A dichotomy is a binary trait that divides phenomena into one of two opposite categories. Dichotomies are a necessary attribute of any typology. For example, Jung’s Typology divides people using four dichotomies: extraverted / introverted, rational / irrational, thinking / feeling, and intuitive / sensing. There are 16 possible combinations of the axes or poles of these four dichotomies.

Dichotomies in Jung’s Typology and in socionics exist side by side with functional models and are generally recognized to be a result of the positioning of various information elements in different functions of the model, rather than an independent property. For example, rationality/irrationality and extroversion/introversion dichotomies are defined by the information element positioned in first function of the type, while sensing/intuition and ethics/logic dichotomies are determined by the identity of information elements found in the ego block of the type. Dichotomies are fundamentally built into the rules of information element and function positioning in model of the TIMs.

Dichotomies are applied in treatment of other key aspects of socionics, such as intertype relations. These influences are perhaps harder to understand, since intertype relations theory was originally built upon the interaction of IM elements rather than dichotomies. However, several contemporary socionists, such as V. Stratievskaya and V. Gulenko, apply both Jungian and Reinin dichotomies to further explain the dynamics and properties of various intertype relations, as well as expand upon such subjects in socionics as characterization of quadra and quadra progression. Smilexian socionics is another attempt to achieve descriptions that factor in dichotomous influences.

Compared to the Myers-Briggs Typology, socionics employs quite a few additional dichotomies. Some socionists, like Viktor Gulenko, integrate into their systems dichotomies from outside socionics, especially to characterize intratype differences.

Formal Properties

All dichotomies are:

  • Jointly Exhaustive - Each dichotomy can categorize all elements in its group.

  • Mutually Exclusive - An element cannot fit both traits at the same time.

Dichotomies in socionics have two additional properties:

  • Central - Pairs of traits have the same number of elements.

  • Symmetric - Traits can be divided evenly in half by other related dichotomies

The only exception to the last two rules is the identity dichotomy, a mathematically necessary dichotomy for Reinin’s style of structure.

Type dichotomies

In socionics, each type is characterized by one trait (or pole) of each of the following 15 dichotomies. The first four are referred to as the Jungian foundation, and the other 11 are referred to as Reinin dichotomies, named after the socionist Grigoriy Reinin, who mathematically demonstrated the existence of a total of 15 orthogonal dichotomies. Technically speaking, the Jungian foundation is a subset of the Reinin dichotomies, although they are given much more attention in socionics and are not questioned.

Each Reinin dichotomy is either dependent or independent of (and hence “orthogonal to”) each of the dichotomies in the Jungian foundation. Its “tier” is the number that it is dependent on. This means that the number of dichotomies in the nth tier must be 4Cn, where C denotes combination. The idea of grouping dichotomies into “tiers” seems to have come from Dmitriy Lytov, and not G. Reinin himself.

In 2003, a socionics research group at the laboratory of interdisciplinary researches of The Institute of Biology and Psychology of Humans (IBPCH) has conducted a study which attempted to test for, characterize and substantially augment what is known about several Reinin groups, presented actual statements made by research subjects, as well as advance and test a number of hypotheses. Their publication can be found here: Reinin Dichotomies: Study Results.

Jungian foundation (or first-tier dichotomies)

This first grouping of dichotomies, the Jungian foundation, is used universally among socionists. The rest are somewhat controversial, but popular among many socionists. To understand where they came from, read about the Reinin dichotomies.

Second-tier dichotomies

Third-tier dichotomies

Fourth-tier dichotomies

Function dichotomies

Functions can be categorized by using seven Function dichotomies:

Element dichotomies

Information elements can be categorized by using seven element dichotomies:

  • Extroverted / Introverted

  • Irrational / Rational

  • Static / Dynamic

  • External / Internal

  • Abstract / Involved

  • Alpha / Gamma

  • Beta / Delta