DiSC®, DISC, and D.I.S.C.; Why are there so many different assessments?

Adam Stamm
7 min readSep 27, 2022


DISC assessments are completed by millions of people each year.

Many learners can’t believe a simple assessment can produce a report that describes them so well. It helps that the insights from this model are easy to understand. The model allows leaders, individuals, and organizations to improve interpersonal relationships and how they communicate because the model is easy to remember and use.

Unfortunately, it can be very confusing to navigate all of the different DISC assessments that are available. Here is a quick sampling of a few of them: Everything DiSC®, DISC Basic, Extended DISC, Taking Flight with DISC, Crystal Knows DISC, and DiSC Classic®.

How can a simple model become so confusing to purchase?

In this article, I will review:

  • Who created the D. I. S. C. Model?
  • Why there so many different DISC assessments

This article won’t try to sell you on one assessment over the other. Instead, I hope it’s useful for you to navigate through all of the different versions that you can find with a quick Google search of the term ‘disc assessment.’

William Moulton Marston: The Theorizor of D. I. S. C

The story of DISC begins with a man named William Moulton Marston and his book, Emotions of Normal People.

Marston was involved in many projects that interested him deeply in understanding people.

Marston was a Harvard-trained physiological psychologist, a subdivision of behavioral neuroscience. However, after becoming a psychologist, Marston trained and studied at Harvard to become a lawyer.

Marston was convinced he could develop a tool to determine someone’s innocence or guilt. Marston saw that the field of psychology could help transform the court system, and for most of his life, Marston would continue trying to modify and improve his invention: the lie detector.

Additionally, Marston was deeply interested in storytelling. In 1916, while a student at Harvard, Marston entered a contest that sought to find the best movie scenario. Marston’s script won and premiered next to Charlie Chapman’s work.

In 1928, also the year he published Emotions of Normal People, Marston created a public research project to test if he could identify a woman’s love interests by having them watch a scene of “Flesh and the Devil” and monitoring their blood pressure.

Marston’s ‘Love Meter’ and Lie Detector never panned out. He died before his model was turned into an assessment. However, Marston did have one major success: comic books. Marston is the writer and creator of the original Wonder Woman series.

It is with this background that Marston published his book that would be used to classify the model we now know as DISC.

Emotions of Normal People

In the Emotions of Normal People, Marston outlined how you could better identify why a person behaves in a particular and predictable way based on observable emotional patterns. Marston saw that our experiences shaped our behaviors.

Marston theorized that the expressions of our emotions (behaviors) could be categorized into four types. His insights eventually became the core model of D. I. S. C.

The emotions (behaviors) Marston identified were:

  • Dominance (D)
  • Inducement (I)
  • Submission (S)
  • Compliant (C)
Marston’s model focused on understanding a person’s behavior based on if they felt power over their environment.

Marston’s framework shows how we can better understand people based on their relationships with others. Marston saw that you could categorize people based on how they were affected by their environment or how the environment affected them (he used the terms ‘Motor’ and ‘Stimuli,’ respectively).

In his book, Marston demonstrated how you could view people as being (or feeling) dominant over their surroundings or vice versa. He labeled these behaviors Dominance (d) or Submission (s).

Additionally, Marston understood that people acted a lot like nature around us. He saw that people sometimes behaved like a rushing river when it hit a wall; it moved with the wall rather than trying to move it out of its way. He labeled this behavior as Compliant ©.

On the other side of the spectrum, he saw that certain people were able to able to pull (his term is “gravitate”) others toward their ideas, goals, and perspectives like a planet holdings a moon in its orbit. He labeled this behavior as Inducement (I).

Marston recognized that we all used every behavior, but we had certain dominant or more often used behavior.

He imagined people as a color wheel. While everyone had a primary color, their wheel contained all of the other colors (behaviors) that they would use in certain situations.

What’s important to note is that Marston never created an instrument to measure his model.

For this reason, anyone can use Marston’s model to produce their DISC-model assessment.

Why are there so many versions of DISC?

William Moulton Marston developed DISC theory, but he never created an assessment.

Today, anyone can take Marston’s theory and create a DISC-based assessment. As you will see, many people have.

There are a few important names and organizations that have pushed the development and use of DISC:

Activity Vector Analysis (AVA); Walter Clarke & Associates

Walter Clarke was working for a major retailer in New York City when he recognized a correlation between people who enjoyed their job and their success. Clarke sought to understand if there were identifiable tendencies that you measure.

