It all started …

In 1928, he published the book "Emotions of Normal People," developing what we know and use today as the DISC Personality System, which was validated during his studies at Harvard University. He saw our DISC personality styles as being both internal and innate but impacted largely by our external environment. William Moulton Marston defined the four quadrants of personality as Dominance, Influence, Steadiness, and Compliance, which we still use in DISC Personality Tests today. However, the history of DISC doesn't come to its present state until 1940. In 1940, Walter Clark took the theory of William Moulton Marston and developed the first DISC personality profile. The same DISC personality profile that is still in use today!