The Full Form of ISTJ is‍ Introversion (I), Sensing (S), Thinking (T), Judgment (J).

ISTJ (introversion, sensing, thinking, judgment) is a four-letter code representing one of the 16 personality types found on the Myers-Briggs Personality Indicator (MBTI). People with an ISTJ personality type tend to be reserved, practical and quiet. They enjoy order and organization in all areas of their lives including their home, work, family, and projects. ISTJs value loyalty in themselves and others, and place an emphasis on traditions.

Key ISTJ Characteristics

• ISTJs are planners; they like to carefully plan things out well in advance. They enjoy an orderly life. They like things to be well-organized and pay a great deal of attention to detail. When things are in disarray, people with this personality type may find themselves unable to rest until they have set everything straight and the work has been completed.
• ISTJs are both responsible and realistic. They take a logical approach to achieving goals and completing projects and are able to work at a steady pace toward accomplishing these tasks. They are able to ignore distractions in order to focus on the task at hand and are often described as dependable and trustworthy.
• ISTJs also place a great deal of emphasis on traditions and laws. They prefer to follow rules and procedures that have previously been established. In some cases, ISTJs can seem rigid and unyielding in their desire to maintain structure.