This personality is the Roughneck. With Introverted Sensing (Si) as their primary function, otherwise known as subjective sensation, and Extroverted Thinking (Te) as their secondary function, otherwise known as objective logic, ISTJs are one of the toughest of the types. If there is any type more apt to the challenge, this is the type to brandish the stars and bars, smith their own weapons in their basements, and then go wrestle bears shortly afterward.

With Si as their primary function, they like to maintain an aesthetic homeostasis at all times. They are nature lovers, but also enjoy a well decorated home. They can be very slow and easy going, up until its time to mobilize. With such a strong attunement to subjective sensation, they can ignore objective sensation outright. What this means, is that when an ISTJ is in pain, they can override their objective sensation by focusing entirely on their subjective internal state. In other words, they can almost deny that any pain exists, if need be. Not only that, but ISTJs are very focused on their world and making sure it is tranquil. With Fi as their third function, they are prone to a recursive internal state of reflection and nostalgia. Older ISTJs may identify with having a house that looks like a museum of their life.

It is not uncommon for some ISTJs to be confused as ESTPs, because they share the same functions with opposing introversion/extroversion, and have a live for the moment attitude. The difference is their orientation to the senses, which is internal, as opposed to external and objective.

With Te as their secondary function, ISTJs focus on what is objective and real. They do not waste time with conjecture or theory, only results. Physically, an ISTJ with a heavy focus on Te, may have a much more alert and aggressive facial expression or glare. With such a heavy focus on the concrete and real, the unreal and abstract can be a complete mistery to them, sometimes causing paranoia from the threats that more intuitive personalities pose. They focus primarily on indisputable facts and experience. If their Te is not used enough, they can focus too much on the objectivity of others and never apply it to themselves. As such, they may often times view their ethical opinions as logical conclusions, when they are only subjective opinions.

Expression of love and affection is not something ISTJs do very often. When they do, it is often expressed through actions of service, or touch. Many ISTJs can become very uncomfortable with personalities who expect them to be warm, lively and excitable. This can grate on the ISTJ. In times of stress, ISTJs may lash out seemingly unpredictably from their usual easy going state, and they can grow hostile with anyone who challenges the current group dynamic, or they consider to be incompetent. ISTJs often times have difficulty showing affection for prolonged periods of time, and also seem to have a strange fascination with pets and animals.

Deep down inside of every ISTJ is an ENFP. As such, they can sometimes reveal their more quirky and impractical side. One example of this is Troy Hurtubise, the inventor of the “Ursus Bear Suit.”

The ISTJ world is one of tranquility and stability, but if left too long, they can grow depressed as their Si takes over and they are lost in a recursive internal state. As such, they need a parter who challenges them to leave their mind and explore the world in a way that isn’t threatening to their life balance. The best match for the ISTJ is someone with a strong sense of self that encourages the ISTJ to open up or appreciate another person in a way that is comfortable to them. They also look for someone who will serve as the perfect student for their lessons and experiences. The ISTJs best match is the ENFP.

Common Identities: The Roughneck, The Duty Fulfiller, The Soldier, The Aesthetic, The Museum, The Lone Wolf, The Loyalist, The Moral Aggressor, The Ethical debater, The Banker, The Mechanic, The Nomad, The Teacher, The Wise Sage.

Recommended Careers: Hard Labor, Banking, Inspector, Military, Construction, Fitness Trainer, Nutritionist, Mechanic, Historian, Teacher.

Commonly Mistype as: ISTP, ESTP, ESTJ, INTJ.

Common Enneagram Typings: 1 5 6 8

Famous ISTJs include: Tommy Lee Jones, Josh Brolin, Troy Hurtubise, Famke Janssen, Christopher Lee, Ian McKellan, Michael Pachter, Silvester Stallone, Jean Claude Van Damme, Paul Reisner, Goldie Hawn, Harrison Ford, Kristen Stewart, Jenna Jameson.

Fictional ISTJs include: Gandalf (Lord of the rings), Eeyor (Winnie The Pooh), Sarabi (The Lion King)