Podcasts > Stuff You Should Know > Selects: How Personality Tests Work

Selects: How Personality Tests Work

By iHeartPodcasts

Stuff You Should Know examines personality tests, focusing on the Myers-Briggs Type Indicator (MBTI). The hosts trace the test's development by Katharine Cook Briggs and Isabel Briggs Myers after World War II, its widespread adoption in corporate America, and the certification process required to administer it today.

The hosts explore criticisms of the MBTI, including its tendency to categorize people into rigid types rather than recognizing personality as a spectrum. They discuss how the MBTI differs from scientifically validated tests like the "Big Five," and address concerns about using personality tests for employment decisions and legal proceedings, despite warnings from the MBTI's creators about such applications.

Listen to the original

Selects: How Personality Tests Work

This is a preview of the Shortform summary of the Nov 15, 2025 episode of the Stuff You Should Know

Sign up for Shortform to access the whole episode summary along with additional materials like counterarguments and context.

Selects: How Personality Tests Work

1-Page Summary

History and Development of Myers-Briggs Type Indicator (MBTI)

After World War II, Katharine Cook Briggs and Isabel Briggs Myers developed the MBTI, drawing inspiration from Carl Jung's theories. As Chuck Bryant explains, they modified Jung's work to better suit the modern American workforce, particularly focusing on helping women find suitable jobs in the post-war era. The test categorizes people into 16 personality types using four dichotomous scales.

The MBTI gained significant traction in corporate America, with Josh Clark noting that by the 1990s, 89 of the Fortune 100 companies were using it. Today, administering the test requires certification through CPP, involving a four-day training program costing $1,500-$1,600.

Critiques of the MBTI and Other Personality Tests

Bryant and Clark highlight several criticisms of the MBTI, particularly its tendency to box people into rigid categories rather than recognizing personality as a spectrum. They point out that preferences often overlap MBTI dichotomies, and a person's type can change with different situations.

The hosts emphasize that the MBTI lacks scientific validity compared to other psychological tools, as it's based primarily on personal observations rather than empirical research. They compare it to astrology, noting how both tend to present results in an unfailingly positive light.

Psychometrics and Personality Test Validity

While some personality tests, like the "Big Five," have scientific backing, Clark and Bryant discuss how all tests struggle to capture human complexity. They explain that personality is shaped by numerous factors beyond innate traits, including motivation, emotion, social roles, and experiences.

The hosts note that more legitimate psychometric tests attempt to overcome subjectivity by asking questions in various forms and interpreting results on a spectrum. However, Bryant questions the overall meaningfulness of these tests, given the difficulty in establishing what's considered "normal."

Despite warnings from the MBTI's creators, many corporations use the test for employment decisions, including hiring, firing, and promotions. Clark points out that serious psychologists view the MBTI with skepticism, particularly regarding its use in professional settings. The test's application has extended into legal proceedings, raising concerns about the impact of subjective personality assessments on people's lives.

1-Page Summary

Additional Materials

Counterarguments

  • The MBTI's categorization into 16 personality types is based on dichotomies that may not capture the fluidity of human personality, but proponents argue that these categories provide a useful framework for understanding and discussing personality differences.
  • While the MBTI may lack empirical research compared to other psychological tools, supporters claim that it has practical value for self-reflection and team building, even if it should not be used as a sole decision-making tool in corporate settings.
  • Critics argue that the MBTI presents results too positively, akin to astrology, but advocates suggest that this positive framing can be beneficial for personal development by focusing on strengths rather than weaknesses.
  • Although the MBTI is criticized for its lack of scientific validity, some argue that it still offers a common language for discussing personality and can be a starting point for more in-depth psychological analysis.
  • The requirement for certification to administer the MBTI could be seen as a barrier to access, but it can also be viewed as a means to ensure that those interpreting the results are trained and knowledgeable about the tool.
  • The use of the MBTI in employment decisions is controversial, but some argue that when used ethically and as one of multiple assessment tools, it can contribute to a better understanding of employee dynamics and job fit.
  • The application of the MBTI in legal contexts is contentious, but some might argue that it can provide insights into an individual's behavior or preferences, as long as it is not the sole factor in making legal decisions.

