The eight function model, made popular by John Beebe, is a popular theory of behaviour because it suggests that people don’t have just one dominant personality but eight different sides that they manifest depending on their mood and health. For example, a person can act differently depending on if they are in the grip of their shadow, their demon function, or their inferior function, and the idea is that this can cause dramatic changes in our behaviour. Negative behaviour is said to be the result of unconscious issues in the shadow while positive behaviours are associated with the conscious and dominant aspect of your personality.

The eight function model is built on the theory of Carl Jung – who suggested the mind might rely on 8 distinct processes or cognitive functions, but specifically, what I take issue with in this article is not Jung, but rather, an interpretation of Jung’s theory developed by John Beebe.

Preventing the use of The MBTI As An Excuse

The eight function model then is a popular theory of why people do bad things – because they’re under the influence of their shadow, or trickster, or the witch/senex. In mainstream psychology though, this view is looked at with scepticism. A person who has a holistic and integrated personality, which is relatively consistent and stable over time, is considered healthy, while a person who has a dissociative identity or multiple personalities, is said to be suffering from a disorder. Carl Jung too, argued that a goal of psychology was to help patients achieve an integrated sense of self, rather than compartmentalize it to multiple parts.

So to think of yourself as influenced by a “Trickster” or “Demon” or “Witch” could be directly unhealthy, as it suggests you’re not in control or possession of yourself, but rather, that there are elements inside of you that are working “against” you or to undermine your dominant personality. A psychologist would rather foster a sense of empowerment and conscious awareness, by helping you put yourself in different situations and to recognize and think honestly about what you did and why you did it. This helps you process through negative experiences and traumas and helps you gain a sense of awareness.

The MBTI is not meant to be an excuse.

Preventing The MBTI From Becoming Pure Astrology

Core criticisms against the eight function model rest in that it’s theories are poorly defined. Whatever does it mean that something is a demon or a trickster? How can we understand this in a practical light? A comparison can be drawn to the popular idea in astrology that our personality moves between different houses, and so, when mars is in the third house, you might act in a certain way. This is similar to how a person might say that because their Introverted Intuition is in the 7th house, they are going to act in x or y manner. When you think about it in this way, it’s understandable why the eight function model, as it can serve as a comprehensive rosetta stone or explanation of everything. Any actions that I take, are the result of my personality. But this is a common fallacy.

In psychology, it’s understood that you don’t engage in x form of behaviour because you have y diagnosis. It’s rather the case that you have y diagnosis as long as you engage in x form of behaviour. We don’t do what we do because of what position a specific form of cognitive function is in, it’s rather that when we act in a certain way, the idea of cognitive functions can explain or put our actions in relationship to other people. This is also an important part of self-ownership and personal responsibility. Theories are simplified explanations of present day reality. Theories are not absolute or above reality. When a reality changes, our theories have to change or be flexible enough to account for that.

The MBTI should not become like astrology.

Fighting The Cognitive Function Soup

There’s bigger troubles with the eight function model too. It risks creating a cognitive function soup, in which anyone can possess any trait at any given time. Multiple personality theories, as I’d like to call them, work from the idea that we’re all personality types and we just switch between them from day to day. In particular, we switch from Introverted Feeling to Extroverted Intuition, to Introverted Sensing, and lastly to Extroverted Thinking, in the case of an INFP personality type. This is an idea I’ve found little empirical support of statistically in any form of personality test.

This idea cannot be measured, falsified, or defined in a clear way. Instead it becomes this explanation for what a person is – a person is everything, just depending on the situation. When studying personality, the most interesting thing to look at is a persons dominant strengths and weaknesses, and to consider what a person will typically do or act like. While a person can occassionally exhibit other traits or do other kinds of things, that doesn’t mean that they have multiple personality traits, it just means that their personality is slightly adaptable and malleable to the situation and to social expectations. If a person is more comfortable being introverted, it follows logically that if they’re extroverted, they may start to feel more uncomfortable over time.

If a person is more energized by intuitive conversations, it makes sense to assume she will become more drained more quickly by topics of a more sensory nature. These are falsifiable, testable, measurable statements, that can be supported by logical thought. But to say that an introverted intuitive, such as the INFJ, has demonic introverted sensing, is strange. First of all, the introverted intuitive should find introverted sensing comfortable, because it is introverted. Second of all, they should find sensing draining, because it is sensory. And so, they should find the function to be comfortable but boring, like something you do in autopilot. This might be information that often passes above your head, because you’re not interested in it, or you could call it “white noise”. A statement like this is far more accurate than to say that Introverted Sensing is your demon function. What does that even mean? Not to mention the unhealthy implications of arguing that everyone has a “demon” inside of them. Sure, that’s a nice excuse…

The Eight Function Model Simplified

The easiest solution is the best one. Instead of using crude and vague archetypes to define your relationship to each function you might want to consider

How comfortable you feel when introverting vs extroverting…

How much energy you get from intuitive vs sensory topics…

How much motivation you get from feeling vs thinking…

How much stress you get from judging vs perceiving…

And then you can logically draw the following conclusions:

Functions that require introversion vs extroversion may influence my comfort level

Functions that require intuition vs sensing may influence my energy and level of stimulation

Functions that require feeling vs thinking may influence my motivation

Functions that require judging vs perceiving may influence my stress levels

Ofcourse, this all depends on your level of preference and how much you’ve “trained” in using certain functions.

The goal is that the MBTI should be something you can use in your day to day life to understand your own actions and behaviours as well as it’s influence on your mood and flow.