How the Myers-Briggs Type Indicator Works

Have you ever heard someone describe themselves as an INTJ or an ESTP and wondered what those cryptic-sounding letters could mean? What these people are referring to is their personality type based on the Myers-Briggs Type Indicator (MBTI).

The Myers-Briggs Personality Type Indicator is a self-report inventory designed to identify a person's personality type, strengths, and preferences. The questionnaire was developed by Isabel Myers and her mother Katherine Briggs based on their work with Carl Jung's theory of personality types. Today, the MBTI inventory is one of the world's most widely used psychological instruments.

This article discusses how the Myers-Briggs types were created, what the 16 different MBTI types are, and how this personality typing system works.

The Development of the Myers-Briggs Test

Both Myers and Briggs were fascinated by Jung's theory of psychological types and recognized that the theory could have real-world applications. During World War II, they began researching and developing an indicator that could be utilized to help understand individual differences.

Myers created the first pen-and-pencil version of the inventory during the 1940s, and the two women began testing the assessment on friends and family. They continued to fully develop the instrument over the next two decades.

An Overview of the Test

Based on the answers to the questions on the inventory, people are identified as having one of 16 personality types. The goal of the MBTI is to allow respondents to further explore and understand their own personalities including their likes, dislikes, strengths, weaknesses, possible career preferences, and compatibility with other people.

No one personality type is "best" or "better" than another. It isn't a tool designed to look for dysfunction or abnormality. Instead, its goal is simply to help you learn more about yourself. The questionnaire itself is made up of four different scales.

Extraversion (E) – Introversion (I)

The extraversion-introversion dichotomy was first explored by Jung in his theory of personality types as a way to describe how people respond and interact with the world around them. While these terms are familiar to most people, the way in which they are used in the MBTI differs somewhat from their popular usage.

Extraverts (also often spelled extroverts) are "outward-turning" and tend to be action-oriented, enjoy more frequent social interaction, and feel energized after spending time with other people. Introverts are "inward-turning" and tend to be thought-oriented, enjoy deep and meaningful social interactions, and feel recharged after spending time alone.

Sensing (S) – Intuition (N)

This scale involves looking at how people gather information from the world around them. Just like with extraversion and introversion, all people spend some time sensing and intuiting depending on the situation. According to the MBTI, people tend to be dominant in one area or the other.

People who prefer sensing tend to pay a great deal of attention to reality, particularly to what they can learn from their own senses. They tend to focus on facts and details and enjoy getting hands-on experience. Those who prefer intuition pay more attention to things like patterns and impressions. They enjoy thinking about possibilities, imagining the future, and abstract theories.

Thinking (T) – Feeling (F)

This scale focuses on how people make decisions based on the information that they gathered from their sensing or intuition functions. People who prefer thinking place a greater emphasis on facts and objective data.

They tend to be consistent, logical, and impersonal when weighing a decision. Those who prefer feeling are more likely to consider people and emotions when arriving at a conclusion.

Judging (J) – Perceiving (P)

The final scale involves how people tend to deal with the outside world. Those who lean toward judging prefer structure and firm decisions. People who lean toward perceiving are more open, flexible, and adaptable. These two tendencies interact with the other scales.

Remember, all people at least spend some time engaged in extraverted activities. The judging-perceiving scale helps describe whether you behave like an extravert when you are taking in new information (sensing and intuiting) or when you are making decisions (thinking and feeling).

The Myers Briggs Types

Each type is then listed by its four-letter code:

• ISTJ - The Inspector: Reserved and practical, they tend to be loyal, orderly, and traditional.
• ISTP - The Crafter: Highly independent, they enjoy new experiences that provide first-hand learning.
• ISFJ - The Protector: Warm-hearted and dedicated, they are always ready to protect the people they care about.
• ISFP - The Artist: Easy-going and flexible, they tend to be reserved and artistic.
• INFJ - The Advocate: Creative and analytical, they are considered one of the rarest Myers-Briggs types.
• INFP - The Mediator: Idealistic with high values, they strive to make the world a better place.
• INTJ - The Architect: High logical, they are both very creative and analytical.
• INTP - The Thinker: Quiet and introverted, they are known for having a rich inner world.
• ESTP - The Persuader: Out-going and dramatic, they enjoy spending time with others and focusing on the here-and-now.
• ESTJ - The Director: Assertive and rule-oriented, they have high principles and a tendency to take charge.
• ESFP - The Performer: Outgoing and spontaneous, they enjoy taking center stage.
• ESFJ - The Caregiver: Soft-hearted and outgoing, they tend to believe the best about other people.
• ENFP - The Champion: Charismatic and energetic, they enjoy situations where they can put their creativity to work. 
• ENFJ - The Giver: Loyal and sensitive, they are known for being understanding and generous.
• ENTP - The Debater: Highly inventive, they love being surrounded by ideas and tend to start many projects (but may struggle to finish them).
• ENTJ - The Commander: Outspoken and confident, they are great at making plans and organizing projects.

Taking the Myers-Briggs Type Indicator can provide a lot of insight into your personality, which is probably why the instrument has become so popular. Even without taking the formal questionnaire, you can probably immediately recognize some of these tendencies in yourself.

When working in group situations in school or at work, for example, recognizing your own strengths and understanding the strengths of others can be very helpful. When you are working toward completing a project with other members of a group, you might realize that certain members of the group are skilled and talented at performing particular actions. By recognizing these differences, the group can better assign tasks and work together on achieving their goals.

How MBTI Differs From Other Instruments

The MBTI is just one approach to personality typing. Personality typing refers to systems that categorize people based on their traits, tendencies, and other characteristics. Other popular types of personality tests include:

• The Enneagram
• The Five Love Languages
• The Big Five Personality Assessment
• The Workplace DISC Test
• Cattell's 16 Personality Factor Questionnaire

However, the Myers-Briggs types differ in some important ways. First, the MBTI is not really a "test." There are no right or wrong answers, and one type is not better than any other type. The purpose of the indicator is not to evaluate mental health or offer any type of diagnosis.

Also, unlike many other psychological evaluations, your results are not compared against any norms. Instead of looking at your score in comparison to other people's results, the instrument's goal is to simply offer further information about your unique personality.

Reliability and Validity

According to the Myers & Briggs Foundation, the MBTI meets accepted standards of reliability and validity. The official website for the test suggests that it has a 90% accuracy and test-retest reliability rating. One study found that while the scale showed strong internal consistency and test-retest reliability, variations were observed.

Other studies indicate that the reliability and validity of the instrument have not been adequately demonstrated. For example, some research suggests that around many people get differing results when they later retake the test and the test is not a good predictor of success in different careers.

The MBTI Today

Because the Myers-Briggs Personality Type Indicator is relatively easy to use, it has become one of the most popular psychological instruments currently in use today. Approximately two million U.S. adults complete the inventory each year.

The real MBTI must be administered by a trained and qualified practitioner that includes a follow-up of the results. Today, the questionnaire can be administered online via the instrument publisher, CPP, Inc., and includes receiving a professional interpretation of your results.

The current version of the Myers-Briggs Type Indicator includes 93 forced-choice questions in the North American version and 88 forced-choice questions in the European version. For each question, there are two different options from which the respondent must choose.