Hippocrates' Four Humours: From Ancient Temperaments to Modern Personality Psychology

Choleric, sanguine, phlegmatic and melancholic. The four temperaments have influenced ideas about personality for centuries. But how did an ancient Greek medical theory eventually connect with Jungian psychology and modern tools like Insights Discovery?

Long before personality profiles, psychometric questionnaires or workplace colour models, people were trying to answer a remarkably familiar question:

Why do different people behave so differently?

Why are some people naturally energetic and sociable?

Why are others more reflective?

Why do some appear calm under pressure while others react quickly and forcefully?

More than two thousand years ago, Greek physicians attempted to explain those differences through a theory that became known as the four humours.

Yellow bile.

Blood.

Phlegm.

Black bile.

It sounds a long way from modern psychology.

And medically, it absolutely is.

But the ideas that subsequently developed around those four humours created one of the earliest enduring attempts to describe different human temperaments.

Those ideas survived for centuries and were repeatedly reinterpreted by physicians, philosophers and eventually psychologists.

Follow that history far enough and you arrive at people such as Wilhelm Wundt and Carl Jung.

And that is where the story becomes particularly interesting for anyone familiar with Insights Discovery.

What Were Hippocrates’ Four Humours?

Hippocrates was a Greek physician who lived around the fifth and fourth centuries BC and is often described as one of the most influential figures in the history of Western medicine.

You may have heard of the Hippocratic Oath, the code of medical ethics attributed to the ancient Greek physician, requiring new doctors to swear to uphold specific professional and moral standards.

The medical tradition associated with Hippocrates attempted to understand illness through natural rather than purely supernatural causes, evil spirits or the will of the Gods.

One important idea within this tradition was that health depended upon balance within the body.

The body was believed to contain four principal fluids, or humours:

Yellow bile
Blood
Phlegm
Black bile

Good health was associated with these being appropriately balanced.

Illness could occur when one became excessive or deficient.

Today, of course, medicine has moved far beyond humoral theory.

But the influence of the idea lasted for well over a thousand years.

More interesting from a personality perspective is what happened next.

From Four Humours to Four Temperaments

The link between bodily humours and personality became particularly associated with the Greek physician Galen, who lived several centuries after Hippocrates.

The four humours gradually became associated with four characteristic temperaments:

Choleric
Sanguine
Phlegmatic
Melancholic

These weren’t simply descriptions of health.

They became ways of thinking about how people characteristically behaved.

And suddenly we have something that begins to sound much more familiar.

The Choleric Temperament

The choleric temperament was associated with yellow bile.

Traditional descriptions emphasised qualities such as:

Drive
Ambition
Decisiveness
Assertiveness
Action

A choleric person might be described as someone inclined to take charge or move quickly towards an objective.

The potential downside was that this energy could become impatience, dominance or anger.

The Sanguine Temperament

The sanguine temperament was associated with blood.

People described as sanguine were traditionally characterised as:

Sociable
Optimistic
Enthusiastic
Expressive
Energetic

They might enjoy interaction, variety and stimulation.

At the same time, traditional descriptions sometimes portrayed them as impulsive, easily distracted or quick to lose interest.

The Phlegmatic Temperament

The phlegmatic temperament was associated with phlegm.

It was traditionally connected with qualities such as:

Calmness
Patience
Reliability
Consistency
Consideration

Phlegmatic individuals were often portrayed as steady and dependable.

At the same time, that steadiness could be interpreted as reluctance to change or a lack of urgency.

The Melancholic Temperament

The melancholic temperament was associated with black bile.

It became connected with characteristics such as:

Thoughtfulness
Reflection
Sensitivity
Precision
Perfectionism

Traditional descriptions often presented melancholic people as deep thinkers who paid significant attention to quality and detail.

That depth could also become excessive concern, pessimism or rumination.

Why Did the Four Temperaments Survive?

By the eighteenth and nineteenth centuries, medicine had developed enormously.

Blood circulation, anatomy, physiology and eventually microbiology provided much better explanations for how the human body actually worked.

Humoral medicine gradually disappeared.

Yet the four temperaments didn’t disappear with it.

Instead, philosophers and early psychologists continued exploring them as descriptions of personality.

One particularly important development came from Immanuel Kant, who organised temperament around broader dimensions relating to feelings and activity.

Then came Wilhelm Wundt.

And this is where the journey towards modern personality psychology becomes particularly interesting.

Wilhelm Wundt: Moving From Types to Dimensions

Wilhelm Wundt is often associated with the emergence of psychology as an experimental discipline.

When considering temperament, he moved away from the idea that everyone must belong neatly within one of four boxes.

Instead, he explored temperament using dimensions.

Two of the dimensions associated with Wundt’s interpretation concerned:

Emotional strength
Speed or changeability

That might sound like a relatively small change.

It wasn’t.

Because there is an enormous difference between saying:

You are one personality type.

and saying:

Your personality reflects different positions across several dimensions.

