The Myers-Briggs is a standard indicator of a person's tendencies using four basic scales with opposite poles. The four scales are: (1) Extraversion/Introversion, (2) Sensing/Intuition, (3) Thinking/Feeling, and (4) Judging/Perceptive.

“The various combinations of these preferences result in 16 personality types,” says Consulting Psychologists Press, Inc., which owns the rights to the instrument. Types are typically denoted by four letters--for example, INTJ (Introversion, Intuition with Thinking and Judging)--to represent one’s tendencies on the four scales.

According to some sources, the MBTI© is “ the most widely used personality inventory in history.” According to the Center for Applications of Psychological Type, approximately 2,000,000 people a year take the MBTI. The tool claims claims that it “helps you improve work and personal relationships, increase productivity, and identify leadership and interpersonal communication preferences for clients.”

Many schools use the MBTI© in career counseling. A profile for each of the sixteen types has been developed. Each profile consists of a list of “characteristics frequently associated with your type,” according to CPP.