Walk into any bookstore's self-help section and you'll find dozens of books promising to reveal your "true personality." Take any online quiz and you'll be sorted into a type, category, or color. Personality frameworks are everywhere.
But how much of this is actually science? What do researchers who study personality for a living actually know? And how should you think about the personality assessments you encounter?
Let's dig into the real science of personality.
What Is Personality, Really?
Before we can study personality, we need to define it. Researchers generally agree on something like this: personality consists of the relatively stable patterns of thinking, feeling, and behaving that distinguish individuals from one another.
A few key points:
"Relatively stable" — Personality isn't fixed in stone, but it doesn't change dramatically day to day. Your personality at 30 will be recognizably related to your personality at 20, even if some things have shifted.
"Patterns" — We're talking about tendencies and averages, not every single action. An introvert can give a great speech; an agreeable person can have a sharp conflict. Personality describes the general trend.
"Distinguish individuals" — Personality is about differences. What makes you different from other people in consistent, meaningful ways?
The Big Five: What We Know Best
If there's one thing personality researchers have established with high confidence, it's the existence of the Big Five personality traits (also called the Five-Factor Model or OCEAN):
Openness to Experience
People high in Openness are curious, imaginative, and drawn to new ideas and experiences. People low in Openness prefer the familiar, the practical, and the concrete.
Conscientiousness
High Conscientiousness means organized, disciplined, and goal-oriented. Low Conscientiousness means more spontaneous, flexible, and sometimes disorganized.
Extraversion
High Extraversion means sociable, assertive, and energized by external stimulation. Low Extraversion (Introversion) means more reserved, reflective, and needing less stimulation.
Agreeableness
High Agreeableness means cooperative, compassionate, and trusting. Low Agreeableness means more competitive, skeptical, and challenging.
Neuroticism
High Neuroticism means prone to negative emotions like anxiety, sadness, and irritability. Low Neuroticism means more emotionally stable and resilient.
Why Scientists Trust the Big Five
The Big Five didn't emerge from someone's theory about how personality "should" work. It emerged from data.
The Lexical Hypothesis
The original reasoning was simple: if a personality trait matters to humans, we'll have words for it. Researchers analyzed the personality-describing words in English (and later, many other languages) and used factor analysis to find the underlying dimensions.
Remarkably, five factors kept emerging. Whether you analyze American college students or elderly Germans or rural Filipinos, you find something very close to the Big Five.
Cross-Cultural Replication
A landmark study by McCrae and Costa examined personality data from 50 cultures across 6 continents. The five-factor structure appeared in all of them. This suggests we're measuring something real about human nature, not just artifacts of Western culture.
Predictive Validity
The real test of any psychological construct: does it predict anything that matters? The Big Five passes this test impressively.
Research has linked Big Five traits to:
- Job performance: Conscientiousness predicts success across virtually all occupations
- Relationship satisfaction: Agreeableness and low Neuroticism predict happier relationships
- Health outcomes: Conscientiousness predicts longevity; Neuroticism predicts health problems
- Academic achievement: Conscientiousness and Openness predict better grades
- Mental health: Neuroticism is the strongest personality predictor of depression and anxiety
Biological Correlates
Brain imaging studies have found correlations between Big Five traits and brain structure:
- Extraversion correlates with volume in reward-processing regions
- Neuroticism correlates with regions involved in threat detection
- Conscientiousness correlates with prefrontal regions involved in planning
This doesn't prove personality is "hardwired," but it suggests we're measuring something with biological reality.
The MBTI Debate: Popular vs. Scientific
Now we get to more controversial territory. The Myers-Briggs Type Indicator (MBTI) is by far the most popular personality assessment worldwide. Over 2 million people take it annually. Fortune 500 companies use it for team building. It's a cultural phenomenon.
But what does the science say?
The Criticisms
Type vs. Trait: The MBTI categorizes people into 16 discrete types. But research shows that the underlying dimensions (like introversion-extraversion) are continuous, not categorical. Most people fall in the middle, not at the extremes. Forcing them into types may distort reality.
Test-Retest Reliability: Studies have found that 50% of people get a different type when retaking the MBTI after just five weeks. This is concerning—your "true type" shouldn't flip that easily.
Limited Predictive Validity: The MBTI doesn't predict job performance, academic success, or other outcomes as well as the Big Five does. Some studies find essentially no predictive validity once you control for other factors.