That shift towards preference, proportion and combination feels much closer to how many modern approaches understand personality.

Wundt moved from four independent temperament categories towards a two-dimensional system incorporating all four.

And eventually another hugely influential thinker would take the exploration of psychological differences much further.

Enter Carl Jung

In the early twentieth century, Swiss psychiatrist Carl Gustav Jung developed his theory of psychological types.

Rather than explaining personality through bodily fluids, Jung explored patterns in how people direct their energy and engage with the world.

His theory included two attitudes:

Extraversion
Introversion

And four psychological functions:

Thinking
Feeling
Sensation
Intuition

Jung wasn’t simply recreating the four temperaments.

His theory was significantly more developed and psychologically focused.

But you can see an interesting thread running through the history.

For centuries, thinkers had been trying to describe recurring differences between people.

Jung provided a new psychological framework for exploring those differences.

And his work subsequently influenced several personality models that remain widely used today.

So How Does This Connect to Insights Discovery?

This is where we need to be careful.

You may see diagrams online that place:

Choleric alongside red
Sanguine alongside yellow
Phlegmatic alongside green
Melancholic alongside blue

It’s a tempting comparison.

But I wouldn’t describe those as direct equivalents.

Insights Discovery is not based on Hippocrates’ four humours.

Insights Discovery is a psychometric model based on the psychological type theory of Carl Jung. Insights describes the model as using a unique combination of four colour energies to help people understand behavioural preferences.

Those four colour energies are:

Fiery Red
Sunshine Yellow
Earth Green
Cool Blue

And crucially:

everyone has access to all four.

Insights isn’t about deciding whether you’re “a Red”, “a Yellow”, “a Green” or “a Blue”.

It explores the unique combination and preference for those energies within an individual. Insights itself explicitly describes people as having every colour energy, while typically feeling more comfortable with some than others.

That’s a significant distinction.

Ancient Types vs Modern Preferences

This may be the most interesting part of the entire journey.

Early temperament theories tended towards categories.

You were sanguine.

Or choleric.

Or melancholic.

Or phlegmatic.

Modern personality approaches increasingly recognise something much more complex.

People don’t fit neatly into four boxes.

Within Insights Discovery, for example, two people could both demonstrate significant Fiery Red energy while being very different people.

One may also bring significant Cool Blue energy.

Another may combine that Fiery Red with substantial Sunshine Yellow and Earth Green.

The interaction between preferences matters.

Context matters.

Adaptation matters.

That’s why reducing somebody to their “top colour” misses so much of the value of a proper Insights Discovery profile.

Why Four-Part Personality Models Keep Appearing

There is something fascinating about the persistence of four-part frameworks.

Across history, people have repeatedly created ways of simplifying human differences into memorable patterns.

The four humours are one example.

Later temperament models are another.

Jung explored psychological functions and attitudes.

Modern workplace frameworks often use quadrants, colours, letters or dimensions to make complex psychological ideas easier to discuss.

The important question isn’t whether four is somehow a magical number.

It’s whether the framework helps us have a better conversation.

A useful personality framework should create curiosity rather than labels.

It should help us ask:

Why might somebody see this differently from me?
How might my communication style affect them?
What am I naturally comfortable doing?
Where might I need to adapt?
What strengths could somebody with very different preferences bring?

That’s when personality psychology becomes practically useful.

From Understanding Personality to Understanding Yourself

For me, this is where the history becomes more than an interesting psychology lesson.

The question humanity has been asking for thousands of years is still incredibly relevant.

Why do I behave the way I do, and why do other people behave differently?

We now have substantially better tools for exploring that question than Hippocrates or Galen ever had.

But the curiosity behind it hasn’t changed.

Understanding behavioural preferences can help us become more aware of:

How we communicate
How we make decisions
How others experience us
What gives us energy
What frustrates us
What happens to our behaviour under pressure
Where we may need to adapt

And unlike an online personality quiz that gives you a label and sends you on your way, a detailed Insights Discovery profile debrief gives you something to explore.

Not:

Which type am I?

But:

What does my unique combination of preferences mean for how I work with other people?

I think that’s a much more useful question.

Final Thought

More than two thousand years separate Hippocrates from the personality tools we use today.

The science has changed beyond recognition.

But the question hasn’t.

Why are we different?

The four humours were an early attempt to make sense of those differences.

The four temperaments carried that thinking into discussions about personality.

Wundt began moving from categories towards dimensions.

Jung gave us a sophisticated psychological theory of preferences.

And today, tools such as Insights Discovery allow us to turn those ideas into practical conversations about self-awareness, communication and relationships.

So perhaps the most interesting thing about the four humours isn’t whether somebody is sanguine or choleric.

It’s that more than two millennia later, we’re still fascinated by exactly the same challenge:

understanding ourselves, so we can understand each other better.

If you’re curious about what modern Jungian psychology can reveal about your own behavioural preferences, explore what an Insights Discovery profile can tell you.