The book explains the many practical applications of this typological model [1] using four categories of psychological type differences — Extraversion / Introversion; Sensing / Intuition; Thinking / Feeling; Judging / Perceiving.
The book also suggests how different combinations of these characteristics tend to influence the ways people perceive the world and how they both respond to and interact with it.
[1] The late Isabel Briggs Myers devoted her life to the observation, study and measurement of personality and psychological type indicator theory.
With her mother, Katharine Cook Briggs, she developed the Myers–Briggs Type Indicator personality inventory.
Her son, Peter B. Myers, continues research work on the development and application of personality type.