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Free Personality Test

Take our Jungian Subtype Indicator (JSTI) personality test to discover your personality type and compare it to your MBTI® type.
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This free personality test expands upon the 16-type model popularised by the MBTI® and goes further to reveal your subtypes.

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Anyone can take this personality test and get their results for free.

This personality test was developed by PersonalityData.org using data from nearly 410,000 participants in a global study of personality types. It reports your type according to the traditional 16 type model (such as the Myers Briggs Type Indicator®) plus our Jungian Subtype Indicator (JSTI) model of personality.

All responses to this questionnaire are anonymous. By submitting answers to it you agree that your responses will be anonymously stored and processed by us for the purposes of personality research. Results will be published only in an anonymous aggregated form so that no one individual can be identified. For full details see our privacy notice.

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How is this test different to the 16 Type Model or MBTI®?

We have extended the 16 type model to include subtypes, which means 8 letters instead of 4 and a more detailed result.

The 16 type model of personality (the most popular of which is the Myers Briggs Type Indicator®) categorizes people according to 16 personality types, and reports them using a four-letter result. For example someone can be said to have an ESTP personality type, or INFP, and so on. The convenience of having 16 types and four letters offers a useful shorthand to understand different personality types, but it doesn't allow us to report variations within each type.

When we study the trait of extraversion for example (reported in the four-letter result as E), we see that there are in fact different versions of extraversion. The same E for extraversion would be applied equally to an outgoing gregarious personality as it would a confident assertive personality. So we introduce the concept of 'subtypes'. Back with the example of extraversion, we now have Eg for an extraverted-gregarious personality and Ea for an extraverted-assertive personality. When we extend this to each trait we end up with a personality type result of eight letters rather than four.

The nuance of personalty can get hidden within a single broad type. So we developed the concept of subtypes and created the JSTI.

Here we highlight the main differences between the traditional MBTI® and the JSTI model.

MBTI® model

16 personality types

The classic model of personality originally described by Carl Jung, and later developed by Myers and Briggs in their assessment tool the MBTI®.

  • 4 letters
  • 16 types
  • Results offer convenience in their four-letter notation.

JSTI model

16 personality types + 512 subtypes

The 16 type model has been adopted and expanded to account for the multidimensional nature of personality types.

  • 8 letters
  • 16 types and 512 subtypes
  • Results offer greater fidelity in their eight-letter notation.
quotation marks My INTP result makes more sense now. The introverted part I felt wasn't quite right but now I understand it as 'independent' that feels better
Jans Kopfzig, INTP

By incorporating multidimensional approach to the main four dichotomies, the JSTI model accounts for the unique behavioral styles that underpin a person's overall personality type. This grants the JSTI model a greater degree of depth, but retains the elegancy of the original 16 type model. It also explains how, in practice, two individuals who share the same personality type, can display quite different approaches in their behaviour and temperament.

However, the JSTI model was not designed to supersede the original 16 type model, or to make previous Myers-Briggs® tests obsolete. Instead, we see the JSTI model as a natural progression within the wider field of Jungian personality theory. As a result, we feel that the addition of personality subtypes compliments the existing theory and practice, providing additional information to test takers without removing from the elegance of the original model.

Therefore, we consider this JSTI assessment to be a highly effective tool for discovering your main Jungian type using the original 16 type model, while also providing additional information on your specific subtypes and behavioral style.

Why we Built the JSTI

Building on existing research we developed a Subtype extended model.

In recent years, research has shown that major personality types are actually multidimensional. For a practical example, consider extraversion. Some extraverts are more assertive and strong-willed, but others are more gregarious and cheerful. Both are “extraverts”, but they express their extraversion differently. To account for this, we have introduced subtypes to compliment a person's overall type, highlighting some the unique ways in which they express their particular type.

quotation marks We developed this Jungian subtype test because some traditional 16-type results don't always fit the person 100%.
Ellie Simmonds, MSc

Rather than merely identifying whether a person is an extravert or an introvert, the Jungian Subtype Type Indicator (JSTI) model explains what kind of extravert or introvert a person is, along with how that subtype influences their interpersonal style overall. This allows us to:

  • Provide a more descriptive account of a person's personality.
  • Account for differences within types, not just between types.
  • Incorporate recent advances in personality research.

The addition of subtypes does not remove from the original theory, and thus allows us to retain the elegance and simplicity of the traditional 16 personality type model. This ensures that our JSTI assessment is fully compatible with the results of traditional Myers Briggs Type Indicator® results, and the results can still be interpreted in line with traditional Jungian theory.

INTJ Example of a classic Jungian result

Example of a Subtype Extended Jungian result

Four letters gives 16 possible personality types, 8 letters give 512 possible combinations.

