ISTP

ISTP (Introversion, Sensing, Thinking, Perceiving) is an acronym used in the Myers-Briggs Type Indicator (MBTI) publications to refer to one of the sixteen personality types. The MBTI assessment was developed from the work of prominent psychiatrist Carl G. Jung in his book Psychological Types, which proposed a psychological typology based on his theories of cognitive functions.

From Jung's work, others developed psychological typologies. Well-known personality tests are the MBTI assessment, developed by Isabel Briggs Myers and Katharine Cook Briggs, and the Keirsey Temperament Sorter, developed by David Keirsey. Keirsey referred to ISTPs as Crafters, one of the four types belonging to the temperament he called the Artisan.

The MBTI instrument

 * I - Introversion preferred to Extraversion
 * S - Sensing preferred to iNtuition
 * T - Thinking preferred to Feeling
 * P - Perceiving preferred to Judging

Myers-Briggs description
According to Myers-Briggs, ISTPs excel at analyzing situations to reach the heart of a problem so that they can swiftly implement a functional repair, making them ideally suited to the field of engineering. Naturally quiet people, they are interested in understanding how systems operate, focusing on efficient operation and structure. They are open to new information and approaches. But contrary to their seemingly detached natures, ISTPs are often capable of humorously insightful observations about the world around them, and can be closet daredevils who gravitate toward fast-moving or risky hobbies (such as bungee jumping, hang gliding, racing, motorcycling, and parachuting), recreational sports (such as downhill skiing, ice hockey, and scuba diving), and careers (such as aviation and firefighting).

Keirsey description
According to Keirsey, Crafter Artisans are masters at using tools of every type—artistic, technological, martial. Although they are introverts, they are authoritarian in their interactions with others and can be forceful at influencing people. They focus on accomplishing tasks efficiently and skillfully.

To master the tool of their interest, ISTPs require a certain degree of seclusion in which to practice. The result is often a virtuosity that other types find difficult to match.

Cognitive functions

 * Dominant Introverted Thinking (Ti) - The ISTP lives a world of logic, basing decisions on logic. They process information from their auxiliary function to create strategies for action at a moment's notice. They love to examine complicated systems.
 * Auxiliary Extraverted Sensing (Se) - This function gives ISTPs an element of spontaneity, driving them to embrace opportunities to plunge headfirst into experiences. It also gives them a keen insight into situations similar to that of the ISTJ. Their occasionally tunnel-visioned curiosity for the world around them gives them a "leap before you look" tendency. They are notorious for taking apart devices to "see what makes them tick", before considering whether they can put them back together.
 * Tertiary Introverted iNtuition (Ni) - Never as open in their theorizing as the INTP, the ISTP prefers to keep themselves grounded in the situation at hand, using their intuition to visualize components and concepts that they cannot see and touch firsthand, such as the wiring in a circuit board.
 * Inferior Extraverted Feeling (Fe) - This is the weak point of ISTPs and it may lead them to interpret criticisms of their ideas as criticisms of their competence. Although ISTPs strive to follow the edicts of logic, their inferior function can lead them to illogically and stubbornly cling to their own ideas even when proven wrong.