It’s hard to make generalizations about introverts. By definition, introverts are more drawn inward toward reflection and less drawn outward toward engaging with the world of experience. And this means that usually we are less social, athletic, and energetic but more sensitive, cautious, and thoughtful. But there’s a wide variety of ways to be introverted. People’s personalities differ a lot, and introversion manifests in different ways because of this.
For this post, though, I’m going to focus on inborn qualities. Carl Jung, the founding father of introverts and extraverts, wrote that there are four general ways of being introverted. They have to do with which mental function we naturally develop early in life. A mental function is a kind of mental activity that has a certain way of engaging the mind. It can take one of four forms: thinking, feeling, sensation, and intuition.
Thinking: Arranging ideas in a logical framework.
Feeling: Judging whether something is good, right, valuable, or desirable.
Sensation: Any perception generated by the senses.
Intuition: Unconscious insights about connections that our minds perceive.
Each of these functions can be directed outward at the world of experience (extraverted) or inward at our own selves (introverted). Because this blog is about helping us understand introverts better, I’ll spend this post describing the introverted functions, although I’ll talk about the extraverted ones later. Also, remember that both introverts and extraverts use introverted functions. Even if they are stronger in introverts, an extravert will have an introverted side too, so extraverts reading this may want to think about how they engage with their own selves so they can open up their introverted side.
Here are the four introverted functions and how they work (drawn from Jung and Nardi). Remember that this all happens in the mind and doesn’t need to be communicated. In other words, people who use these functions do this in their head without any need to write things down or talk them out.
Introverted Thinking (Ti)
People who use Ti live in a world where everything has a cause and an effect, and they can always come up with an explanation. They are good at deliberately arranging ideas in their minds and applying their logical powers to problems and debates. They might be engineers who can mentally rotate a diagram of a machine in their heads. Or they might be public speakers who can think of the best ways to arrange words to make a point or devise a comeback. They may be able to do math problems, come up with business strategies, or work with scientific theories, all in their head.
Ti is the typical way of being introverted, or being in your head. That's why we call it "thinking." As a rough guess from my observations and research, probably around 60% of people mainly use Ti, including over 80% of men and nearly half of women. This makes it the normal way people think of mental activity.
Those who use Ti often develop these abilities:
Introverted Feeling (Fi)
People who use Fi live in a world where everything has value and uniqueness. They just know when something is right or wrong, if they like or dislike something, or if doing something is true to their authentic selves or not. They may become devoted parents, focusing all of their attention and energy on their children. Or they may volunteer at an animal shelter or work with children with special needs. They may deeply understand others’ feelings, see potential where others don’t, and find the greatest joy in becoming their ideal selves.
Probably around 15–20% of people mainly use Fi, including around 30% of women.
Those who use Fi often develop these abilities or tendencies:
Introverted Sensing (Si)
People who use Si live in a world where every experience has meaning. Each new experience is compared with older ones, and each memory is enhanced when reexamined. They have a knack for remembering forgotten facts about important people, places, or groups in their lives, and love studying facts and history about these things. They have fond memories of the familiar, at least if they had a good experience with it, and will look at old pictures, visit old friends, and stay in familiar places. They are often found working at the same place for many years or being part of churches or other groups that they enjoyed as children.
Probably around 15–20% of people mainly use Si, with about the same number of men and women.
Those who use Si often have the following qualities:
Introverted Intuition (Ni)
People who use Ni live in their minds. The world around them appears blurry, not quite real, while the ideas in their minds are vibrant and alive. People, places, objects, and events in the world aren’t as interesting or engaging, unless they generate new ideas in their minds. They will often study one or many subjects in great depth, absorbing ideas that will combine in their minds into holistic insights about the world. They see law-like patterns in the world around them, so the world looks less like a collection of objects and more like a series of patterns that are all interconnected.
Probably less than 5% of people mainly use Ni, with about the same number of men and women.
Those who use Ni often develop the following qualities:
Do you notice any of these tendencies in yourself? Everyone should use at least one introverted function at least some of the time. And remember, introverted functions naturally happen in your head, not externally. Think about what happens most naturally in your mind and you may be on track to figuring out which introverted function you use the most.
In a future post, I’ll describe the four extraverted versions of these functions. I’ll also describe how these functions produce eight different types of introverts and extraverts.
Carl Jung - Psychological Types
Dario Nardi - The Neuroscience of Personality: Brain Savvy Insights for All Types of People
Note: The designations of Ti/Fi/Si/Ni for the introverted functions is not Jung's, but a shorthand developed by others later. I am unsure who to attribute, since I can't find the source, but it is not me. It is, however, widely used among those interested in Jung's types.
I’m Harrison Paul, the Introvert Philosopher. I hold an MA in Philosophy from San Francisco State University and wrote my thesis on using moral education in schools to resist the influence of advertising on politics. I am the author of five-book introvert epic fantasy series Kaybree versus the Angels. I am also actively seeking publication for my nonfiction book The Quiet Minority: Why Introverts are Oppressed and How We Can Stop It and the Aurora Lightwalker series of far-future YA introvert novels.