INTJ Functions: Primary and Secondary Cognitive Functions of the Scientist

If you’ve ever researched the Myers-Briggs Type Indicator (MBTI), you may already know that the INTJ personality type is among the rarest. Perhaps you’ve recently taken the test and been classified as an INTJ and want to learn more about what it means.

What are some cognitive functions and personality traits associated with INTJs? Read on to learn more about the INTJ “functional stack,” common INTJ traits and characteristics, and some top career paths and hobbies INTJs may pursue. 

INTJ Functional Stack

INTJ personality types are logical, rational, and concept-focused. According to the Myers-Briggs “functional stack” analysis, INTJs have introverted intuition for a dominant function, extroverted thinking as their auxiliary, introverted feeling as tertiary, and extroverted sensing as inferior. This results in a unique and valuable combination of rational and intuitive thinking.

The MBTI is based on theories that were first proposed by a psychiatrist from Switzerland, Dr. Carl Jung. Jung described eight primary functions, which, he claimed, form the foundations of all personalities. These functions are introversion vs. extroversion, sensation vs. intuition, thinking vs. feeling, and judgment vs. perception.

Jung believed that every personality type combines four functions, with one part being the dominant function and the others secondary. This combination of functions has come to be known as a functional stack.

Sounds a bit complicated, right? To better understand how it works in the real world, let’s look at the functional stack specific to INTJ personality types.

Dominant function: Introverted intuition

INTJs are introverted by nature. Like many with introverted personalities, INTJs need personal space to “recharge their batteries.” They enjoy spending time alone.

INTJs also rely more on intuition than sensation. This means that they often “just know” things or have ways of understanding that other personality types don’t understand. 

This intuition may seem like a sixth sense or a superpower to some. It allows them to understand and work through problems that might otherwise prove too formidable for their rational problem-solving skills to figure out.

Auxiliary function: Extroverted thinking

INTJs are great thinkers, planners, and analysts. While an INTJ’s intuition may lead to decision-making and problem-solving, logic and critical thinking skills support that intuition.

For example, an INTJ may have a “gut feeling” about something. Rather than relying on that intuition alone, the person will use their thinking skills to explore their gut feeling further, gathering logical information and ordering it systematically.

Tertiary function: Introverted feeling

INTJs are often mistaken as being cold and emotionless. This is not so much due to a lack of feeling–INTJs experience emotions like anyone else. They don’t always know how to express these emotions.

INTJs usually develop close emotional investments with a small number of people, such as family and a few close friends. They are often uninterested in social networking and making small talk, but they take their relationships seriously. This often makes them loyal and devoted spouses, parents, and friends.

Inferior function: Extroverted sensing

Though INTJs are known for processing information and absorbing new knowledge, they often struggle to remember essential details.

This is primarily due to their sensing function–they tend to sense the world around them and make sense of it intuitively rather than perceiving and observing the details. This tendency makes them seem insensitive to what’s happening around them and can often make them feel like outsiders.

INTJs typically share unique personality traits and characteristics given these four distinct functions. We’ll take a look at these defining qualities in the next section. 

Defining Qualities of an INTJ

INTJs are relatively rare, making up less than 5 percent of the world’s population. With that in mind, they tend to share some easily-identifiable traits. A few of these character qualities are as follows:


INTJs are some of the most goal-oriented people you’ll meet. They have big plans for making a difference in the world and love learning new things. These passions often combine and lead them to pursue meaningful careers and pastimes.

In addition, they prefer to work in an orderly, systematic fashion, which often means setting attainable goals to work toward something more significant.


INTJs are known for wanting to “fix things.” If they see a problem–whether in their own life or the lives of the people closest to them–they look for a solution to the problem.

This is part of what can make them seem emotionless and unfeeling. Conversely, it can make them valuable leaders and team members in a work environment because INTJs can often find solutions others might have overlooked.

Focused on the big picture

As mentioned, INTJs often struggle remembering simple details, such as a relative’s birthday or favorite restaurant. This isn’t because they are insensitive; it’s simply that they have a different way of looking at the world.

