic letter code.  So for example, an NTIP is really an NTIPjefs--meaning that they will use Sensing the least of all possible preferences and Intuition the most of all.  By a similar token, a TNPI is actually a TNPIejsf--meaning that this person will use Feeling the least of all their possible preferences and Thinking the most.  Note that the lower-case non-preferences will always be an exact mirror of the upper-case letters of the preferences.  The last four letters aren’t a “shadow” or “inferior”--they are preferences in their own right, albeit less used ones.  Indeed, for a person who has several borderline 6/10 functions, the lowercase trailing letters may be almost as important as the upper case letters.  Thus it is proper to include them. 

Strong Preference(s)

There is no reason why a person cannot have more than one strong prefence.  Suppose that an INTP has both very clear I and very clear P, and both preferences are 10/10 when measured on a test?  In this case, we can designate this INTP as (say) an IPTNsfje, underlining the top preferences to show that they are clearest.  

It is possible to have one, two, three or even four strong preferences.  It is also possible to have no preferences at all. 


The theory above explains individual variation without the need to resort to unproven hypothetic constructs, namely type dynamics and cognitive functions.  Furthermore, it is empirically sound and can be measured on a test.  It also matches up with existing field observations.  As a simpler and more elegant solution, it deserves consideration within the internet type community as an alternative to an increasingly shaky theory. 


  • Reynierse, J. H. (2009).  The case against type dynamics.  Journal of Psychological Type, 69, 1-21.
  • Reynierse, J. H. (2012).  Towards an empirically sound and radically revised type theory.  Journal of Psychological Type, 72, 1-25.
  • Reynierse, J. H., & Harker, J. B.  (2008a).  Preference multidimensionality and the fallacy of type dynamics: Part 1 (Studies 1 - 3).  Journal of Psychological Type, 68, 90-112.
  • Reynierse, J. H., & Harker, J. B.  (2008b).  Preference multidimensionality and the fallacy of type dynamics: Part 2 (Studies 4 - 6).  Journal of Psychological Type, 68, 113-138.