Model A

The leading function of the type. It defines a person's life program, worldview and system of values.

The first function is the core of the personality, its operating system. Through it a person perceives the world most adequately and confidently. This is the sphere where no proof is needed: the person simply knows how things work. They do not doubt their judgements here and defend their position with ease. The base function runs constantly and costs no energy — it is the natural way of engaging with reality. Its maximum, fourth dimension lets it take into account not only personal experience and accepted norms but also the unique situation and how events unfold over time. Under stress a person falls back on the first function — it serves as a reliable refuge where everything is clear and predictable.

The instrumental function. It serves to realise the program of the first function in the outside world.

The second function is the hands with which the first one creates. If the base sets the direction, the creative is responsible for ways and means. It is strong too, but works differently: more flexibly, in a searching mode, attentive to feedback from the world. Its three-dimensionality lets it tailor a solution to the specific situation rather than only to norms and past experience. A person varies techniques easily, experiments and finds unconventional solutions in this sphere. The creative function is a zone of confident creativity where one is ready to improvise. Mistakes are not frightening here, because there is inner support. Together with the base it forms the Ego block — the zone of maximum competence and independence.

The function of social adaptation. A person tries to look competent in this area while feeling unsure of their powers.

The third function is a zone of insecurity that a person tries to compensate. They understand that this sphere matters to society and try to meet expectations: they read up, copy the behaviour of successful people, rely on templates and prepared moves. Two-dimensionality means relying only on personal experience and accepted norms — any unexpected question or non-standard situation knocks them off balance. The role function works like a role: the person puts on a mask of competence, but doubt hides behind it. Criticism here is painful, because they know their weak spots themselves. With the right support, however, the role function can develop and grow steadily more confident.

The most vulnerable function. Information here is perceived painfully and causes discomfort.

The fourth function is the type's Achilles heel. A person is acutely aware of their weakness in this sphere and tries to avoid situations that demand it. One-dimensionality means relying only on personally lived experience — others' advice and general rules are barely absorbed here. Direct pressure on the vulnerable function provokes irritation, resentment or even aggression — the psyche's defensive reaction to a zone of vulnerability. The person does not merely handle these tasks poorly — engaging with them is physically unpleasant. Even constructive criticism lands like a blow. Yet the vulnerable function is also a point of growth: when a person admits the weakness and works on it consciously under the guidance of a more competent partner, the results can be significant. Together with the role function it forms the Superego block — the zone of social tension and adaptation.

The function through which a person is most open to suggestion and needs outside help.

The fifth function is the most open to outside influence. It is weak and unconscious: a person does not track its work and cannot lean on it confidently, so they trustingly accept information from outside without critical analysis. One-dimensionality leaves it only scant personal experience — which is exactly why others' hints are received gratefully and unchecked. The person expects a partner or their circle to take care of this aspect, and is drawn to people who are strong in it. When help arrives in time and tactfully, they feel comfort and relaxation. When it does not, a vague anxiety builds whose source they usually cannot identify. It is through the suggestive function that a dual “feeds” their partner with their base function.

The function that switches on in response to outside support and encouragement.

The sixth function wakes up when someone winds it up. It is weak and works from another's example: a person needs outside reference points, approval and a model to engage in this sphere. Two-dimensionality lets it absorb accepted norms, but without external support the activity quickly fades — keeping a high level here on one's own is exhausting. The person does not initiate actions on the sixth function, but responds willingly when a partner gives the signal, and blossoms when praised on this aspect. It resembles a dance: one leads, the other follows. Together with the suggestive it forms the Superid block — the “childlike” zone of the psyche where a person looks to their surroundings for help, care and support.

A strong background filter function. It tracks the situation and sets limits, but the person dislikes working with it for long.

The seventh function is strong but unconscious: it works like a background detector, without an act of will. A person sees perfectly how others express themselves in this sphere and instantly spots errors and inconsistencies — three-dimensionality allows judging the situation as a whole, not only by the norms. Yet engaging this function actively and at length does not interest them: it is used in short, precise pulses — to check someone, to warn, to draw a boundary. Hence the name restrictive: with it a person protects themselves and those close to them, cutting off dangerous or pointless options. It is like an experienced critic in the stalls: he does not go on stage himself, but is the first to see an actor's slip.

A strong function of background action. It works automatically and powerfully, without control and without seeking recognition.

The eighth function is comparable in strength to the base (both are four-dimensional) but works without the participation of consciousness. A person acts in this sphere easily and effectively without noticing it: others see powerful, confident work, while the person is sincerely surprised when it is pointed out — to them it is simply obvious and nothing to be proud of. The demonstrative function needs neither awareness nor recognition — it just does. With it a person silently helps those close to them: they do not discuss the problem, they take it and solve it. Together with the restrictive it forms the Id block — the zone of strong unconscious automatisms, the psyche's working hands that act without words or declarations.