Human beings have an obsessive relationship with categorizing themselves.
We categorize our music.
We categorize our coffee preferences.
We categorize our political beliefs, favorite streaming shows, and whether pineapple on pizza is a moral failing or a lifestyle choice.
So it was probably inevitable that eventually we’d start categorizing ourselves.
Not just casually either.
No, we’ve turned personality classification into an entire industry.
An empire of quizzes, charts, frameworks, acronyms, color wheels, animal metaphors, and corporate workshops where someone with a flip chart explains why you’re a “Blue Owl Strategist” while your coworker Kevin is apparently a “Red Fox Visionary.”
And yet despite all this psychological sorting, most of us still manage to behave unpredictably enough to make those personality models look like weather forecasts written by astrologers.
Which raises the obvious question:
When it comes to personality, how many ways are there to count it?
Psychologists have been trying to answer that question for over a century.
And like any good scientific effort involving human behavior, the result has been a mix of genuine insight, mild chaos, and an endless supply of personality quizzes that tell you you're a “thoughtful innovator with a passion for snacks.”
Let’s take a tour through humanity’s many attempts to count personality—and why we’re still arguing about it.
The Ancient Greeks: Four Personalities and Call It a Day
Let’s begin with the ancient Greeks.
Because when it comes to Western psychology, everything starts with philosophers wearing robes and making sweeping statements about human nature.
Around 2,400 years ago, the Greeks decided that personality could be explained through four bodily fluids.
Yes.
Fluids.
This theory was known as humorism, and it claimed that your personality was determined by the balance of four humors in your body:
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blood
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phlegm
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yellow bile
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black bile
If your humors were balanced, congratulations—you were emotionally stable.
If they weren’t, your personality took on one of four classic temperaments:
Sanguine – cheerful, social, optimistic
Choleric – ambitious, aggressive, intense
Melancholic – thoughtful, serious, prone to gloom
Phlegmatic – calm, relaxed, possibly napping
To modern ears, this sounds like medieval medical astrology.
But surprisingly, those four temperament categories stuck around for centuries.
Even today, modern personality models sometimes echo these ancient ideas.
Which is impressive when you consider they originated from people who believed emotional mood swings might literally be caused by too much bile.
Freud Enters the Chat
Fast forward to the early 20th century.
Enter Sigmund Freud, the man who looked at human personality and said:
“You know what this needs? More unconscious conflict.”
Freud’s view of personality involved three famous components:
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the id (your impulsive desires)
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the ego (your rational decision maker)
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the superego (your internal moral referee)
According to Freud, your personality was essentially the result of these three forces wrestling inside your mind like a psychological cage match.
The id wanted pleasure.
The superego demanded virtue.
And the ego stood in the middle desperately trying to prevent you from embarrassing yourself in public.
Freud also believed your childhood experiences played a massive role in shaping personality.
Which meant that if something seemed strange about your behavior as an adult, Freud would confidently point to something that happened when you were five and say:
“Ah yes, classic unresolved developmental tension.”
Freud’s ideas were controversial, speculative, and occasionally bizarre.
But they had one enormous influence:
They convinced the world that personality was something psychology could actually study.
The Trait Revolution
Eventually psychologists realized that analyzing dreams and childhood memories wasn’t the most reliable way to measure personality.
So researchers shifted toward something more scientific.
Traits.
A personality trait is basically a stable pattern in how someone behaves, thinks, or feels.
Instead of trying to interpret unconscious motives, psychologists began asking simpler questions:
How outgoing are you?
How organized are you?
How anxious do you tend to feel?
These questions led to decades of research trying to identify the fundamental building blocks of personality.
And after years of statistical analysis, researchers eventually landed on one of the most influential models ever created.
The Big Five Personality Traits
The Big Five model is the closest thing psychology has to a consensus personality framework.
Instead of dozens of complicated categories, it proposes five broad traits that capture most personality differences.
They are:
Openness
Creativity, curiosity, interest in new ideas.
High openness: loves art, novelty, weird documentaries about mushrooms.
Low openness: prefers routine and familiar experiences.
Conscientiousness
Organization, discipline, reliability.
High conscientiousness: the person who color-codes their calendar and arrives early.
Low conscientiousness: the person who forgot the meeting existed.
Extraversion
Social energy and engagement with others.
High extraversion: energized by social interaction.
Low extraversion: energized by canceling plans.
Agreeableness
Compassion, cooperation, kindness.
High agreeableness: empathetic and collaborative.
Low agreeableness: competitive and blunt.
Neuroticism
Emotional sensitivity and vulnerability to stress.
High neuroticism: easily anxious or reactive.
Low neuroticism: emotionally stable and calm.
Together these five dimensions capture an enormous amount of personality variation.
In fact, if you’ve ever taken a personality test that produced a spider-web chart with five lines, congratulations—you’ve encountered the Big Five.
It’s widely respected because it’s based on extensive data rather than mystical symbolism or corporate branding.
Which is why researchers tend to trust it more than personality systems that assign you a spirit animal.
The Myers-Briggs Industrial Complex
Now we arrive at the personality test that refuses to die.
The Myers-Briggs Type Indicator, or MBTI.
If you’ve ever worked in an office, there is a very good chance you’ve taken this test.
Usually during a workshop that promises to “unlock the secrets of teamwork.”
