The Myers-Briggs test began as a mother’s attempt to analyze her daughter’s boyfriend. Katharine Briggs, inspired by Carl Jung’s work, created a personality-typing system that her daughter Isabel later turned into the MBTI. Today, it’s used in workplaces, schools, and online quizzes around the world.

But there's a catch: psychologists say it doesn’t hold up. The MBTI forces people into binary types (introvert or extrovert, thinker or feeler), but most traits exist on a spectrum. Worse, many test-takers get a different result the second time around.

That’s why researchers favor the Big Five model, which rates people across five scientifically validated traits and has much stronger predictive power. MBTI may be fun, but when it comes to accuracy, science swipes left.