Following the “lexical approach,” Clarke identified a list of adjectives that were commonly used in describing others. He collected information on the adjectives using a checklist format, in which people were asked to check the specific words that describe them.

After collecting and analyzing the data on this instrument, he discovered that the four factors produced from the data (aggressive, sociable, stable, and avoidant) sounded a lot like DiSC.

Clarke was connected to Marston through Columbia University, and he concluded that Marston’s model of human behavior could best explain the data.

In 1948, Clarke developed the first assessment incorporating DISC theory, called the Activity Vector Analysis (AVA). However, Clarke also used several other theories, including Prescott Lecky’s model in the first version of the AVA.

Clarke’s assessment wasn’t called DISC, but it is the first assessment that uses Marston’s theory of identifying behavioral styles.

Self Discription; John Cleaver & Associates

In 1956, John Cleaver, an associate of Walter Clarke, created his assessment called Self Discription (misspelled intentionally to highlight the use of DISC). Cleaver’s assessment is still available today and is now called Cleaver DISC.

Cleaver was similar to Walter Clarke in that he was dismayed by how many unhappy people he encountered in their positions. Cleaver was motivated to develop a tool to improve employee productivity, negative attitudes, absenteeism, and workplace accidents.

Cleaver’s DISC Profile focuses on analyzing a person’s behavioral tendencies and how they relate to their work. The Self Discription (Cleaver DISC) was the first published assessment that used the term DISC in the instrument’s name.

The DiSC© Personal Profile System; Performax, Carlson Learning, Inscape, John Wiley & Sons, and John Geier

In the 1970s, another man named John Geier created his own version of the DiSC© Profile (with the small ‘i’). Geier was a faculty member at the University of Minnesota. Through his research, Geier discovered Marston and was determined to create an instrument that would use his DISC theory.

Geier would eventually leave his post at the university so he could start a business selling his DISC-based assessment. His company was called Performax. Geier’s company was purchased a sold a few times. Today his assessment tool is published by John Wiley & Sons (Wiley).

Geier’s assessment would become one of the most popular DISC Model assessments. Today, Wiley claims that their assessment is the “original DiSC assessment.” Geier likely believed this was true too.

On the 50th anniversary of Emotions of Normal People, Geier republished The Emotions of Normal People to celebrate Marston’s work. In it, he wrote an introduction stating (I use italics to emphasize my point):

“[Emotions of Normal People] did not achieve a wide audience, and the author is not mentioned in contemporary texts on psychology. However, I have frequently acknowledged Marston’s contributions to my work in applying behavioral science concepts to work and personal situations … I am most pleased to have been instrumental in bringing this author before a contemporary audience and in writing the introduction to this new edition.”

Geier thought he created the first DISC-based assessment. Unfortunately, that is just not true. Regardless, his work is very important in the development of the tool today.

Geier improved the reporting of the instrument by identifying the different classical styles based on a person’s line graph. Each learner would receive their primary DiSC style (D, i, S, or C), but they would also receive their Classical Pattern.

Geier’s instrument provided 15 Classical Profile Patterns, and these styles provided an in-depth description of a person’s behavior because they were based on the learner’s score on all four Dimensions of Behavior.

TTI Success Insights

Bill and Dave Bonnstetter started a consulting firm called Target Training International. They asked themselves a single question that would motivate their work:

“Could an agricultural salesperson sell more seed simply by looking at a farm?”

Bill Bonnstetter believed you could, and he partnered with John Geier to sell his paper instrument before creating his own.

Their company, TTI Success Insights, would grow exponentially, and they are now a global leader in the DISC world.

The DISC Landscape

When researching why there are so many DISC assessment versions, we must look at Geier. You can follow John Geier’s DiSC® tool and the other assessments that his affiliate partners produced:

  • 1970s: Geier leaves the University of Minnesota and creates the Personal Profile System.
  • 1980s:
  • Carlson Learning Systems buys Performax Systems International.
  • Bill Bonnstetter leaves to create and sell his version computerized version of DISC.
  • 1990s: Tony Alessandra leaves Carlson Learning’s partner network and starts his own assessment company, Assessments 24x7.
  • 2000s: Carlson Learning sells its assessment business (DiSC®) to an investment group which becomes Inscape Publishing
  • 2010 — Today:
  • Inscape Publishing is purchased by John Wiley & Sons
  • Take Flight with DISC is published by Assessments 24x7
  • Tony Robbins forms a partnership with Assessments 24x7.
  • DISC Basic is published by Assessments 24x7



Adam Stamm

Just your average irrational human trying to better understand the world.