I have a lot of objections to this video, firstly because it is based on a strawman understanding of Jungian theory, but secondly because it disseminates some inaccurate information.
Let’s first distinguish the difference between Jungian psychological preferences and MBTI. Jungian preferences are a set of foundational patterns through which the human psyche apprehends information, known as cognitive functions. MBTI is a flawed assessment and misleading notation system for the prioritization of these functions within the psyche. Ergo, I am not defending the validity of the assessment, but the validity of the theory.
The theory of Jungian psychological preferences (as elaborated upon by John Beebe) is that every person perceives and evaluates information in two ways: perception though the conscious senses and unconscious relationships, and evaluation through objective analysis and subjective values. These functions of the psyche can be described as Sensing, Intuition, Thinking, and Feeling. Further, each of these functions can be oriented towards the external or internal world, resulting in eight defined cognitive functions. All individuals utilize all eight functions, but as they mature their brain develops patterns of prioritizing their utilization, thus strengthening some and weakening others. From these patterns individuals develop values that influence their behaviors, resulting in their personalities. In summary, Jungian preferences are not meant to tell you who you are or to predict what you will become. Rather, they are a framework from which to understand why certain beliefs and behaviors that shape personality are produced.
First, there are actually 32 types, as a person may prefer their auxiliary function over their dominant, and vice-versa.
Second, as seen above, Jung didn’t hypothesize that people fall into 16 personalities. He theorized that there are four processes through which people apprehend information.
Third, the quote “every individual is an exception to the rule” wasn’t meant to discredit Jung’s own theory, but meant to warn against creating specific descriptions for the types because the utilization of cognitive functions is nuanced between individuals. Here is a great post that further elaborates on function dynamics:
https://mbtimyths.tumblr.com/post/146463024022/why-mbti-type-descriptions-can-seem-off
Fourth, it is true that Myers had no formal psychological training, but she performed enough primary and secondary research for an equivalency. This should not discredit her qualifications.
Fifth, the notation of MBTI can be extremely misleading. For example, it would seem from the letter dichotomies that an individual can only hold one preference at a time, such as preferring strictly introversion to extraversion. This is simply not true; as seen in the theory above, all people use all functions at some point. In the case of introversion and extraversion, an individual will display introverted or extraverted attitudes at different times, depending on the functions they are utilizing. For instance, in a moment in which a person uses extraverted feeling, they will appear social and outgoing as they perceive and evaluate information oriented towards their external world; but when they begin to use introverted feeling, they will retreat inward and close off external output in order to engage with processes within their internal worlds. However, if an individual’s dominant function is oriented externally, they will tend to use it more often than their lower functions; thus they appear extraverted more often than introverted.
Sixth, multiple studies have proven the validity of Jungian preferences (I would suggest the work of Francis, Ross, and Village myself, whose works provide comprehensive overviews of past studies.)
Seventh, all personality types are neutral. Positive and negative traits are derived from healthy or unhealthy development and use of cognitive functions, while the functions and their prioritizations remain neutral themselves.
Eighth, a good personality profile will describe the behaviors that tend to arise from the interactions of certain functions based on their prioritization. Good profiles will be derived from observed behavioral patterns between people of identical type. They will not propagate stereotypes based on vague descriptors.
For my ninth and final point, I agree with the video. The MBTI assessment is unreliable due to an individual’s biases and external stimuli that affect perception of self. It is better to be typed through observation by a professional who can evaluate the nuances of your reasoning and behavior in a manner that a standard assessment simply can’t. Yes, this still results in some bias, but the personalization of this method leads to a much smaller margin of error when determining a person’s true type. Here is a great link that further explores why people mistype: https://mbtimyths.tumblr.com/post/181465706862/if-you-think-the-mbti-assessment-is-bullshit
And if you are interested in further exploring the theory, here is a master link:
http://mbti-notes.tumblr.com/post/133156765037/cognitive-function-theory-understanding-typology