For over 2,500 years, thinkers and researchers have sought to understand the diversity of human temperament and behavior. The concept of four distinct personality types has evolved from early philosophical explorations to modern psychological frameworks. Along the way, each contribution added depth and nuance, culminating in a practical, accessible system of understanding personality that continues to resonate today.
Empedocles, a Greek philosopher from the 5th century BC, proposed the idea of the four classical elements—earth, air, fire, and water—as the foundational components of the universe.
Illustration of Empedocles
(494 - 443 BC)
While his work primarily focused on explaining the natural world, he associated these elements with distinct qualities or character traits. Earth symbolized stability and reliability, air represented liveliness and change, fire embodied passion and intensity, and water suggested adaptability and calm.
Four Elements Model
15th Century Illustration
Though not specifically tied to personality, these characterizations hinted at the early recognition of distinct temperamental patterns in human nature. His work laid the philosophical groundwork for later thinkers who began to relate these elements to the human psyche.
Building on Empedocles’ elements, Hippocrates, the father of medicine, introduced the theory of the four humors around the 4th century BC. He believed that human health and temperament were influenced by the balance of bodily fluids: blood, yellow bile, black bile, and phlegm.
Illustration of Hippocrates of Kos
(460 - 370 BC)
Hippocrates observed that different people displayed distinct temperaments and linked these to the humors—sanguine (optimistic and lively), choleric (ambitious and fiery), melancholic (thoughtful and reserved), and phlegmatic (calm and consistent).
The Four Humors
16th Century Illustration
While Hippocrates’ focus was on physical health rather than personality, his recognition of four distinct temperamental types set a precedent for future explorations of personality systems.
The Roman physician Galen expanded on Hippocrates’ work in the 2nd century AD, systematically linking the four humors to specific personality traits. Galen’s framework formalized the idea of four temperaments, directly associating them with behavioral patterns.
Illustration of Claudius Galenus
(129 - 216 AD)
He described sanguine individuals as sociable and energetic, choleric as goal-oriented and assertive, melancholic as introspective and perfectionistic, and phlegmatic as relaxed and cooperative.
The Four Temperaments
18th Century Illustration
Galen’s work made the connection between physical and psychological traits explicit, influencing centuries of thought on personality and temperaments.
In the 20th century, William Moulton Marston developed the DISC model of personality, building on earlier concepts of four types while shifting the focus to observable behavior and emotional responses.
Illustration of William Marston
(1893 - 1947 AD)
Unlike Hippocrates and Galen, Marston did not tie his model to biological or medical theories but rather to how people interact with their environments.
Original DISC Emotion & Color Model
DISC identifies four core types—Dominance, Influence, Steadiness, and Conscientiousness —each reflecting a unique approach to problem-solving, communication, and decision-making. Marston’s DISC model became widely adopted in organizational and personal development contexts due to its simplicity and practicality.
Today's circular color spectrum provides a clear and intuitive way to represent the four core personality types. Red conveys bold, action-driven traits; yellow symbolizes energetic and socially engaging characteristics; green reflects calm, supportive qualities; and blue represents precision and analytical thinking.
The circular layout emphasizes how personality types flow into one another, blending at the edges to create unique combinations of traits. For example, a person who is predominantly red may also exhibit elements of yellow or blue, just as the colors themselves blend to form shades. This approach visually captures the dynamic nature of personality, illustrating how traits interconnect and adapt within the broader spectrum of human behavior.