They often think about the future, analyze the “big picture” of their relationships, or contemplate a loved one’s interests and personality in a more general sense.

Thinking over feeling

This quality is another part of what makes INTJs seem emotionless. They are thinkers first and foremost, attempting to solve problems logically and focused more on getting results than making others feel good.

This doesn’t mean they don’t feel anything. It simply means they lead with their head and keep their emotions and feelings more private than most people.

Driven to succeed

INTJs will stop at nothing to succeed in the critical things to them. The idea of giving up rarely occurs to them. 

So now that you know a little about what makes an INTJ tick, let’s take a closer look at some specific strengths and weaknesses this personality type tends to possess.  

INTJ Strengths 

INTJs have many strengths that make them successful and even admired by other personality types. Though they are sometimes seen as awkward or quirky, anyone to appreciate an INTJ’s strengths is bound to notice their value.

Let’s take a look at a few of those strengths.


Because they are so driven to be successful, INTJs are some of the hardest-working people you’ll meet. The catch is that they must find the work meaningful in some way.

If an INTJ finds themselves stuck in a tedious job, they will still work hard to get it done, but they may not be personally invested. They will be on the lookout for a new job that is more fulfilling.

On the other hand, they may work exceptionally hard at something they consider essential even if they’re not getting paid for it. Whether it be a hobby, a volunteer position, or helping a friend, they will throw themselves into the work like nothing else matters.


INTJs’ minds often take them places where other personality types would never think to go. They may spend a significant amount of time analyzing the theme of a book or a movie, trying to understand the people around them, contemplating scientific theories and questions, and pondering the meaning of life.

Because of how their minds work, INTJs may be able to figure out problems that leave other personality types stumped. They may even be drawn toward engineering and computer programming because of the mental challenges and stimulation these fields provide.


INTJs can’t stand wasted time and effort. They will often come up with newer, better ways to do things. They don’t enjoy engaging in small talk or meaningless work because they consider these things a waste of time–a hindrance in their long-term path to success.

Since INTJs focus on the big picture, they often try to get from point A to point B as efficiently as possible. In some cases, this may be seen as a weakness, but it is a strength in terms of work and accomplishing their goals.


Though INTJs rarely enjoy social functions, they are fiercely loyal to the few friends and family members lucky to be in their inner circle. Though they may have trouble expressing their feelings, they love these few people more than life and would do anything to help them out of a challenging situation.

This trait is part of what makes INTJs such excellent spouses and parents.


INTJs do not like to depend on other people. They have their own “right way” of getting things done, so having to rely on someone else, especially if they do it the “wrong way,” can be highly frustrating for INTJs.

INTJs will work hard to be able to take care of themselves, even from a young age. For this reason, they may be seen as reliable, dependable, and self-sufficient.

The flip side is that they may not know when to ask for help, so it often takes a wise friend or relative to notice when an INTJ is in need.

Next, we’ll look at some of the common weaknesses of INTJ personality types. 

INTJ Weaknesses 

As we noted with the “independent” trait above, a person’s strengths can often become their weaknesses. The same can be said of INTJ personality types. Some of these common weaknesses include:

Prone to overworking

INTJs are such hardworking, dedicated individuals that they sometimes don’t know when to take a breather. And no matter how hard they work, they tend to feel that they aren’t living up to their goals or their standards of success. This may propel them to work even harder.

This trait may also present itself in their relationships with other people. When they are close to someone, they may try so hard to fix that person’s problems and help them with whatever they need that they begin to wear themselves out.


INTJs tend to envy. They may believe those around them achieve tremendous success or happiness than they do despite not working as hard. 

This envy probably stems from fatigue caused by working too hard, and over time it can become an INTJ’s constant companion.

INTJs can envy others’ successes, causing resentment to build up over time.

They don’t enjoy the feeling of envy, and most won’t talk about it, so they may try to rid themselves of the emotion by succeeding more. Unfortunately, no amount of success ever seems to satisfy them enough. Which leads us to our next trait. . . .


Because they try so hard to satisfy their need for success, many INTJs are perfectionists. They hold themselves and others to excessively high standards because their contentment and peace of mind demand it.

