Practical Function Meanings
Introversion versus Extroversion in functions - This describes whether the function is primarily outward-based or inward-based. Introverted functions tend to interact and receive input primarily from one’s internal world, and are inward-focused. Additionally, they tend to go very deep on a few specific issues. Extraverted functions tend to be outwardly focused and receive input from the external world. They tend to bounce around from topic to topic and have shallow understandings of many different things. In the general population, the split between those with dominant extraverted functions ranges from to 60/40 to 50/50 with a slight lead towards introverted functions depending on the source. At this time, I have not seen any information as to what the personality breakdowns are for nonbinary people.
Intuition versus Sensing - The words here are actually misleading. People with strong dominant intuition function tend to gather and process information in concepts. People with sensing tend to gather and process information in hard data and facts, using their five senses. For example, a sensory dominant person will see a picture of a red dog on a field and think: “This is a dog. He is on a field. The dog is red.” The intuitive dominants will think “what is the dog thinking? Why is it on the field? How is it feeling? Why is it red?”, and will try to come up with a narrative answering similar questions in their head. This is the only function pair where the entire population has a very significant bias towards one. Between two thirds and three quarters of all people are Sensors depending on the sources, with women having ever so slightly more Intuitives than men. Fun fact, some studies correlate N vs S with intelligence.
Thinking versus Feeling - This one is also strongly misunderstood. It does not mean “thinkers are reasonable while feelers are emotional”. There are plenty of highly emotional people with T in their four letter code. This is meant to break down how one makes their decisions. Thinkers predominantly make their decisions based on what is true and what is effective, things that are objective. Feelers predominantly make their decisions based on morals, values, right, and wrong, what is good or bad, things that are subjective. In a business, a stereotypical thinker would default to thinking what would make them the most money. A stereotypical feeler would default to pondering the ethical consequences of a business decision, and whether customers would like it. Thinking versus feeling is between a 40/60 and 50/50 split in the population with a bias towards feelers in the overall population. I personally believe the split would be closer to 50/50 in real life, but the way the tests ask the questions makes people biased towards feeling. However, gender-wise, it is the most stratified. Men are significantly more likely to be thinkers than women.