The MBTI divides people into 16 personality types, based on four binary categories:
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Introvert vs Extravert
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Sensing vs Intuition
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Thinking vs Feeling
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Judging vs Perceiving
Combine those letters and you get types like:
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INTJ
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ENFP
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ISTP
Suddenly people start introducing themselves like personality Pokémon.
“Hi, I’m an INFJ.”
“Oh wow, I’m an ESTP.”
“Great, I’m a coffee.”
The problem with Myers-Briggs is that psychologists have criticized it for years.
The categories are rigid.
The results often change when people retake the test.
And the system assumes personality fits neatly into boxes rather than continuous traits.
Yet despite these criticisms, MBTI remains wildly popular.
Why?
Because people love personality labels.
They provide a sense of identity.
They create community.
And they give us a convenient explanation for why we behave the way we do.
Even if the science behind them is… let's say “enthusiastically debated.”
Personality Tests on the Internet
If the Big Five represents academic psychology and Myers-Briggs represents corporate workshops, then the internet represents the third major personality testing frontier.
The quiz economy.
You know the ones.
“Which medieval weapon matches your personality?”
“What type of houseplant are you?”
“Which pasta shape represents your emotional life?”
And before you laugh, remember that millions of people take these quizzes.
Because personality classification taps into something deeply human.
We want to understand ourselves.
And we want language to describe our differences.
Even if that language occasionally involves discovering you’re “emotionally equivalent to a ravioli.”
Why Personality Is Hard to Count
The real reason psychologists struggle to count personality traits is simple:
Humans are complicated.
We’re not static machines with predictable settings.
Personality shifts depending on:
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environment
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mood
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context
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life stage
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stress levels
Someone might appear introverted at a party but extremely talkative with close friends.
Another person might seem calm most of the time but become intensely anxious under pressure.
Personality traits capture tendencies, not fixed destinies.
Which makes measuring them a lot like measuring ocean waves.
You can observe patterns.
But the surface never stops moving.
Culture Complicates Everything
Another challenge is culture.
Personality traits don’t always mean the same thing in different societies.
For example:
In some cultures, assertiveness is admired.
In others, humility is valued more highly.
A personality test created in North America might interpret certain behaviors very differently in Japan, Brazil, or Nigeria.
So psychologists must constantly ask:
Are we measuring universal personality traits?
Or are we measuring culturally specific behavior patterns?
The answer is probably some combination of both.
The Neuroscience Angle
Modern research has also begun exploring how personality relates to brain function.
For example:
Extraversion is linked to reward sensitivity in the brain’s dopamine system.
Neuroticism correlates with activity in regions involved in threat detection.
Conscientiousness may involve networks responsible for impulse control and planning.
This doesn’t mean personality is purely biological.
But it does suggest that some traits have neurological foundations.
Which is fascinating when you realize personality isn’t just psychological—it’s also physiological.
Your brain literally participates in shaping who you are.
The Dark Side of Personality
Of course, not all personality traits are sunshine and social harmony.
Psychologists also study darker traits known as the Dark Triad:
These traits involve tendencies toward manipulation, self-centeredness, and emotional detachment.
And while they sound alarming, research shows they exist on a spectrum.
Not everyone with a hint of narcissism is a villain.
But understanding these traits helps psychologists study power dynamics, leadership styles, and workplace behavior.
Which explains why certain executives sometimes score surprisingly high on them.
The Illusion of Perfect Labels
Despite centuries of research, one uncomfortable truth remains:
No personality model perfectly captures human complexity.
Every framework simplifies reality.
The Big Five simplifies personality into five dimensions.
Myers-Briggs simplifies it into sixteen types.
Ancient Greeks simplified it into four humors.
Each system highlights certain patterns while ignoring others.
And yet we keep inventing new personality frameworks anyway.
Because humans have a deep desire to make sense of themselves.
We want maps for navigating our own minds.
Even if the maps are imperfect.
Why Personality Still Matters
Despite all the debates, personality research has produced valuable insights.
It helps explain patterns in:
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career choices
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relationship compatibility
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stress responses
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leadership styles
Personality traits can predict behaviors like:
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job performance
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risk tolerance
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political attitudes
And understanding personality differences can improve communication between people who think very differently.
Which is extremely useful in workplaces, friendships, and families.
Because half of human conflict comes from misunderstanding how others think.
The Real Number of Personality Types
So after thousands of years of philosophy, psychology, and statistical analysis…
How many personalities are there?
The unsatisfying but honest answer is:
As many as there are people.
Personality models help us understand patterns.
But every individual is a unique combination of traits, experiences, values, and circumstances.
No single framework can capture that fully.
Which is both frustrating for scientists and reassuring for the rest of us.
Because it means you’re not just a personality code.
You’re a constantly evolving combination of tendencies and choices.
Counting the Ways
In the end, the question “How can we count personality?” might be slightly misguided.
Personality isn’t a fixed inventory of traits.
It’s a dynamic system.
A mixture of biology, psychology, culture, and life experience.
And while psychologists will continue refining their models and developing new ways to measure personality, one thing will remain true:
Humans will always be more complicated than the systems we invent to explain them.
Which is probably a good thing.
Because if personality were simple enough to count precisely, the world would be far less interesting.
And far more predictable.
And frankly, who wants to live in a universe where your entire identity can be reduced to a four-letter code and a pie chart?
Certainly not the person who just took a quiz and discovered they’re apparently an emotionally complex lasagna.