The Inspector
The ISTJ personality type is Introverted, Sensing, Thinking, and Judging, which means they are energized by quiet, independent work; pragmatic and detail oriented; logical; and skilled in organization and time-management. This combination of personality preferences produces people who value order, predictability, and routine. They are rule-followers who love the security that comes with knowing their place in the world. ISTJs are hard workers who are reliable, productive, and persistent. They appreciate the value of teamwork, but can be stubborn and struggle with change.

ISTJ Strengths

Perseverance. The ISTJ’s main and most admirable strength is perseverance; people of this type simply do not give up. This trait is advantageous to them and can be that which sets them apart in their careers. Their peers and competitors may possess greater skills, but few will match the ISTJ in dogged commitment. 

Planning. Because of the ISTJ’s Judging component, people of this type have a very clear command of time and priorities. They are quite skilled in planning, organizing, mapping out schedules and following agendas. They excel in time management, are punctual (and demand the same of others) and consistently meet their deadlines.

Detail orientation. ISTJs notice holes, gaps, errors that broader thinkers don’t. They like facts, details and numbers without the emotional or interpretive fluff. And they don’t take facts or information for granted, nor do they rely on it simply because someone else said so. They will check things out for themselves, meticulously.

Loyalty. ISTJs also have a natural instinct to protect and defend. Loyal, reliable and committed, these are people that can be depended on to guard everything from their families to our nation and these are responsibilities they proudly assume. To the institutions, organizations and people to which they are committed, they are unwavering in their service. 

ISTJ Weaknesses

Stubbornness. While ISTJs will be admired for their unwavering commitment to their duty and their sense of what is right and proper, the down side of this is that they can be stubborn, inflexible and dogmatic. They often believe there is one right way (theirs) and things must be done that way. Everything else is, by default, wrong.

Tactlessness.The ISTJ's fierce commitment to truth can also get them in trouble in interpersonal dealings. They tend to speak without much consideration for the feelings of others, thinking it is always more important to be truthful than to make people feel good. They may even experience internal conflict around trying to be tactful or diplomatic, sensing that they are not being completely honest, direct or straightforward.

Guilt. ISTJs take their work, their commitments and really all aspects of their lives quite seriously and they work hard to plan well and to make wise decisions. When things don’t go as planned, however, they may blame and beat themselves up about it, second guess their decisions and suffer guilt. They will have a hard time simply accepting that sometimes life doesn’t go as planned, and will feel a sense of personal failure and defeat. This can be a source of stress and on-going rumination.

Resistance to change. ISTJs, in their drive to uphold tradition and do things by the book, can be resistant to change and innovation. Suspicious of new advances and ways of doing things, not only do they experience strain when called upon to embrace change, they also often stifle creativity or fail to appreciate the benefit of approaching old problems in new ways. This can limit their potential and make them seem especially difficult and stodgy to their coworkers and subordinates.

ISTJ Growth and Development

In order to reach their full potential, ISTJs should:

Question the procedure. Just because it’s “the way it has always been done” doesn’t mean it is the best or the only way. ISTJs find comfort in coasting along following the manner in which things have always been done. However, this can mean missed opportunities for growth and development, both personally and professionally. ISTJs will benefit by a willingness to break out of the rut of tradition. It certainly isn’t necessary to reinvent the wheel or fix what isn’t broken, but being willing to at least examine and question is essential. 

Question the rules. Their refusal to break the rules, while admirable in some respects, can be unwise. Not all rules are just or efficient, and guidelines aren’t all carved in stone. While respect for authority and laws is generally a good thing, it is the duty of society to actively consider and question and, in doing so, serve as a check on authorities and their exercise of power.

Be spontaneous. ISTJs have a strong internal sense of time management. While this is one of the mechanisms that enables them to work hard and meet deadlines, it can also be imprisoning. The ISTJ should experiment with not setting a schedule for the day and letting life happen naturally, or try surprising his or her spouse with an unplanned date.

Get in touch with their feelings. ISTJs, in order to develop and become better-rounded individuals, may need to exert some effort in the emotions department. This will benefit them both in their personal and professional lives. Working to understand and express their own feelings will help to deepen and enliven their friendships and other primary relationships. 

Make time for leisure and personal development. ISTJs often become so laden with the duties of work, family and community that they devote little time to themselves. ISTJs, at the very least, need time to consider their lives and to think out the issues they face. They may tend to sideline hobbies because of more pressing responsibilities, but investing time in creative or social endeavors can help ISTJs to better fulfill the commitments they see before them and to relieve some of the pressure they experience.