“I’m an INTJ, so I prefer working alone. That’s just how my brain is wired.”

I’ve heard variations of this hundreds of times. In job interviews. In team retrospectives. In dating profiles. In therapy sessions.

Myers-Briggs (MBTI), Enneagram, DiSC, StrengthsFinder—personality tests are everywhere. Companies use them for hiring. Therapists use them for counseling. People use them to explain their behavior, predict compatibility, and justify their preferences.

But here’s the uncomfortable truth I’ve discovered after diving deep into the research:

Most popular personality tests have about as much scientific validity as your horoscope.

And I say this as someone who spent years believing I was an INFP, then an INTJ, then questioned the whole system when I kept getting different results.

In this post, I’m going to examine the science (or lack thereof) behind personality tests, explain why they’re so seductive despite being flawed, and share what actually works if you want to understand yourself better.

The Seductive Appeal of Personality Tests

Before we tear them apart, let’s acknowledge why personality tests are so compelling.

When I first took the Myers-Briggs test at age 22, reading my INFP profile felt like someone had written my biography. It described my:

  • Preference for deep conversations over small talk
  • Tendency to overthink decisions
  • Idealism and value-driven approach to life
  • Discomfort with conflict

It felt deeply true.

This is the power of personality tests—they provide:

1. A Framework for Understanding Yourself

  • Labels and categories for nebulous feelings
  • Explanations for behaviors you couldn’t articulate
  • A sense of self-knowledge

2. Validation

  • “I’m not weird, I’m just an INFP!”
  • Permission to be who you are
  • Explanation for struggles (“INFPs find deadlines stressful”)

3. Connection

  • Shared language with others
  • Community (“fellow INFJs understand me”)
  • Instant rapport (“Oh, you’re an ENFP? That explains everything!”)

4. Prediction and Control

  • “I’ll pair well with an ENFJ”
  • “I shouldn’t take jobs that require X”
  • Sense of understanding your future

5. Identity

  • Quick self-descriptor
  • Badge (“INTJ - The Architect”)
  • Shorthand for personality

These are powerful psychological needs. Personality tests promise to meet them.

But do they actually deliver? And at what cost?

The Myers-Briggs Type Indicator (MBTI): A Case Study in Pseudoscience

Let’s start with the most popular personality test in the world.

The Origins: Not Exactly Scientific

Myers-Briggs was created by Katharine Cook Briggs and her daughter Isabel Briggs Myers in the 1940s.

Their qualifications?

  • Zero formal training in psychology
  • Zero formal training in psychometrics
  • Zero formal training in statistics

Katharine was a homemaker interested in Carl Jung’s theories. Isabel was a mystery novelist.

They created the MBTI based on their interpretation of Jung’s work. Jung himself never intended his ideas to be used this way and warned against putting people into rigid categories.

The test was popularized not through academic validation, but through corporate training programs. It’s now a $20 million annual industry.

The Four Dichotomies

MBTI sorts you into 16 types based on four binary dimensions:

E vs. I (Extraversion vs. Introversion)

  • Where you get energy: from people or from alone time

S vs. N (Sensing vs. Intuition)

  • How you take in information: concrete facts or abstract patterns

T vs. F (Thinking vs. Feeling)

  • How you make decisions: logic or values

J vs. P (Judging vs. Perceiving)

  • How you approach life: structured or flexible

You get labeled with four letters: INTJ, ENFP, ISTP, etc.

Sounds reasonable, right?

Here’s the problem: almost none of this holds up to scientific scrutiny.

Scientific Problem #1: Poor Test-Retest Reliability

If a personality test measures stable traits, you should get the same result when you take it multiple times.

MBTI fails this spectacularly.

Research shows that 50% of people get a different type when retaking the test just 5 weeks later.

Think about that. Flip a coin, and there’s a 50% chance your “personality type” changes in a month.

My personal experience:

  • Age 22: INFP
  • Age 25: INTJ
  • Age 28: INTP
  • Age 30: INFJ

Did my personality fundamentally change four times? Or is the test measuring something unstable and context-dependent?

The problem is that many questions put you near the middle of dimensions. If you’re 51% Thinking and 49% Feeling, you get labeled “T”. But tomorrow, when you’re in a different mood, you might score 49% Thinking and 51% Feeling—now you’re “F”.

Your label changes even though you barely changed at all.

