Selects: How Personality Tests Work

Key Takeaways

Personality tests, particularly the Myers-Briggs Type Indicator, are widely used but often lack scientific validity.
The Myers-Briggs Type Indicator (MBTI) is criticized for forcing binary categories and relying on disavowed Jungian theories.
Personality typing evolved from ancient Greek humors to Carl Jung's work and efforts to quantify psychology.
More scientifically accepted models, like the 'Big Five,' measure personality traits on a spectrum, not discrete types.
Tests like the Rorschach and MMPI-2 face significant validity and reliability concerns, including potential misdiagnosis.
Many personality assessments are susceptible to self-reporting bias and the Forer effect, where vague descriptions seem accurate.

Host Josh Clark introduced a 2017 episode on personality tests, highlighting their scientific flaws and potential real-world consequences in diagnosis, hiring, or legal contexts.
The Myers-Briggs Type Indicator (MBTI) is widely used in corporate America, with 13% of companies and 89% of Fortune 100 companies utilizing it.
The MBTI has global reach and is translated into multiple languages, despite criticism of its scientific basis.

Personality categorization dates back to ancient Greek theories of four humors (black bile, yellow bile, phlegm, and blood).
Carl Jung's 1921 book 'Psychological Types' introduced concepts like sensation, intuition, thinking, feeling, and the introvert/extrovert dichotomy.
Jung's theories originated from his own thinking rather than extensive research, though he was a respected psychoanalyst.
Catherine Cook Briggs and Isabel Briggs-Myers later developed personality typing, inspired by Jung, in the post-World War II era to help women find suitable jobs.

Personality tests are categorized into projective (e.g., Rorschach) and objective types, with objective tests being standardized but final interpretations still allowing for subjectivity.
The Myers-Briggs Type Indicator (MBTI) gained widespread adoption after being picked up by CPP in 1975, particularly within corporate America.

The 'Big Five' personality traits—extroversion, agreeableness, conscientiousness, neuroticism, and openness to experience—are considered more scientifically accepted than the MBTI.
Psychologists view the Big Five as just one dimension of personality, emphasizing that a complete profile requires extensive study of motivations, emotions, and life stories.
The field of psychometrics uses sophisticated tests to place responses on a spectrum, typically showing a bell curve distribution.
Core psychometric principles include validity (accuracy of reflection) and reliability (consistency of results over time).

The MBTI sorts individuals into 16 personality types based on four dichotomies: introversion/extroversion, sensing/intuition, thinking/feeling, and judging/perceiving.
'Sensing' indicates a preference for empirical data, while 'intuition' relies on gut feelings; 'thinking' focuses on logic, 'feeling' on relationships and group harmony.
Taking the MBTI costs approximately $50, with an additional $100 for an hour of feedback and $16.95 for a career report.
Becoming certified to administer the MBTI requires a four-day training course costing $1,500-$1,600.

Despite warnings from its creators, the Myers-Briggs Type Indicator (MBTI) has been historically misused by companies for hiring and firing decisions.
The hosts suggest that poor HR practices, rather than the MBTI tool itself, are often to blame for such misapplications.
The MBTI's intended use is for team-building, encouraging employees to understand and celebrate their differences rather than for employment screening.

The MBTI is criticized for being scientifically baseless, as it relies on Carl Jung's theories largely disavowed by the broader psychology community.
It is also criticized for forcing individuals into binary categories when personality traits exist on a spectrum.
Further criticisms include its reliance on self-reporting, which introduces bias, and 'entangled' dichotomies where scales are correlated.
The creators, Isabel Myers and Katharine Briggs, developed personality types first and then created a test to fit them, rather than deriving types from data.

The Rorschach inkblot test is highly subjective, lacking scientific rigor, with interpretations varying significantly.
John Exner's 'Comprehensive System' in 1975 attempted to quantify answers to preserve its use, yet critics like Howard Garb state only about 10% meets basic scientific standards.
A 2000 study found that a significant percentage of mentally healthy elementary school children were labeled as borderline psychotic by the Rorschach test.
Despite these flaws, the test's results are used in legal contexts, including criminal trials and child custody cases.

The Minnesota Multiphasic Personality Inventory (MMPI-2), developed in the 1940s, uses a control group of mentally hospitalized individuals to establish a baseline for comparison, a method criticized for its potentially flawed definition of sanity.
Critics argue that personality tests use a faulty premise, failing to capture complex, hidden aspects of individuals.
Sociologist William White criticized the MMPI for perpetuating 'organization man' groupthink, which could lead to hiring discrimination based on deviations from a narrow definition of normalcy.
Personality inventories are compared to astrology due to their use of positive psychology and vague statements that appeal to a broad audience, a phenomenon linked to the Forer effect.