Socionics is a branch of psychology that is based on Carl Jung's work on Psychological Types, Freud's theory of the conscious and subconscious, and Antoni Kepinski's theory of information metabolism. It was founded mainly by the Lithuanian researcher Aušra Augustinaviciute in the 1970s and is evolving rapidly.

Socionics is based upon the idea that a person's character acts like a set of blocks called "psychological functions". Different ways of combining and chaining these functions result in different ways of accepting and producing information, which in turn results in different behavior patterns and thus different character types. Socionics also includes an intertype relations theory, based on the interaction of these functions between personalities.

Psychlogical functions - According to Carl Jung there are four psychological functions:

  1. Sensation
  2. Thinking
  3. Feeling
  4. Intuition

Feeling and thinking are rational (i.e. ordering functions) and sensation and intuition are irrartional (i.e. percieving) functions. Each function can be introverted or extroverted, which gives as a result 8 different psychological functions.