This is called the “dichotomy problem.” MBTI treats continuous traits as binary categories, which doesn’t reflect psychological reality.

Scientific Problem #2: Lack of Predictive Validity

A good personality test should predict behaviors, outcomes, and life satisfaction.

MBTI doesn’t.

Studies have found:

  • No correlation with job performance (despite being used in hiring)
  • No correlation with career satisfaction
  • No correlation with relationship compatibility
  • Weak correlation with actual behavior

The test tells you almost nothing useful about how you’ll perform at work, whether you’ll be satisfied in a career, or whether you’ll be compatible with a romantic partner.

Compare this to the Big Five (which we’ll discuss later), which DOES predict:

  • Job performance (especially Conscientiousness)
  • Academic achievement
  • Relationship satisfaction
  • Mental health outcomes
  • Longevity

MBTI’s failure to predict real-world outcomes is a fundamental scientific failure.

Scientific Problem #3: The Forer Effect (Barnum Effect)

Here’s an experiment:

Read this personality description and rate how well it describes you (1-5):

“You have a great need for other people to like and admire you. You have a tendency to be critical of yourself. You have a great deal of unused capacity which you have not turned to your advantage. While you have some personality weaknesses, you are generally able to compensate for them. Disciplined and self-controlled outside, you tend to be worrisome and insecure inside.”

Most people rate this 4 or 5 out of 5.

Here’s the catch: This is a generic statement given to everyone in psychology experiments. It describes no one specifically.

This is the Forer Effect (also called the Barnum Effect, after P.T. Barnum’s “a sucker is born every minute”).

People rate vague, generally positive statements as highly accurate descriptions of their unique personality.

MBTI profiles are loaded with Forer Effect statements:

“INTJs are independent thinkers who value logic.” (Who doesn’t think they value logic?)

“ENFPs are creative people who care about others.” (Most people see themselves as creative and caring.)

“ISTJs are detail-oriented and responsible.” (Everyone thinks they’re responsible in their own way.)

The profiles feel personal, but they’re actually generic enough to apply to almost anyone.

Scientific Problem #4: Missing the Actual Big Picture

Decades of research in personality psychology have converged on a different model: The Big Five (or Five Factor Model).

The Big Five emerged from data, not theory. Researchers analyzed thousands of personality descriptors and found they clustered into five broad dimensions:

1. Openness to Experience

  • Creativity, curiosity, willingness to try new things
  • vs. Preference for routine and convention

2. Conscientiousness

  • Organization, responsibility, self-discipline
  • vs. Spontaneity and flexibility

3. Extraversion

  • Sociability, assertiveness, energy from others
  • vs. Preference for solitude and reflection

4. Agreeableness

  • Compassion, cooperation, trust
  • vs. Skepticism and competitiveness

5. Neuroticism (Emotional Stability)

  • Anxiety, mood swings, emotional reactivity
  • vs. Calm and emotional resilience

Unlike MBTI:

  • High test-retest reliability (your scores stay relatively stable)
  • Predicts real-world outcomes (job performance, relationship satisfaction, health)
  • Cross-cultural validity (found across cultures and languages)
  • Biological basis (correlates with brain structure and genetics)
  • Continuous dimensions (not binary categories)

MBTI ignores Neuroticism entirely. It conflates and confuses other dimensions. It creates artificial categories where reality is continuous.

Why does MBTI persist despite being scientifically inferior?

Because Big Five descriptions are less flattering and more complex:

“You score high in Neuroticism” sounds worse than “You’re an INFP, a thoughtful idealist!”

But truth isn’t always comfortable.

The Enneagram: Ancient Wisdom or Modern Myth?

The Enneagram has become wildly popular, especially in Christian and therapeutic communities.

It divides people into nine types:

  1. The Perfectionist
  2. The Helper
  3. The Achiever
  4. The Individualist
  5. The Investigator
  6. The Loyalist
  7. The Enthusiast
  8. The Challenger
  9. The Peacemaker

Each type has wings, stress/growth directions, and integration levels.

The Origins: Even Murkier Than MBTI

The Enneagram’s history is… complicated.

Proponents claim ancient roots (Pythagorean, Kabbalistic, Sufi), but historians find no evidence of the personality typing system before the 20th century.

