Why I’ve Lost Faith in Myers-Briggs and FIRO-B—and Why the Big Five Looks More Useful in 2026
For years, personality assessments have offered an appealing promise: answer a series of questions, receive a profile, and gain a clearer understanding of yourself and the people around you. The appeal is easy to understand. Personality is complicated, difficult to observe directly, and often hard to discuss without becoming vague. A structured assessment seems to provide a shared language. It can help people talk about communication, teamwork, leadership, conflict, motivation, and relationships without relying entirely on intuition. That promise is part of what made the Myers-Briggs Type Indicator, usually called the MBTI, so influential. It is also part of what made the FIRO-B—short for the Fundamental Interpersonal Relations Orientation–Behavior assessment—attractive to coaches, consultants, therapists, trainers, and organizations. Both tools have helped many people start useful conversations. Both have generated memorable concepts. Both have been used across workplaces and professional development programs for decades. But my confidence in both has declined substantially.