Actionables

  • You can explore your own personality by journaling daily reflections on your behaviors and feelings in different situations to identify patterns without relying on tests like the MBTI. By tracking your reactions and decisions in a variety of contexts over time, you'll gain a more nuanced understanding of your personality traits that goes beyond rigid categories.
  • Develop a personal growth plan by identifying skills and experiences you want to acquire, rather than focusing on fitting into a specific personality type. For example, if you notice you're uncomfortable in social situations, instead of labeling yourself as introverted, set a goal to attend a certain number of social events each month to build your confidence.
  • When considering career moves or personal decisions, consult with a diverse group of friends or colleagues to get a broad range of perspectives. This approach acknowledges the complexity of personality and can provide insights that a personality test may not, helping you make choices that are informed by real-world experiences and advice.

Get access to the context and additional materials

So you can understand the full picture and form your own opinion.
Get access for free
Selects: How Personality Tests Work

History and Development of Myers-Briggs Type Indicator (MBTI)

The Myers-Briggs Type Indicator (MBTI), a personality assessment tool, was developed in the mid-20th century and has significantly influenced both the workplace and popular understanding of personality.

MBTI Was Developed In the 1940s and 1950s by Katharine Briggs and Isabel Myers, Inspired by Jung's Ideas

After World War II, Katharine Cook Briggs and her daughter Isabel Briggs Myers developed the MBTI, having been influenced by the works of Carl Jung. Chuck Bryant explains that Briggs and Myers built upon and modified Jung's theories, even choosing to omit much of his work on the unconscious as they felt it was ill-suited for the modern American workforce. Briggs and Myers dedicated decades to develop the MBTI, but interestingly, they established the personality types first and then worked backward to create a test that could identify these types.

During their research and development phase, they administered the MBTI to about 5,000 medical students from George Washington University and observed their career paths. This long-term study was influential in refining the MBTI over time.

MBTI: Created by Briggs and Myers to Help Women Find WWII Jobs, Categorizing 16 Personality Types

The MBTI was particularly motivated by the need to integrate women into the workforce following the post-World War II era. It was crafted to help determine the types of jobs for which women might be best suited and most likely to enjoy. The test was designed to categorize individuals into one of 16 personality types using four dichotomous scales: introverted or extroverted, sensing or intuition, thinking or feeling, and judging or perceiving.

MBTI Spread In Corporate America: 89 of the Fortune 100 Used It By the 1990s

By the 1990s, the MBTI had garnered substantial traction in the corporate space, as Josh Clark reveals that 89 of the Fortune 100 companies employed the MBTI. The test’s popularity surged in the '70s after Myers-Briggs switched to CPP as i ...

Here’s what you’ll find in our full summary

Registered users get access to the Full Podcast Summary and Additional Materials. It’s easy and free!
Start your free trial today

History and Development of Myers-Briggs Type Indicator (MBTI)

Additional Materials

Counterarguments

  • The scientific validity of the MBTI has been questioned by psychologists and researchers, as it lacks empirical support and is not widely endorsed in the scientific community.
  • The dichotomous nature of the MBTI scales may oversimplify human personality, which is more complex and nuanced than the binary options suggest.
  • The MBTI's reliability has been criticized; some studies have shown that as many as 50% of individuals receive a different type upon retaking the test.
  • The MBTI was developed with a specific cultural context in mind, which may limit its applicability and relevance across diverse global workforces.
  • The use of the MBTI in hiring and employment decisions can be controversial, as it may lead to pigeonholing or discrimination against certain personality types.
  • The requirement for expensive certification to administer the MBTI can be seen as a barrier to access and may contribute to the perception of the MBTI as a commercial product rather than a scientific tool.
  • The MBTI's focus on positive traits for each type may contribute to a lack of critical feedback, which is essential for personal and professional development.
  • The ...

Actionables

  • Explore your own personality by journaling your reactions to daily events, focusing on the four dichotomous scales of the MBTI to gain self-awareness without taking the test. For example, after a meeting, write down whether you felt energized or drained (introverted/extroverted), focused on details or the big picture (sensing/intuition), made decisions based on logic or emotion (thinking/feeling), and preferred structure or spontaneity (judging/perceiving).
  • Create a personal development plan by identifying skills and interests that align with your self-assessed personality traits, then set goals to pursue careers or hobbies that fit those traits. If you find you're more feeling-oriented, consider volunteering or careers in counseling, whereas if you're more thinking-oriented, you might explore fields like technology or analytics.
  • Use the concept of personality typ ...

Get access to the context and additional materials

So you can understand the full picture and form your own opinion.
Get access for free
Selects: How Personality Tests Work

Critiques of the Mbti and Other Personality Tests

Chuck Bryant and Josh Clark explore the limitations and criticism surrounding personality tests like the Myers-Briggs Type Indicator (MBTI), challenging their accuracy and scientific basis.

