History of Human Behaviour Study

Carl Jung's theory of psychological types is a cornerstone of his analytical psychology. He proposed that differences in behaviour result from individuals' inherent preferences in how they perceive the world and make decisions. Jung identified two primary dichotomies of cognitive functions:

Additionally, Jung introduced the concepts of Extraversion and Introversion as attitudes that influence the direction of these cognitive functions.

Extraverts are oriented outward, towards the external world, and gain energy from interaction and action. Introverts are oriented inward, towards the internal world, and gain energy from reflection and solitude.

These cognitive functions and attitudes combine to form different personality types.

For example, an individual might be an extraverted thinker, an introverted feeler, etc. Jung's psychological types provided a framework for understanding the diverse ways in which people perceive the world and make decisions.

Galen, an influential Greek physician and philosopher, expanded Hippocrates' theory of the four humours, linking them more explicitly to personality types. Galen's theory suggested that the balance or imbalance of these humours in the body influenced not only physical health but also psychological traits and temperaments.

In Galen's theory of the four humours, each humour corresponds to a distinct personality type:

Sanguine individuals, influenced by blood, are typically optimistic, sociable, and enthusiastic, although they can be impulsive.

Choleric personalities, associated with yellow bile, are passionate, ambitious, and assertive leaders, but often quick-tempered.

Those with a melancholic temperament, influenced by black bile, are introspective and analytical but may tend towards anxiety and sadness.

Lastly, phlegmatic individuals, governed by phlegm, are calm, reliable, and rational, known for their peacekeeping abilities, though sometimes seen as unambitious and resistant to change.

Galen's interpretation of the humours had a significant and lasting impact on medieval and Renaissance medicine and psychology. His work influenced the understanding of personality well into the 18th century. He linked physical health with psychological well-being and personality traits.

Hippocrates, often called the "Father of Medicine", is known for his influential theories about bodily humours, which he extended to explain personality traits.

Hippocrates' theory of personality, rooted in the concept of four bodily humours, linked individual temperaments to the balance of these fluids.

The sanguine temperament, associated with blood, described individuals as sociable, optimistic, and active, reflecting a carefree and impulsive nature, similar to the element of air.

In contrast, the choleric temperament, linked to yellow bile, characterised people as fiery, passionate, and ambitious, often assertive and dominant, akin to the element of fire.

On the other hand, black bile was associated with the melancholic temperament, representing introspective, reflective individuals prone to gloom, often analytical and detail-oriented, reflecting the element of earth.

Finally, the phlegmatic temperament, connected to phlegm, described people as calm, reliable, and relaxed, typically passive and consistent, similar to the element of water. The belief that these humours influenced physical health and people's emotional state formed the basis of Hippocrates' understanding of personality.

Empedocles, a pre-Socratic Greek philosopher, proposed a theory of four classical elements that he believed constituted the physical universe: earth, air, fire, and water. Although Empedocles did not directly apply these elements to personality theories as we understand them today, his ideas laid the groundwork for later conceptions of personality in ancient medicine and philosophy.