From another standpoint, they may desire perfection because of their need for order and efficiency.

Emotionally distant

INTJs, as we’ve discussed, care deeply for the people closest to them. But, as introverts, they also need their personal space. The general public may seem disinterested, bored, and difficult to relate to social situations.

This is mainly due to their significant effort into the people they love. INTJs do nothing halfway. They realize they can’t care deeply about everyone and have trouble connecting with people outside their circle. For this reason, they may be seen as snobbish, aloof, and emotionless.


Because they hold themselves and others to the highest standards, INTJs often appear overly critical. They may give well-meaning advice to a friend, but their difficulty in expressing emotion may make the advice seem cold and harsh.

Speaking of advice, INTJs don’t like it when people don’t listen to their advice. They may criticize a friend’s “bad choices” without showing empathy or allowing for personality differences, making them seem more critical than intended.

Of course, INTJs may also be overly critical of themselves if they don’t live up to their high standards. Being hard on themselves is part of what drives their success, but it can also become a hindrance if they push themselves too far or become depressed over their failures.

INTJ vs. INFJ: Key Differences

INTJs are often confused with a similar personality type, INFJ, but there are several key differences between the two. In short, INTJ is more driven by rationale and logic (or “thinking”), whereas INFJs are guided by the emotional needs of themselves and those around them (or “feeling”).

Both INTJs and INFJs are introverts, perfectionists, and driven to succeed. It’s the focus of their motivation that sets them apart. INTJs focus more on ideas, while INFJs concentrate more on people.

Here are some key personality traits brought on by this difference in motivation.

Make decisions based on logical, rational, and objective criteria.  Make decisions based on emotional criteria and feelings. 
May appear cold, emotionless, businesslike  May appear kind, caring, approachable 
May prioritize ideas and goals above personal relationships  May prioritize personal relationships above aspirations 
Will not compromise their beliefs to keep the peace  They will try to keep the peace and avoid conflict at the expense of defending their beliefs 
Mediocre communication skills  Excellent communication skills 

Top 5 Career Paths for INTJs 

As you might imagine, INTJs enjoy career paths that entail essential and meaningful work. They may also enjoy jobs that stimulate their mind, require problem-solving skills, and allow them to make a difference in the world.

With that in mind, let’s look at some top career paths an INTJ might pursue. 


INTJs often love science-related fields, especially those that allow them to take a hands-on approach. Careers in biology, astronomy, meteorology, and other areas will enable them to go all-in with a particular interest, learning more about whatever branch of science fascinates them the most.

Their fantastic reasoning and intuitive skills often allow them to make connections and draw conclusions that other people would overlook. Since they enjoy thinking about big ideas and concepts at length, they will likely enjoy the challenges a career in science would present.

Moreover, there are so many branches of science that the possibilities are nearly endless. Whether they would like to understand more about the animal kingdom, the human body, or quantum physics, they will likely be able to find a career specializing in that particular interest. 


Careers related to mathematics also tend to attract INTJs. Since their brains typically work logically and systematically, they often have no problem-solving complicated equations or determining probability.

Not all INTJs enjoy numbers, but for those who do, a career in mathematics makes sense. Working as a mathematician, accountant, auditor, or research analyst may bring an INTJ plenty of mentally stimulating challenges. If their mind is at work, especially if they’re interested in the work, they’ll likely find these jobs fulfilling and enjoyable.


INTJs may also find fulfillment in careers as physicians, nurses, surgeons, dentists, and audiologists. The healthcare field is diverse and has many jobs, many of which may appeal to an INTJ’s problem-solving skills, love of knowledge, and desire to do something meaningful.

Health and medical-related jobs also come in many different and particular jobs, allowing INTJs to specialize in the specific branch of medicine they find most interesting. If they’re interested in multiple areas, they may pursue one specialization at a time or not specialize at all. Healthcare careers give INTJs many different options.


Legal careers may interest INTJs for several reasons. Depending on the type of job, an INTJ may feel that they are making a difference or doing something important. They may enjoy the challenge of defending different types of clients, gathering and presenting evidence, or interpreting the law.