Mbti Criticized For Boxing People Into Types, Not Recognizing Personality Spectrum

Preferences Overlap Mbti Dichotomies; Type Changes With Situation

Chuck Bryant and Josh Clark contend that human personality is too complex to be confined to a single category, as MBTI and similar tests attempt to do. During their discussion, Clark voices his skepticism about defining a person by one personality type, given that individuals can exhibit traits from different types within even a single day or situation. Bryant highlights that one major critique of personality tests is the oversimplification of the vast array of human personalities.

The MBTI in particular, which is based on Carl Jung's theories, is criticized for categorically boxing people into types instead of allowing for a personality spectrum. The hosts point out the intrinsic issue with this approach, emphasizing that personality traits aren't black and white and that people often find themselves in the middle of the MBTI's dichotomies.

Mbti Is Based On Jung, Briggs, and Myers' Theories, Not Rigorous Research

Mbti Lacks Validity and Reliability Compared To Other Tools

The hosts outline that the MBTI lacks validity and reliability when compared to other psychological tools favored by psychologists, such as the "big five" personality traits. They discuss the foundations of the MBTI, pointing out that it stems from personal observations and theories by Jung, Briggs, and Myers rather than empirical research. The scientific community, they note, has largely rejected Jung's ideas, with the implication being that any tool based on his teachings, such as the MBTI, is also discredited.

Bryant and Clark dive into the MBTI's creation, describing it as problematic due to its lack of rigorous scientific data. They compare the MBTI to astrology, arguing that like horoscopes, it presents results in an unfailingly positive light, which may skew how individuals perce ...

Here’s what you’ll find in our full summary

Registered users get access to the Full Podcast Summary and Additional Materials. It’s easy and free!
Start your free trial today

Critiques of the Mbti and Other Personality Tests

Additional Materials

Counterarguments

  • MBTI is intended as a tool for self-reflection and personal growth, not a definitive measure of personality.
  • Some argue that the MBTI's categories can help individuals understand their own preferences and the preferences of others, potentially improving communication and interpersonal relationships.
  • The MBTI's dichotomies reflect Jung's theory of psychological types, which some practitioners find useful in a variety of contexts, including counseling and organizational development.
  • While the MBTI may not be a scientifically rigorous tool, it can still offer value in non-clinical settings, such as team-building or personal development workshops.
  • The MBTI's positive framing of personality types can be empowering for individuals, helping them to focus on strengths and areas for growth rather than pathologizing their traits.
  • Some proponents of the MBTI argue that it has face validity, meaning that many individuals find the descriptions of their type to resonate with their self-perception.
  • The MBTI's popularity and widespread use suggest that it meets a need for a simple, accessible framework for thinking about personality differences.
  • The MBTI's lack of scientific rigor does not necessarily invalidate the personal insights individuals may gain from it.
  • The MBTI may serve as a starting point for more in-d ...

Actionables

  • You can explore the fluidity of your personality by keeping a daily journal to track how your behaviors and attitudes shift in different contexts. Note down situations where you felt you exhibited traits that don't align with your perceived personality type. For example, if you consider yourself an introvert but find yourself enjoying and seeking out social interactions in certain settings, document these instances to understand the spectrum of your personality better.
  • Develop a personalized set of self-reflection questions that go beyond binary choices to gauge your personality traits. Instead of asking "Am I introverted or extroverted?" frame questions like "In what situations do I feel energized by social interactions, and when do I prefer solitude?" Use these questions regularly to self-assess and recognize the nuances in your behavior that standardized tests may not capture.
  • Create a 'personality mood board ...

Get access to the context and additional materials

So you can understand the full picture and form your own opinion.
Get access for free
Selects: How Personality Tests Work

Psychometrics and Personality Test Validity

The legitimacy and effectiveness of personality tests are heavily scrutinized in light of their historical context and the complexities of the human psyche.

Criticism of Personality Tests For Subjectivity and Mislabeling

Personality tests, such as the Rorschach test, have been criticized for their subjectivity and potential to mislabel individuals. A study in 2000, given to mentally sound elementary school children, resulted in a high percentage being mislabeled as borderline psychotic because of their Rorschach test results. This instance underscores serious concerns about the accuracy of such tests and suggests that they may cause more harm than good.

Clark and Bryant discuss the historical practice of personality testing, which has often entailed categorizing people into fixed types, such as the four humors or Carl Jung's personality types. These categorical approaches are now being questioned for failing to capture the multifaceted and dynamic nature of human personality.

