Myers-Briggs Type Indicator (MBTI) is a personality indicator designed to assist individuals to identify their significant personal preferences. Katharine Cook Briggs and her daughter Isabel Briggs Myers developed the Indicator during World War II, and its criteria follow from Carl Jung's theories in his work Psychological Types. The Myers-Briggs Type Indicator is the most widely used psychological instrument to indicate personality type. It is used to improve workplace performance by helping employees to break down barriers that can prevent effective communication, decision-making and team contribution.

Fundamental to the Myers-Briggs Type Indicator is the concept of Psychological Type. In a similar way to left- or right- handedness, the principle is that individuals also find certain ways of thinking and acting easier than others. The MBTI endeavors to sort some of these psychological opposites into four opposite pairs, or dichotomies, with a resulting sixteen possible combinations. None of these combinations is 'better' or 'worse', however Briggs and Myers recognized that everyone has an overall combination which is most comfortable for them: in the same way as writing with the left hand is hard work for a right-hander, so people tend to find using their opposite psychological preference more difficult, even if they can become more proficient (and therefore behaviorally flexible) with practice and development.