From Blood Types to Algorithms: A Brief History of Categorizing Ourselves
From ancient bodily fluids to modern data surveillance—why are we so obsessed with labeling our personalities?
Humans have a strange obsession: we love putting ourselves in boxes.
Whether it’s checking our horoscopes, sorting ourselves into Hogwarts Houses, or wearing our MBTI type like a badge of honor, we are constantly searching for a label that says: This is who you are. You make sense.
But how did we get here? How did we go from believing our personality was made of "bodily fluids" to letting algorithms predict our behavior better than our algorithms can?
The Era of Fluids (400 BC)
"You're just acting this way because of your bile."
It started in Ancient Greece. Hippocrates and later Galen didn't have psychology; they had biology. They believed your temperament was controlled by the balance of four fluids (Humors) in your body.
- Sanguine (Blood): Social, optimistic, and energetic.
- Melancholic (Black Bile): Deep, poetic, and sad.
- Choleric (Yellow Bile): Ambitious, angry, and leader-like.
- Phlegmatic (Phlegm): Calm, slow, and consistent.
It sounds ridiculous now, but it was a massive leap forward. It was the first time humanity said, "Hey, maybe people react differently because they are built differently."
The Era of The Grid (1940s)
"Put yourself in the box."
Fast forward to World War II. Two women, Katharine Cook Briggs and her daughter Isabel Briggs Myers, were watching the world change. Women were entering the industrial workforce in droves, and they needed a way to sort people into the right jobs efficiently.
They were deeply inspired by Carl Jung—the Swiss psychologist who coined "Introvert" and "Extrovert"—but Jung's work was dense, mystical, and fluid. Jung famously hated rigid labels, saying, "Every individual is an exception to the rule."
Katharine and Isabel took Jung's fluid concepts and hardened them into a Grid. They created the four dichotomies (E/I, S/N, T/F, J/P) that gave birth to the 16 types.
The Myers-Briggs Type Indicator (MBTI) was born. It wasn't just a test; it was a product. It told you that you weren't "weird" or "disordered"—you were just an INFP. It was validating, positive, and commercially unstoppable.
The Era of Data (1980s)
"The Truth is Boring."
While the public loved MBTI, academic psychologists hated it. It wasn't reliable—people often got different results when re-taking it.
So, scientists went to the dictionary. They used computers to analyze thousands of words used to describe personality and found they all clustered into five statistical buckets. This became The Big Five (OCEAN):
- Openness
- Conscientiousness
- Extraversion
- Agreeableness
- Neuroticism
The Big Five is scientifically robust. It predicts your career success and health outcomes. But it has a marketing problem: it doesn't give you a cool tribe to belong to. Being "Moderately Conscientious with High Neuroticism" doesn't look great in an Instagram bio.
The Era of Virality and Surveillance (2010s - Present)
"The Algorithm Knows You Best."
The Internet changed everything. First, it was BuzzFeed. We treated personality tests as social currency. We took "Which Pizza Topping Are You?" quizzes not to learn about ourselves, but to perform an identity for our friends.
Then, things got dark.
In 2014, researchers like Michal Kosinski showed that a computer model could assess your personality better than your work colleagues by analyzing just 10 of your Facebook Likes. With 300 Likes, it could know you better than your spouse.
This led to the Cambridge Analytica scandal. We realized that while we were busy answering quizzes, the platforms were quietly "typing" us based on our behavior. We moved from taking tests to being the test.
Conclusion
We started with blood, moved to checklists, and ended up as data points.
But despite the technology, the drive remains the same. We crave the mirror. We want to be seen. Whether you trust the stars, the four letters, or the algorithm, remember: The map is not the territory.
You are always more than the label.