Some Tests Like "Big Five" Have Science Backing, but all Struggle to Capture Human Complexity

The "Big Five" personality traits—extraversion, agreeableness, openness to experience, conscientiousness, and neuroticism—are recognized in scientific literature and considered more valid by psychologists than other tests, like the Myers-Briggs Type Indicator (MBTI). The conversation acknowledges the Big Five as an attempt by psychologists to quantify personality traits more reliably.

Personality Is Shaped by More Than Innate Traits: Motivation, Emotion, Social Roles, Experiences

Nevertheless, personality is recognized as being shaped by a multitude of factors, including motivation, emotion, social roles, and personal experiences, not just innate traits. Psychologists recognize that there is more to an individual than just the Big Five traits, and that understanding someone’s personality requires a more in-depth exploration, including their motivations, emotions, attitudes, abilities, self-concepts, social roles, autobiographical memories, and life stories.

Psychometric tests that try to overcome su ...

Here’s what you’ll find in our full summary

Registered users get access to the Full Podcast Summary and Additional Materials. It’s easy and free!
Start your free trial today

Psychometrics and Personality Test Validity

Additional Materials

Clarifications

  • The Rorschach test is a psychological assessment where individuals interpret inkblots. It aims to reveal underlying thoughts, feelings, and personality traits through their perceptions. Developed by Hermann Rorschach in the 1920s, it is used to explore unconscious aspects of the mind. However, its interpretation is highly subjective and controversial.
  • The "four humors" theory is an ancient medical concept that suggests human health and personality are governed by four bodily fluids: blood, phlegm, black bile, and yellow bile. Each humor was believed to correspond to specific temperaments: sanguine, phlegmatic, melancholic, and choleric. Imbalances in these humors were thought to affect both physical health and personality traits. This theory was widely accepted in Western medicine until the 19th century but is now considered outdated.
  • Carl Jung's personality types are based on psychological functions and attitudes, dividing people into categories like introversion vs. extraversion and thinking vs. feeling. These types aim to describe how individuals perceive the world and make decisions. Jung's theory influenced many modern personality assessments, including the Myers-Briggs Type Indicator (MBTI). His work highlights that personality is complex and involves different mental processes rather than fixed traits.
  • The "Big Five" personality traits are a widely accepted framework in psychology for describing human personality. They include openness to experience (creativity and curiosity), conscientiousness (organization and dependability), extraversion (sociability and assertiveness), agreeableness (compassion and cooperativeness), and neuroticism (emotional instability and anxiety). These traits are measured on a continuum, meaning individuals can score high or low on each trait rather than fitting into fixed categories. This model helps capture broad patterns of behavior and thought but does not encompass all aspects of personality.
  • The Myers-Briggs Type Indicator (MBTI) categorizes people into 16 distinct personality types based on four dichotomies, such as Introversion vs. Extraversion. It is a typological model, meaning it sorts individuals into fixed categories rather than measuring traits on a continuum. The Big Five, in contrast, assesses personality traits on continuous scales, allowing for more nuanced and flexible descriptions. MBTI is often criticized for lacking strong scientific validity, while the Big Five is widely supported by empirical research.
  • Psychometric tests are standardized tools designed to measure psychological traits like personality, intelligence, or abilities. They function by presenting a series of questions or tasks and scoring responses to assess specific characteristics. These tests aim to produce objective, quantifiable data that can be compared across individuals. Their reliability depends on consistent results over time and validity in measuring what they claim to assess.
  • A bell curve distribution, also called a normal distribution, is a common pattern where most test scores cluster around the average, with fewer scores appearing as you move further from the center. It looks like a symmetrical, bell-shaped graph when plotted. This pattern suggests that the test measures traits that vary naturally in the popul ...

Counterarguments

  • The Rorschach test and other projective tests are designed to provide a qualitative depth of understanding rather than a quantitative assessment, and when used by trained professionals, they can offer valuable insights into a person's thought processes and emotional functioning.
  • Categorizing personality into types has practical utility in various settings, such as career counseling and team building, where a simplified understanding of personality can facilitate better communication and collaboration.
  • The "Big Five" personality traits, while scientifically backed, are not without their critics who argue that they may oversimplify the complexity of human personality or miss cultural nuances.
  • Psychometric tests are continually refined and validated through empirical research, and while they may not capture every nuance of personality, they can provide a useful framework for understanding and measuring personality constructs.
  • The use of bell curve distributions in psychometric testing is a standard practice in psychological assessment, reflecting the natural variation in human traits across populations.
  • The MMPI and other objective tests have been revised and updated to improve their validity and reliability, and they are widely used in c ...

