The Myers Briggs Type Indicator (MBTI) is my most recent personal research obsession. The MBTI is based on the research of Carl G. Young, who introduced the theory of psychological types. Through a series of questions designed to identify a person's preferences, the MBTI test classifies them as one of sixteen psychological types. Each type is labelled with a combination of four letters, derived from a possible eight letters: E or I, S or N, T or F, J or...