Dating all the way back to the late 1910s, the Myers-Briggs Type Indicator–more commonly referred to as MBTI–has been used as a personality tool to help identify and understand the human brain for over a century. Nowadays, it is used as a fun way to categorize one’s personality and outlook on the world. But how exactly does this function work?

A common question that has led to the research of MBTI is “Why are people different from each other?” This is the exact question that led Katherine Briggs and her daughter Isabel Myers to create the original MBTI test in 1919. After meeting her daughter’s husband, Briggs started to think about how each person has a different perception of life and function in different ways. This led her to start a literature review to understand these differences in a deeper way.

In 1921, Carl Jung published the book “Psychological Types”, a book about the functions people use in day-to-day life. Briggs read the English translation of the book and noticed many parallels between her and Jung’s work. From there, MBTI was developed and rapidly increased in popularity.

So what even is MBTI, and how does it work? While it may sound complicated at first, it’s actually much simpler than you may think.

At its root, MBTI consists of 16 different personality types that each person is born with. These types are different combinations of letters: Introversion vs. Extroversion (I vs. E), Sensing vs. iNtuition (S vs. N), Thinking vs. Feeling (T vs. F) and Perception vs. Judgment (P vs. J). One example of a type would be an INTP, who is introverted, intuitive, thinking and perceiving. The opposite of this type would be an ESFJ, who is extroverted, sensing, feeling and judging. Other type combinations include ISTP, ISFJ, ENTP, INFP, ESTJ, ISFP, ENFJ, ESFP, ISTJ, ENFP, INFJ and ESTP.

A common yet understandable misconception that many have is that you’re supposed to type yourself based on how you identify with each letter. For example, one might think they’re an INFP because they’re introverted, thoughtful, emotional, and laid-back- all of which fit the literal definition of an I, N, F and P, respectively. But it’s not quite as black-and-white as that; MBTI’s way of typing actually follows characteristics called ‘cognitive functions’.

There are eight different cognitive functions that you can use to type yourself; introverted sensing (Si), extroverted sensing (Se), introverted intuition (Ni), extroverted intuition (Ne), introverted feeling (Fi), extroverted feeling (Fe), introverted thinking (Ti) and extroverted thinking (Te). Each function has different attributes that go with them, such as Fe users being highly aware of the emotions of the people around them or Si users being sentimental about objects based on experiences they’ve had.

Each personality type has a different stack of four of these functions; a dominant function, auxiliary, tertiary and inferior function. An INFP’s cognitive function stack would be dominant Fi, auxiliary Ne, tertiary Si,and inferior Te, meaning their most used function is Fi and their least used function is Te.

Susan Storm, an author of the website Psychology Junkie, discusses in an interview how she uses the cognitive function “Ni” in day-to-day life.

“Introverted intuition, or Ni, allows me to forecast how things are likely to play out and helps me be strategic in what I’m doing,” Storm said. “Every decision I make is like a drop in a ripple effect, and Ni helps people be more aware of that effect.”

Naturally, the most popular way to figure out your type is by taking a quiz online. While websites like Sakinorva and Keys2Cognition are great for narrowing down your type, it’s best to research what each function means and decide your type based on that. More often than not, websites like 16personalities type based on letters and not functions, which leads to test-takers being mistyped.

So what makes this personality tool so popular? It’s interesting to learn about, yes, but can it really do anything for you in the real world? Is it even a reliable way of measuring personality? Well, in the original creation of MBTI, Myers believed that understanding each others’ differences could help humanity work together better.

MBTI is a great medium to understand people; whether that be obtaining a deeper understanding of yourself or finding a way to sympathize with those around you. Not to mention, many enthusiasts find it interesting to look at characters from TV shows, books, anime and video games who have the same personality types as them through websites like Personality Database.

“MBTI is not only a great way to understand yourself, but also see where other people are coming from,” Zaiden Dee, a freshman and MBTI enthusiast, said.

And while many believe that the reasoning behind MBTI isn’t concrete, there’s no denying that humans are creatures of pattern and are prone to follow certain rules of thinking. Either way, it’s an interesting idea to entertain, and there are plenty of uses for it in the real world. Freshman Kit Pozzi finds MBTI to be fascinating and somewhat representative of various individuals. 

“I think it’s interesting that [MBTI] can help you get to know what your strengths and weaknesses are, or what kind of relationships you thrive in.”