Get access to the context and additional materials

So you can understand the full picture and form your own opinion.
Get access for free
Selects: How Personality Tests Work

Personality Tests in Corporate and Legal Contexts

Personality tests are commonly used in corporate settings and even legal proceedings, but their reliability and ethical implications are often called into question.

Corporations Use Mbti Tests For Employment Decisions Despite Creators' Warnings

Serious Consequences of Unreliable Personality Test Results

Josh Clark and the hosts discuss the widespread use of the Myers-Briggs Type Indicator (MBTI) in corporate America. Despite the MBTI being commonly referred to as a test, its creators, CPP, assert it should not be used as such. A significant number of companies—89 of the Fortune 100 as of the 1990s—have relied on the MBTI for employment decisions, including hiring, firing, and promotions. Yet, CPP cautions against using the MBTI for such purposes.

Clark emphasizes that psychologists view the MBTI with skepticism when it comes to its practical application in professional settings, indicating that the test is not typically used by serious psychologists.

Experts Slam Subjective Personality Assessments Impacting Lives

The MBTI’s use extends beyond corporate e ...

Here’s what you’ll find in our full summary

Registered users get access to the Full Podcast Summary and Additional Materials. It’s easy and free!
Start your free trial today

Personality Tests in Corporate and Legal Contexts

Additional Materials

Clarifications

  • The Myers-Briggs Type Indicator (MBTI) measures personality preferences based on four dichotomies: Introversion vs. Extraversion, Sensing vs. Intuition, Thinking vs. Feeling, and Judging vs. Perceiving. It categorizes individuals into 16 personality types by combining these preferences. The test is based on Carl Jung’s theory of psychological types, aiming to describe how people perceive the world and make decisions. However, it does not measure skills, abilities, or mental health.
  • CPP, now known as The Myers-Briggs Company, is the organization that owns and publishes the MBTI. They license the test and provide training and materials for its use. The MBTI was originally developed by Katharine Cook Briggs and her daughter Isabel Briggs Myers, not CPP itself. CPP's role is primarily in distributing and managing the test rather than creating it.
  • Psychologists are skeptical of the MBTI because it lacks strong scientific evidence supporting its reliability and validity. Reliability means the test should produce consistent results over time, which MBTI often does not. Validity means the test should accurately measure what it claims, but MBTI categories are seen as oversimplified and not predictive of behavior. Additionally, MBTI uses a binary system that ignores personality traits existing on a spectrum.
  • The MMPI (Minnesota Multiphasic Personality Inventory) is a clinical psychological test designed to assess mental health and diagnose disorders. Unlike the MBTI, which categorizes personality into types, the MMPI measures a range of psychological conditions using standardized scales. The MMPI is widely regarded as scientifically valid and is used in clinical and forensic settings. The MBTI focuses on personality preferences and is less supported by empirical research.
  • Personality tests in legal proceedings are often used to assess a person's mental state, credibility, or risk of reoffending. They can influence decisions in custody battles, competency hearings, and sentencing. Courts may consider these assessments alongside other evidence to inform judgments. However, their scientific validity and objectivity are frequently challenged.
  • Using personality tests in employment can lead to discrimination if tests are biased or misused, violating equal opportunity laws. Legally, relying on unvalidated tests risks wrongful hiring or firing, resulting in lawsuits for unfair labor practices. Ethically, these tests may invade privacy and reduce individuals to simpl ...

Counterarguments

  • The MBTI and similar personality tests can provide a structured framework for understanding and discussing personality differences within teams, which can be beneficial for team building and communication.
  • Some proponents argue that when used correctly, personality tests can offer a starting point for personal development and self-awareness, which can be valuable in a professional context.
  • While the MBTI may not be supported by all psychologists, there are professionals who use it as one of many tools to help clients understand themselves better, suggesting it can have practical applications when not overemphasized or misused.
  • The use of personality assessments in legal proceedings might be supported by the argument that they can provide additional information about an individual's tendencies or behaviors, which could be relevant in certain cases.
  • It's possible that the lawsuits mentioned are not solely due to the use of personality tests but could also involve other factors related t ...

Get access to the context and additional materials

So you can understand the full picture and form your own opinion.
Get access for free

Create Summaries for anything on the web

Download the Shortform Chrome extension for your browser

Shortform Extension CTA