DISC Assessment, History & Theory | Thomas International DISC Assessment Theory

DISC Assessment Theory

Dr. Marston's Theory of Human Behavior - DISC

The Thomas Personal Profile Analysis (PPA) has its original impetus from the writings of Marston (1928, 1931) who postulated a theory of human behavior as a function of two bipolar dimensions, one external and the other internal.

These two dimensions provided a matrix from which the individual’s typical pattern of interaction could be described through four characteristics: Dominance, Inducement, Submission, Compliance (DISC).

Martson’s theory assumed that most people are capable of showing all four of these patterns at different times. However it is also assumed that an individual develops, through learning and reinforcement, a style of life which places particular emphasis on certain aspects of behavior and less on others. Further research by others in the 1950s confirmed this proposal that behavior can be measured along the two axis/four dimensions as suggested by Marston. These include Gordon (1953), Denton (1954), LaForge (1955), Suczek (1955) and Clarke (1956).

Dr. Hendrickson - Applying DISC in the Work Place

In the late 1950s and early 1960s, Dr. Thomas Hendrickson of TM Hendrickson and Associates, developed Marston’s insights further to produce the Thomas Personal Profile Analysis for the work place. The Thomas PPA has since gone through rigorous tests to determine its consistency and validity. Studies done in the UK have compared PPA with 16PF and OPQ assessments and found the Thomas PPA to be consistent in identifying similar traits in the same candidates tested repeatedly.

The Thomas PPA is a forced choice IPSATIVE instrument. This means it describes the individual in a self referential way and is regarded as providing information of importance and value to employers making personnel decisions. The Thomas PPA attempts to determine whether individuals see themselves as characteristically seeking out and/or reacting to work place situations that they perceive as friendly or challenging and to reveal if the response pattern is one of activity or passivity.

The Thomas PPA is a self administered forced choice adjective checklist consisting of 24 tetrads of descriptive words from each of which applicants are asked to select which they believe describes them most and which least. The words chosen in Hendrickson’s first experiments were based on Marston’s definitive work. As far as possible the words selected had “face validity” with Marston’s model and each tetrad related to one of his original four DISC dimensions.

Dr. Carl Jung - Influence on the Thomas PPA

The Thomas PPA, while based primarily on Marston's theories, also draws on the contribution of Dr. Carl Gustav Jung. Jung's work starts from the assumption that there are three pairs of functions that are expressed differently in each person: extroversion-introversion; perception-intuition; thinking-feeling. In each case, a person shows a preference of one of the two possibilities; this results in eight possible combinations or types. Dr. Marston's system is in complete mathematical harmony with the works of Jung.