Carl Jung of Zurich was a contemporary and colleague of Freud. He had undertaken systematic investigations of the unconscious dynamics with the association test. He had given more attention to the question of personality type in the association test. Based on the typology of the personality. He had grouped them into two fundamental types.
The extrovert was very much interested in building a social relationship. While the introvert was found to be pre-occupied with his own inner world of fantasy and body activity and was relatively incapable of outgoing social interactions. His conception was further elaborated by going for a subdivision of the mental operation into four fundamental activities:
These four psychological functions of 'grouping personality' are very often used for gathering and evaluating information. According to Jung, individuals are strong either in 'sensation' or 'intuition' while gathering information, and while evaluating the information they are strong either in 'thinking' or 'feeling'.