The Defense
It Captures Something Real: MBTI dimensions do correlate moderately with Big Five traits. The correlation isn't perfect, but it's there. MBTI isn't completely invalid—it's measuring something.
Practical Utility: Even if MBTI lacks scientific precision, many people find it useful for self-reflection, team communication, and personal development. Utility and validity aren't the same thing.
Implementation Matters: The MBTI's creators intended it for self-exploration, not hiring decisions or performance prediction. Misuse doesn't invalidate proper use.
A Balanced View
The MBTI shouldn't be used for high-stakes decisions like hiring or school admissions. But as a tool for self-reflection and a framework for discussing personality differences? It can be valuable—as long as you hold your type loosely and recognize its limitations.
Beyond the Big Five: What Else Matters?
The Big Five is the best-validated model, but it doesn't capture everything. Some important constructs beyond the Big Five:
Character Strengths
The Values in Action (VIA) Classification identifies 24 character strengths like curiosity, courage, fairness, and hope. These are more specific than Big Five traits and can guide personal development.
Motives and Values
What you want (motives) and what you believe is important (values) aren't the same as personality traits, but they're equally important for understanding a person. Someone might be introverted but highly ambitious, or extraverted but values humility.
Dark Triad
Research has identified three "dark" personality traits: Narcissism, Machiavellianism, and Psychopathy. While most personality research focuses on normal variation, these traits capture tendencies that can be harmful to self and others.
Emotional Intelligence
Whether EQ is truly a form of "intelligence" is debated, but the underlying abilities—perceiving emotions, using emotions to facilitate thinking, understanding emotions, and managing emotions—are measurable and predictive of outcomes.
How to Evaluate Personality Assessments
With countless personality tests available, how do you know which ones to take seriously?
Ask About Validity Evidence
Construct validity: Does the test measure what it claims to measure? Look for correlations with other established measures.
Predictive validity: Does the test predict anything meaningful? Look for studies linking test results to outcomes.
Reliability: Does the test give consistent results? Look for test-retest reliability data.
Legitimate assessments will have published research supporting their validity. If you can't find any studies, be skeptical.
Consider the Source
Assessments developed by research psychologists at universities, with peer-reviewed publications, are more trustworthy than those created by commercial companies with no academic backing.
Watch for Red Flags
- Proprietary "secrets": Real science is public. If the creators won't share how their test works, that's concerning.
- Extraordinary claims: If a test claims to predict everything from career success to romantic compatibility with 99% accuracy, it's lying.
- One-size-fits-all interpretation: Good assessments acknowledge complexity and individual variation.
- No wrong answers... but also no validation: Tests that just affirm everything without evidence aren't science.
Personality Is Not Destiny
Perhaps the most important lesson from personality research: traits are tendencies, not prisons.
Traits can change: While personality is relatively stable, it does shift over time. Most people become more conscientious and less neurotic as they age. Therapy and intentional effort can accelerate change.
Situations matter: Behavior is a product of personality AND situation. An introvert can become energized at a small gathering of close friends. An agreeable person can fight fiercely for a cause they believe in.
Strategies can compensate: Knowing your tendencies lets you develop strategies to work with or around them. A disorganized person can use external systems; an anxious person can practice coping techniques.
The goal of understanding personality isn't to put yourself in a box. It's to understand your patterns so you can work with them skillfully.
The Future of Personality Science
Personality psychology continues to evolve. Current frontiers include:
Computational Approaches: Analyzing digital footprints (social media, smartphones) to assess personality passively. This raises fascinating possibilities and serious ethical concerns.
Neuroscience Integration: Understanding the brain mechanisms underlying personality at increasingly fine-grained levels.
Dynamic Models: Moving beyond static trait descriptions to understand how personality unfolds moment-to-moment and across situations.
Cross-Cultural Refinement: Testing whether Western-developed models truly capture universal human nature or miss important variation.
Taking Personality Seriously (But Not Too Seriously)
Personality psychology offers genuine insights. The Big Five is a robust finding. Knowing your traits can help you make better decisions about careers, relationships, and self-development.
But personality is one lens among many for understanding yourself and others. It doesn't capture everything. Hold your results as useful hypotheses, not unchangeable truths. Use assessments for reflection and growth, not for limiting yourself or judging others.
The most valuable outcome of exploring your personality isn't a label—it's the increased self-awareness that helps you live more intentionally.
Ready to explore your personality with a scientifically-informed assessment? Our tests draw on established research while providing personalized insights for your growth journey.