It was developed by:

  • George Gurdjieff (Armenian mystic) in the early 1900s—but his version was about cosmology, not personality
  • Oscar Ichazo (Bolivian spiritual teacher) in the 1960s—added personality types
  • Claudio Naranjo (Chilean psychiatrist) in the 1970s—brought it to the U.S. and linked it to psychology

So the “ancient wisdom” is actually a 1960s invention with New Age spiritual roots.

Scientific credentials? Even worse than MBTI.

Scientific Problem: Virtually Zero Peer-Reviewed Research

Search academic psychology databases for “Enneagram” and you’ll find:

  • Very few peer-reviewed studies
  • Most research is in Christian counseling journals, not psychology journals
  • No large-scale validation studies
  • No established psychometric properties
  • No standardized test (multiple versions exist with different questions)

The Enneagram exists almost entirely outside the scientific community.

This doesn’t automatically make it worthless—but it means we have no rigorous evidence that it:

  • Measures stable traits
  • Predicts behavior
  • Is more accurate than chance
  • Is more useful than existing validated measures

The Appeal: Depth and Spiritual Meaning

So why do people love the Enneagram?

1. It feels deeper than MBTI

  • Addresses motivation, fear, and desire
  • Includes growth and stress dynamics
  • Describes unhealthy and healthy manifestations

2. It integrates spiritual development

  • Not just personality description, but path to growth
  • Resonates with people seeking meaning
  • Connects to contemplative traditions

3. The descriptions are rich and specific

  • Reading your type feels revelatory
  • (Also prime for Forer Effect)

My experience:

I tested as a Type 4 (The Individualist). The description was eerily accurate:

  • Feeling fundamentally different from others
  • Longing for what’s missing
  • Creativity and emotional depth
  • Fear of being ordinary

It gave me a framework to understand patterns in my life.

But here’s what bothers me:

When I read Type 5 (The Investigator), I also resonated strongly:

  • Withdrawing to conserve energy
  • Desire to understand the world
  • Detachment and observation
  • Fear of being overwhelmed

And Type 9 (The Peacemaker):

  • Avoiding conflict
  • Merging with others’ agendas
  • Difficulty knowing what I want
  • Fear of disconnection

I could convince myself I’m any of these types.

Without rigorous empirical validation, I’m just picking the description that resonates most today, in this mood, with this mindset.

That’s not personality assessment. That’s storytelling.

DiSC (Dominance, Influence, Steadiness, Conscientiousness)

Origins: William Moulton Marston (1920s)—also the creator of Wonder Woman, interestingly

Scientific Status: Better than MBTI, not as good as Big Five

  • Some research support
  • Used primarily in corporate settings
  • Simpler model (4 dimensions)
  • Decent for team communication, weak for prediction

Bottom line: Not terrible, but Big Five is better if you want real science

StrengthsFinder (CliftonStrengths)

Origins: Gallup Organization (2001)

Scientific Status: Mixed

  • Based on research by Donald Clifton
  • Focuses on strengths (34 themes), not personality
  • Some research validation
  • Proprietary, so hard to independently verify
  • More useful for development than assessment

Bottom line: Better than MBTI, useful for coaching, but limited empirical support

16 Personalities (Free Online Test)

Origins: Based on MBTI + Big Five hybrid

Scientific Status: Confusing mess

  • Claims to be based on Big Five
  • Uses MBTI letter system
  • Not scientifically validated
  • Very popular online
  • Basically MBTI with a facelift

Bottom line: Same problems as MBTI, despite Big Five branding

The Real Harm of Pseudoscientific Personality Tests

“It’s just for fun. What’s the harm?”

I used to think this too. But there are real costs:

Harm #1: Limiting Yourself

“I’m an introvert, so I can’t be good at public speaking.”

“I’m a Type 9, so I’ll never be assertive.”

“I’m not a ‘people person,’ so I won’t pursue management.”

Personality labels become excuses to avoid growth.

Yes, we have predispositions. But personality is more fluid and context-dependent than these tests suggest.

Research shows:

  • Personality changes across the lifespan (we generally become more agreeable and conscientious with age)
  • Behavior varies dramatically by situation
  • Skills can be learned even if they don’t come naturally

Labeling yourself creates a fixed mindset that can prevent development.

Harm #2: Misunderstanding Others

“He’s an ESTJ, so he only cares about rules and efficiency.”

Personality types become stereotypes.

You stop seeing the individual and start seeing the label. You assume you know how someone thinks, what motivates them, what they’re capable of.

