The Myers-Briggs Types Indicator (MBTI) is an introspective, self-reported questionnaire that can indicate different psychological preferences regarding how people perceive the world and how they make decisions. The test seeks to assign four categories: introversion or extroversion, sensing or intuition, thinking or feeling, and judgment or perception. The first English letter of each category is taken to form a four-letter test result, such as “I. S. T. J.”

 The MBTI test is very popular today and it is used by nearly two million people in the United States each year.Most of the research supporting the validity of the Myers-Briggs Type Indicator was conducted by the Center for Applications of Psychological Type, an organization managed by the Myers-Briggs Foundation, and was published in the Center's Journal of Psychological Type, raising some questions about independence, bias, and conflicts of interest.Some independent sources have described this test as "nonsense", adding that it is "barely superior to the Chinese fortune cookie",and also stating that it is "quite nonsense" and describing it as "a fad that refuses to die out". 

 The Myers-Briggs Type Indicator has similarities to some psychological theories, but it is classified as pseudoscience, particularly because of its supposed predictive powers. This index shows several scientific (psychological) shortcomings, including its poor validity (i.e., it does not measure what it claims to measure, and lacks predictive power and generalizable items). Poor reliability (i.e., it gives different results for the same person on different occasions), and its cross-group measurement is not dependent on individual results (as a connection between contradictory traits is observed), and it lacks comprehensiveness (because it does not include neuroticism).

 There is a certain correlation between the four scales used in the Myers-Briggs Type Indicator and four of the five personality elements that are generally considered to be the most widely accepted.