ENTP (By functions; Extroverted Intuition, Introverted Thinking, Extroverted Feeling and Introverted Sensing) is an abbreviation used in the publications of the Myers–Briggs Type Indicator (MBTI) to refer to one of sixteen personality types. The MBTI assessment was developed from the work of prominent psychiatrist Carl Jung in his book Psychological Types. Jung proposed a psychological typology based on the theories of cognitive functions that he developed through his clinical observations.