Carl Jung coined “introvert” and “extrovert”

• The Swiss psychologist was born in 1875 and died in 1961. His father was a village pastor. His mother was a strong figure though she seems to have had a split personality.
• Jung's childhood was troubled and he developed a schizoid personality, becoming withdrawn and aloof. He thought he had two personalities and named them No. 1 and No. 2. Later he renamed his personalities ego and the self.

At university, Jung proved to be a brilliant student, graduating in medicine and natural science.

His doctorate was on "the psychology and pathology of so-called occult phenomena." Here he laid the foundations for two key ideas:

• The unconscious contains part-personalities, called complexes.
• Most of the work of personality development is done at the unconscious level.

• Make sure that you speak up when you have something important to say. 
• Take advantage of your ability to observe other people, the environment you’re in and the energy flow in the room.
• People will pay more attention to what you say when you do speak up.
• You probably have the ability to study things better and faster, so when you do say something make sure that it’s an eye-opener.
• People will trust you more and thus you’ll have access to more privileged information.