When you’re browsing the internet reading about Myers-Briggs types, you’ll probably see people talking about “shadow functions.” This is a confusing concept, because people use the term “shadow” to refer to several different things related to personality types.

Inferior Function

Every type in the Myers-Briggs system has what we call a “function stack,” which describes how they interact with the outer world, process information, and make judgements. There are 8 possible functions (extroverted and introverted versions of Sensing, Intuition, Feeling, and Thinking), and each types uses four functions:

1. Primary Function
2. Auxiliary Function
3. Tertiary Function
4. Inferior Function

The primary and auxiliary functions are the ones we use most comfortably, the tertiary function develops as we mature, and the inferior function is largely outside our conscious control. Much of what makes one type distinct from another has to do with how we use our particular combination of four functions. I have a blog post explaining exactly how the four-letter type relates to function stacks. I won’t take the time to repeat that information here, but here are a couple examples:

• INFJ function stack: 1) Introverted Intuition, 2) Extroverted Feeling, 3) Introverted Thinking, 4) Extroverted Sensing.
• ESFP function stack: 1) Extroverted Sensing, 2) Introverted Feeling, 3) Extroverted Thinking, 4) Introverted Intuition.

Disclaimer: some of the links in this post are affiliate links. This means that, at no additional cost to you, I will receive a commission if you click on the link and make a purchase on that website.

Often when you’re reading about functions, the “shadow” is treated as just another name for the “inferior function.” I’ve done that myself in several posts. This is also what Isabel Briggs Meyers implies in her book Gifts Differing.* She describes the shadow as “the product of the least-developed part, which a person rejects and disowns. The shadow uses relatively childish and primitive kinds of judgements and perceptions, not intentionally in the service of conscious aims” (Meyers, 1995, p.84). She doesn’t spend much time talking about the shadow, but I get the sense reading her description that she thinks it can include both the tertiary and the inferior function if they are not well developed.

The Jungian Shadow

The best resource I’ve found for explaining the role of inferior functions is the book Was That Really Me? by Naomi L. Quenk. In her introductory chapters, she addresses the concept of the inferior function and the shadow.

Many people confuse the inferior function with the concept of the shadow and use the terms interchangeably (Quenk, 1982). In Jung’s system, the shadow is an archetype, one of our innate modes of responding to important universal psychological realities. The shadow includes those things people are unable or unwilling to acknowledge about themselves, such as undesirable character traits, weaknesses, fears, and lapses in morality, or desirable qualities such as intelligence, attractiveness, and leadership skills. The shadow is a key component of a person’s personal unconscious, a layer of the psyche that is more accessible than its much larger counterpart, the collective unconscious. (Quenk, 2002, Was That Really Me?* p.49)

Quenk draws a distinction between the inferior function as a sort of “doorway” to our unconscious, and the shadow. Our shadow informs our inferior functions, but is not the inferior function itself. Together, our inferior function and the shadow make up our personal unconscious (Jung, 1970, Mysterium coniunctionis).  This is made more confusing by the fact that Jung himself referred to the shadow as an “‘inferior’ personality.” He still draws a distinction between the fourth function and the shadow, though.

The individuation process is invariably started off by the patient’s becoming conscious of the shadow, a personality component usually with a negative sign. This ‘inferior’ personality is made up of everything that will not fit in with, and adapt to, the laws and regulations of conscious life. … Closer investigation shows that there is at least one function in it which ought to collaborate in orienting consciousness. Or rather, this function does collaborate, not for the benefit of conscious, purposive intentions, but in the interests of unconscious tendencies pursuing a different goal. It is this fourth, ‘inferior’ function which acts autonomously towards consciousness and cannot be harnessed to the latter’s intentions. (Jung, 1969, Psychology and Religion: West and East*

So, in Jungian psychology the shadow isn’t composed of any of our four functions. It is outside our conscious control, and shows up through our inferior function, which most of us don’t understand well or use effectively. It’s not necessarily bad but it often shows up as our “dark side,” the part of us that appears when we’re under stress. The shadow and inferior function are very much connected, but they are still different (even though we may use them interchangeably).

Four “Shadows”

One other explanation of shadow functions that you’ll occasionally see is a claim that each type uses all 8 functions. This theory describes the four functions that we just discussed as the “dominant processes” and the other 4 as the “shadow processes.” Using the same examples from before, it looks like this:

• INFJ
  • dominant processes: 1) Introverted Intuition, 2) Extroverted Feeling, 3) Introverted Thinking, 4) Extroverted Sensing.
  • Shadow processes: 1) Extroverted Intuition, 2) Introverted Feeling, 3) Extroverted Thinking, 4) Introverted Sensing.
• ESFP
  • dominant processes: 1) Extroverted Sensing, 2) Introverted Feeling, 3) Extroverted Thinking, 4) Introverted Intuition.
  • shadow processes: 1) Introverted Sensing, 2) Extroverted Feeling, 3) Introverted Thinking, 4) Extroverted Intuition.

It’s basically a way to quantify our unconscious and describe how it manifests through our inferior function. However, I don’t think Jung assigned “functions” within the shadow or thought the unconscious could be understood in that way, and I haven’t read support for this theory of 8 functions from psychologists discussing the MBTI.

Probably the best way to understand the idea of a “shadow” is to say that it is the part of our personal unconscious that we have the most limited access to. We experience our shadow through our inferior function, which is a part of the unconscious that we can access more easily because it is still on our function stack. Usually it shows up in a negative way under stress, but there’s also a good side to explore as well.

But the shadow is merely somewhat inferior, primitive, unadapted, and awkward; not wholly bad. It even contains childish or primitive qualities which would in a way vitalize and embellish human existence, but — convention forbids! (Jung, 1969, Psychology and Religion: West and East)

*indicates affiliate links