Their sharp minds and strong intuition make INTJs an excellent fit for careers in law. They often make brilliant lawyers, judges, investigators, paralegals, and legal writers.


Though INTJs may struggle in most people-oriented careers, education is slightly different because INTJs can teach whatever subject they’re most interested in. Please put them in a roomful of people at a party, they may want to escape but put them in a roomful of students learning about a particular field or topic, and the INTJ will come alive.

Of course, there are classes at different education levels on every subject imaginable, from world history to British literature to linguistics to culinary to STEM fields. Whatever particular area an INTJ enjoys most, they can pursue a teaching career to teach that one subject. 

Top 5 Hobbies INTJs Might Enjoy

So what about hobbies? What do INTJs like to do for fun?

Like all personality types, INTJs have many interests and things they enjoy doing. Generally, they enjoy learning all they can about their interests, creating things, and participating in activities that stimulate their minds and help them relax.

Let’s look more specifically at some hobbies INTJs might be drawn toward. 

Computer-Related Hobbies

These hobbies may include computer coding, programming, creating apps, and maybe even building their computer. INTJs often have a “sixth sense” when it comes to technology. Even if they don’t have a lot of formal training, they can usually figure out complex computer-related concepts relatively quickly.

Those who enjoy working with computers may develop enhanced skills simply by tinkering and picking up new skills on time. This, in turn, may lead to new career opportunities for those interested in pursuing them. 

Making Things

And by “things,” we mean anything and everything you could imagine, running the gamut from historically accurate armor pieces to complicated food creations. Some INTJs may enjoy arts and crafts, while others prefer building, cooking, sewing, stonework, or toy making.

Whatever their interests may be, INTJs often go all the way. Whether that means building a cottage using a particular architectural style or creating three-dimensional models of the universe, INTJs love a good challenge and take pride in their creations. 


Like many other personality types, INTJs enjoy video games–both playing their favorite games and creating new ones. Games that challenge their mind and cater to their specific interests often keep them entertained for hours.

The same is true of board games, card games, and other types of fun. While they don’t generally enjoy social activities, they might occasionally spend a whole evening playing Risk or Monopoly with a few close friends or relatives.

They may enjoy games like sudoku or crossword puzzles on their own, as these games present several enjoyable mental challenges. 

Martial Arts

There are many different kinds of martial arts to appeal to the interests of a wide variety of INTJs. Some enjoy more traditional martial arts, such as karate and taekwondo. Others prefer different disciplines, such as archery, boxing, and historical sword fighting. 

Martial arts may appeal to INTJs because of the physical and mental discipline involved. Martial arts present opportunities to learn something new or expand knowledge in a particular field, allowing them to break a sweat and work out physically. This mind and body exercise will likely provide interest and enjoyment to INTJs. 


INTJs love to learn and are often described as sponges soaking up knowledge. When they find a topic that interests them, they will learn all they can about it and may become experts on it simply through their research.

Whether that research involves reading, watching documentaries, taking classes, experimenting, or getting specialized training, INTJs love the mental challenges involved with learning.

They may put their newfound knowledge to work writing research papers, making educational videos, or talking about all they’ve learned with anyone who shares a common interest. Though some may call them “geeks” or “nerds,” INTJs have a great passion for learning, and yes, they will often research and learn new things as a hobby. 

Final Thoughts

And there you have it: INTJs have diverse, brilliant, fascinating personalities. In order of dominance, their primary functions are introverted intuition, extroverted thinking, introverted feeling, and extroverted sensing.

These combined functions often give INTJs an incredible mind that works through logical reasoning and intuitive observation. INTJs have a thirst for knowledge, especially of the topics that interest them, and they often have a knack for problem-solving.

Though they are often mistaken for emotionless, aloof, and “robotic,” INTJs have a deep capacity for loving and being loyal to those closest to them. They work hard to do what’s right for the people they care about, though they often struggle with expressing their emotions and accepting the feelings of others.

Overall, INTJs are fascinating and complicated individuals who cannot be easily summed up in only a few words. In this way, they are much like all the other personality types.