This reduces empathy and creates rigid expectations.

Harm #3: Bad Hiring and Career Decisions

Companies spend millions on MBTI for hiring, team building, and leadership development.

But MBTI doesn’t predict job performance.

Using it for hiring is:

  • Wasteful (spending money on invalid tools)
  • Potentially discriminatory (selecting for “types” rather than ability)
  • Misleading (giving false confidence in decisions)

Career counselors who guide people based on MBTI types may steer them away from fulfilling paths because “that’s not your type.”

Harm #4: Relationship Myths

“INFPs and ENTJs aren’t compatible.”

“I’m a Type 8, so I need a Type 2 partner.”

There’s no evidence that personality type predicts relationship compatibility.

Successful relationships depend on:

  • Communication skills
  • Emotional regulation
  • Shared values
  • Commitment
  • Conflict resolution

Not your four-letter code.

Harm #5: Reinforcing the Illusion of Self-Knowledge

The biggest harm is subtle:

Personality tests give you the feeling of understanding yourself without actually doing the hard work of self-reflection.

You take a 10-minute quiz, read a description, and feel like you’ve unlocked deep self-knowledge.

But real self-understanding requires:

  • Honest reflection on patterns
  • Feedback from others
  • Understanding your history and context
  • Recognizing how you change across situations
  • Ongoing curiosity about yourself

A personality test is a shortcut that bypasses actual insight.

What Actually Works: Science-Based Self-Understanding

If MBTI and Enneagram are flawed, what should you use instead?

Option 1: The Big Five (OCEAN)

If you want a scientifically validated personality assessment, use the Big Five.

Free, validated versions:

  • IPIP-NEO (120 questions, very thorough)
  • BFI-2 (60 questions, shorter)
  • Mini-IPIP (20 questions, quick)

These will give you scores on five dimensions, showing where you fall on continuous scales.

How to use the results:

Don’t treat them as fixed identity. Instead:

Conscientiousness (Low):

  • “I tend toward spontaneity and flexibility. For projects requiring sustained organization, I should build external systems (calendars, reminders, accountability partners).”

Neuroticism (High):

  • “I experience emotions intensely and may be prone to anxiety. I should prioritize stress management, therapy, and healthy coping mechanisms.”

Openness (High):

  • “I love novelty and ideas. I thrive in creative work but may struggle with routine. I need both stimulation and structure.”

Use the results as data, not destiny.

Option 2: Values Assessment

Instead of personality, explore your values—what actually matters to you.

Good frameworks:

Schwartz Theory of Basic Values:

  • Achievement
  • Power
  • Security
  • Conformity
  • Tradition
  • Benevolence
  • Universalism
  • Self-Direction
  • Stimulation
  • Hedonism

Acceptance and Commitment Therapy (ACT) Values Work:

  • Identify what you care about across life domains
  • Notice when you’re acting consistent with values
  • Recognize values-behavior gaps

Why values matter more than personality:

  • Values guide decisions more reliably than traits
  • Values are chosen, not just discovered
  • Values provide direction for growth
  • Values don’t limit—they inspire

Option 3: Behavioral Patterns Analysis

Instead of asking “What type am I?”, ask:

“What patterns do I notice in my behavior?”

Useful questions:

Energy:

  • When do I feel energized vs. drained?
  • What activities or people boost my mood?
  • What situations deplete me?

Motivation:

  • What makes me feel alive and engaged?
  • When do I lose track of time?
  • What accomplishments feel most meaningful?

Stress:

  • How do I react under pressure?
  • What triggers anxiety or frustration?
  • What helps me regulate difficult emotions?

Relationships:

  • What do I value in friendships?
  • What communication styles work for me?
  • Where do I tend to have conflict?

Decision-making:

  • How do I approach major choices?
  • Do I decide quickly or slowly?
  • What factors carry the most weight?

Track these over time in a journal. Look for patterns. Get feedback from people who know you well.

This is harder than taking a quiz. But it’s actual self-knowledge.

Option 4: Therapy and Coaching

A skilled therapist or coach can help you understand yourself better than any test.

What they offer that tests can’t:

  • Personalized exploration of your history
  • Identification of unconscious patterns
  • Reflection on how context shapes you
  • Challenge to your self-perceptions
  • Accountability for growth

Good therapy explores:

  • Attachment patterns (how early relationships shape current ones)
  • Defense mechanisms (how you protect yourself)
  • Core beliefs (assumptions about yourself, others, the world)
  • Meaning-making (how you interpret experiences)

This is deep, individualized work that no standardized test can replicate.

