# DISC assessment

DISC assessments are behavioral self-assessment tools based on psychologist William Moulton Marston's DISC emotional and behavioral theory, first published in 1928. These assessments aim to improve job performance by categorizing individuals into four personality traits: dominance, inducement, submission, and compliance.
However, the scientific validity of DISC has been a subject of debate, with some considering it to be a pseudoscience. Critics question its reliability and accuracy in predicting job performance. The theory proposes four central traits to describe personality, but its scientific basis remains contested.

## History

The DISC personality theory was first outlined in the book "Emotions of Normal People", published in 1928, and written by William Moulton Marston, with likely contributions by Olive Byrne and Elizabeth Holloway Marston.

## Types

The first self-assessment based on Marston's DISC theory was created in 1956 by Walter Clarke, an industrial psychologist. In 1956, Clarke created the Activity Vector Analysis, a checklist of adjectives on which he asked people to indicate descriptions that were accurate about themselves. This self-assessment was intended to aid businesses in choosing qualified employees. John Geier then developed DiSC (lower case 'i' intentional).
Clarke and Peter Merenda published their findings on the new instrument in the January 1965 issue of the Journal of Clinical Psychology. However, instead of using a checklist, the "Self Description" test asks respondents to make a choice between two or more terms. "Self Description" was used by John Geier to create the Personal Profile System in the 1970s.

## Uses

The self-assessment tools are designed for use in personnel management in businesses. A DISC assessment helps to identify workstyle preferences, determines how someone would interact with others, and provides insight on work habits.
Organizations often use the DISC assessment for various applications, including team building, leadership development, communication training, and conflict resolution. While it can provide valuable insights into individual and team dynamics, it is essential to interpret the results with caution and avoid oversimplifying complex human behavior.
DISC has been used to help determine a course of action when dealing with problems as a leadership team by taking the various aspects of each DISC type into account when solving problems or assigning jobs.

### Psychometric properties

The DISC assessments have demonstrated no ability to predict job performance as their validity is low. The assessment has high reliability, meaning that an individual will consistently get the same result over time.

#### Reliability

A Russian pilot study found a coefficient of .89 for retesting after one week.
A research paper in the Scandinavian Journal of Psychology found acceptable levels of internal consistency in a normative DISC assessment, but also indications that the DISCUS-dimensions were not psychometrically independent, and that the DISC data structure could better be explained as combinations of the Big-Five personality traits than as independent traits.

#### Validity

Psychologist Wendell Williams has criticized the use of DISC in the employee recruitment process. In his criticism, Williams argues that a good job performance test should be well constructed, have test-retest reliability, have Criterion Validity for criteria of job performance, and incorporate the theory of job performance in the test's design.
A 2013 German study studied the validity and reliability of a DISC assessment, Persolog, to see if it was up to standards for the TBS-DTk the test assessment system of the Diagnostics and Test Board of the Federation of German Psychological Associations. The study found that it "largely" met the requirements in terms of reliability but not at all in terms of validity.

## Theory

The DISC theory describes personality through four central traits:
* Dominance: active use of force to overcome resistance in the environment
* Inducement: use of charm in order to deal with obstacles
* Submission: warm and voluntary acceptance of the need to fulfill a request
* Compliance: fearful adjustment to a superior force.
Marston described the DISC characteristics in his 1928 book Emotions of Normal People, which he generated from emotions and behavior of people in the general population. According to Marston, people illustrate their emotions using four behavior types: Dominance, inducement, submission, and compliance.
He argued that these behavioral types came from people's sense of self and their interaction with the environment. He based the four types on two underlying dimensions that influenced people's emotional behavior. The first dimension is whether a person views their environment as favorable or unfavorable. The second dimension is whether a person perceives themselves as having control or lack of control over their environment.