Each main type can have one of two subtypes, expressed as a lowercase letter. Subtypes add more detail to the result.

Letter Codes of the Jungian Subtype Indicator (JSTI)

Nomenclature of the subtypes associated with each primary personality type
This table shows how the popular 16-type model can be broken down further using a multidimensional approach.
Primary Type Subtype
Introverted (I) Independent (i)
Reflective (r)
extraverted (E) Gregarious (g)
Assertive (a)
Intuition (N) Creative (c)
Unorthodox (u)
Thinking (T) Logical (l)
Objective (o)
Feeling Warm (w)
Fair (f)
Sensing (S) Pragmatic (p)
Empirical (e)
Judgement (J) Thorough (t)
Methodical (m)
Perception (P) Versatile (v)
Spontaneous (s)

We see that each of the primary 16 personality types can be further divided into subtypes. If we take the extraverted type for example (expressed as E in the MBTI®), it's possible to identify two subtypes; Gregarious and Assertive. We can express these types as Eg and Ea, rather than a single E.

And so it continues with the other types. The single letter S could express more detail when expressed as Sp or Se for example.

letter i in grey circle for information point

Subtypes allow us greater personality profiling fidelity. For example the primary type 'S' can take the form 'Sp' or 'Se'. This is true for all primary types, and so we have the JSTI model.

With type theory, this sub-division of personality types can of course be extended. We could have sub-sub types, and sub-sub-sub types. But at some point we hit the limit of utility. Do several thousand 'types' make for convenient nomenclature? And eventually with multiple degrees of subtypes, we lose the concept of 'types' and arrive more at a 'scale'.

Myers Briggs® and the Jungian Model

The most popular Jungian type test is the Myers Briggs Type Indicator®

The Myers Briggs Type Indicator® is based on Jungian psychology and reports personality according to 16 different types.

Carl Jung (1875-1961) was a Swiss psychiatrist who proposed a theory of psychological types. In his book Psychological Types he speculated that people experience the world using four principal psychological functions: sensation; intuition; feeling; and thinking.

Jung's theory was taken and extended by Katharine Briggs and her daughter, Isabel Myers. They developed the Myers-Briggs Type Indicator® which classified people into 16 different types on the basis of four dichotomies: Introversion-extraversion, Sensing-Intuition, Thinking-Feeling, and Judging-Perceiving. The result can be conveniently expressed as four letters, for example an INTP type would be (I)ntrovered, I(N)tuitive, (T)hinking, and (P)erceiving.

Jungian personality theory, along with associated Myers-Briggs tests have attracted much academic interest since their inception. Large meta-analyses have thoroughly investigated the validity, reliability, and psychometric properties of popular Myers-Briggs tests, in line with good practice in the field of psychological testing. This means that Jungian types are some of the most thoroughly researched models of human personality, shaping the way we all think about human character and temperament.

Due to its simplicity and elegance, subsequent Myers-Briggs® tests have become extremely popular tools for personal and professional development. Thousands of training and development experts have undergone certification to administer Myers-Briggs tests and provide accompanying coaching services. These interventions have proven extremely useful when supporting personal and professional development, helping millions worldwide.

Myers-Briggs® tests have also been used effectively in the field of career coaching and occupation choice. A large body of research suggests that personality significantly influences career choice, and that certain personality types are more suited to some roles than others. Careers coaches, consultants, and advisers often use Myers-Briggs® tests to help people identify recommended career paths.

In more informal settings, understanding one's personality type also helps to more tactfully navigate the world itself. This grants individuals a significant degree of self-awareness, helping them to recognize their strengths and weaknesses from a behavioral perspective. These insights help in nearly every aspect of life, from managing relationships to handling stress to making big decisions. That's one reason why the Myers-Briggs Type Indicator® enjoys enduring popularity and will continue to be used for the foreseeable future.

Carl Jung in his seminal book Psychological Types posited that each person is dominant in either extraversion or introversion, and this 'general attitude type' will influence the rest of the person's personality. He said that in addition to the general attitude types there are 'functional types' such as thinking, feeling, sensing, and intuiting. Jung's theories on personality were relatively abstract compared to the more applied work done by Isobel Briggs Myers and her mother, Katherine Cook Briggs, when they built upon Jung's theories to create their 16-type Myers Briggs Type Indicator®.

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Jung originally posited eight personality types. Myers and Briggs expanded Jung's work to include 16 types. Now we have devised the JSTI model to extend this even further.

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Ellie Simmonds, MSc

University of Bath, Psychology

Ellie Simmonds, MSc in Psychology from University of Bath. Ellie is an associate lecturer on psychometric assessments and has extensive knowledge of the 16-type model.