Option 5: 360-Degree Feedback

Ask people who know you well:

“How would you describe me?” “What do you see as my strengths?” “Where do you see me struggling?” “How do I show up in relationships?”

This is uncomfortable. But it reveals:

  • Blind spots (things you don’t see about yourself)
  • Consistency (or inconsistency) in how you’re perceived
  • Gaps between intention and impact

The difference between how you see yourself and how others see you is often where the most growth happens.

Can Personality Tests Still Be Useful?

After all this criticism, you might wonder: “Should I throw out every personality test?”

Not necessarily.

Here’s my nuanced take:

Legitimate Uses:

1. Conversation Starter

If discussing your “MBTI type” with a friend leads to genuine conversation about values, preferences, and behavior—great. The label is just scaffolding for deeper dialogue.

2. Framework for Reflection

If reading an Enneagram description prompts you to reflect on patterns, motivations, and growth—wonderful. You’re using it as a mirror, not a rulebook.

3. Shared Language in Teams

If a team uses DiSC to discuss communication preferences—fine, as long as they don’t treat it as scientific fact or limit people based on “type.”

4. Personal Entertainment

If taking personality quizzes is fun and you don’t take them seriously—go ahead. We all enjoy a bit of self-indulgence.

Illegitimate Uses:

1. Hiring Decisions

Don’t use MBTI or Enneagram to screen candidates. Use structured interviews, work samples, and validated assessments.

2. Limiting Yourself or Others

Don’t use type as an excuse not to grow. “I’m an introvert” doesn’t mean you can’t develop public speaking skills.

3. Predicting Compatibility

Don’t base relationship decisions on personality type. Compatibility is complex and multifaceted.

4. Claiming Scientific Authority

Don’t say “studies show” about MBTI. They don’t. Be honest about what these tools are—popular frameworks with limited scientific support.

My Personal Synthesis: Using Tests Wisely

Here’s how I think about personality tests now:

MBTI/Enneagram: Mythology, not science

I don’t take them seriously as assessments, but I appreciate the archetypes and frameworks they provide. Reading about different types can spark self-reflection and empathy for different perspectives.

Big Five: Useful data point

When I took a validated Big Five test, I learned:

  • High Openness (I love novelty and ideas—checks out)
  • Moderate Conscientiousness (I need external structure to stay organized—accurate)
  • Low-Moderate Extraversion (I’m ambiverted—context matters)
  • Moderate Agreeableness (I can be collaborative or competitive—depends on situation)
  • Moderate Neuroticism (I experience anxiety but also resilience—both are true)

These aren’t revelations, but they’re accurate descriptions. They give me language for tendencies without boxing me in.

Values: Most useful

Understanding what I care about (learning, autonomy, impact, connection, creativity) guides my decisions better than any personality label.

Behavioral patterns: Where the real work happens

Noticing when I procrastinate, what triggers anxiety, how I respond to criticism, what energizes me—this is ongoing, contextual, and deeply personal.

No test can replace this work.

Final Thoughts: The Complexity of Being Human

Personality tests promise simple answers to complex questions:

“Who am I?” “Why do I act this way?” “How should I live?”

But humans resist categorization.

You’re not a type. You’re a dynamic, context-sensitive, ever-evolving system of:

  • Genetics
  • Early experiences
  • Cultural influences
  • Current environment
  • Chosen values
  • Learned skills
  • Moment-to-moment states

Some aspects are stable (you probably won’t fundamentally change your temperament). Some are fluid (your behavior varies wildly by context). Some are chosen (you can decide what you value and how you grow).

Personality tests can be a starting point for self-reflection.

But they’re a terrible endpoint.

Don’t let a four-letter code or a number from 1-9 become your identity. You’re far too complex, contradictory, and interesting for that.

The real work of self-understanding is harder, slower, and less satisfying than taking a quiz.

But it’s also deeper, truer, and more transformative.

So by all means, take the personality test. Read the description. Enjoy the moment of recognition.

Then ask: “What does this make me curious about? What should I explore further? How can I grow?”

And don’t stop there.

What’s your relationship with personality tests? Have they helped or limited you? I’d love to hear your experiences.