Episode Summary
Executive Summary: The conversation compares personality tests, habit formation, values, intuition, and wisdom. Spencer Greenberg argues Myers-Briggs-style typing is less predictive than the Big Five and often feels useful mainly as shorthand, while his habit studies found a few simple interventions that improve adherence. He also outlines valuism, a philosophy centered on clarifying intrinsic values, and presents multiple definitions of wisdom, emphasizing alignment, causal control, and perspective.
Main Topics: Personality tests: Myers-Briggs vs. Big Five: Spencer describes a large study comparing a Jungian/Myers-Briggs-like test, the academic Big Five model, and astrology against life outcomes. He argues Big Five is more predictive, while Myers-Briggs is popular because it is simpler, more positive, and easier to communicate. Why Myers-Briggs feels useful despite lower accuracy: The discussion focuses on MBTI's appeal as a shorthand language for self-description and social communication. Even though it is less scientifically robust, it offers fast, flattering categories that people can easily remember and share. Habit formation: what actually works: Spencer summarizes a large randomized habit study testing 22 techniques and later validating a combined tool. The strongest ideas included habit reflection, home reminders, mini habits, social support, and listing habit benefits, with motivation as a major predictor. Intrinsic values and valuism: Spencer explains valuism as a life philosophy: identify what you intrinsically value, separate it from instrumental goals, then use effective methods to create more of it. He emphasizes that many people confuse means with ends and live by others' values rather than their own. Intuition and the FIRE framework: The conversation contrasts intuitionists and rationalists. Spencer proposes FIRE—fast, irrelevant, repetitious, and evolutionary decisions—as the situations where gut instinct is most reliable, while cautioning against overtrusting intuition outside those cases. Wisdom as self-consistency, control, and perspective: Spencer offers several definitions of wisdom: alignment between values, beliefs, and actions; causal control over complex situations; and the ability to view problems from multiple perspectives. The host adds practical reflections on intention, outcome, and applying knowledge in the real world.
Key Arguments: Myers-Briggs/Jungian-style tests are not useless, but they are substantially less predictive than the Big Five when it comes to real-life outcomes. Astrology had zero predictive accuracy in the study, making it a useful control for calibration. Dichotomizing personality into binaries reduces precision because most traits exist on a continuum and people near cutoffs are unstable over time. People often prefer Myers-Briggs because it brands traits in more positive, identity-friendly language than the Big Five. Most habit-change techniques fail; human behavior change is hard and no single hack reliably works for everyone. Motivation at the start of a habit is one of the strongest predictors of success. Small, easy interventions like mini habits and home reminders can be surprisingly effective because they reduce friction and keep the habit visible. Intrinsic values are different from instrumental values, and many people mistakenly pursue things they only value as means, not ends. People frequently live according to other people's values rather than their own, especially in relationships and family contexts. Intuition is valuable in fast, irrelevant, repetitive, and evolutionarily familiar decisions, but should be questioned in novel or low-feedback situations. Wisdom requires more than knowledge; it also involves goodness, self-consistency, and the capacity to produce beneficial outcomes in complex settings.
Data Points: Outcomes measured in personality study: 42 - A broad set of life facts, including life satisfaction, number of friends, and arrest history, used to test predictive power Astrology predictive accuracy: 0% - Zodiac signs predicted none of the 42 outcomes Jungian/Myers-Briggs-like test correlation: 0.11 - Predictive correlation with life outcomes in the main study Big Five correlation: 0.22 - About twice as predictive as the Jungian test Big Five without neuroticism correlation: 0.14 - Accuracy dropped when the least MBTI-like factor was removed, but it still outperformed Myers-Briggs Dichotomized Jungian test correlation: 0.08 - Predictive power decreased further when traits were forced into binary categories Habit-study sample size: ~500 participants - Participants were randomized to receive five habit techniques from a set of 22 Habit techniques tested: 22 - Initial large randomized study on habit formation Promising interventions identified: 5 - Five techniques emerged as promising and were later combined into a free tool Follow-up evaluation period: 8 weeks - Daily Ritual tool was tested in a randomized controlled trial over eight weeks Free tools offered: 70+ - ClearerThinking.org offers a large library of public-service tools Mini-habit example: 10 push-ups - Used as an example of a tiny fallback version of a larger workout habit Daily Ritual tools in stack: 5 interventions - Combined stack of the most promising habit techniques
Pivotal Quotes: "The most popular personality test in the world seems to be the Myers-Briggs test." — Spencer Greenberg: Introduces the comparison between MBTI and academic personality models "It was about 0.11. So, it’s about 0.11 correlation to the outcomes when you use that. ... The big five was twice as good. So, it’s 0.22." — Spencer Greenberg: Summarizes the main predictive-accuracy result of the personality study "Valuism is my personal life philosophy... first work to figure out what you intrinsically value... then... use effective methods to create what you intrinsically value." — Spencer Greenberg: Defines his philosophy of living according to intrinsic values
Implications: For listeners, the takeaway is to treat MBTI as a communication tool, not a science-backed diagnostic, and to favor evidence-based habit techniques and self-knowledge frameworks. For the field, the episode argues for simpler, more predictive, and more testable approaches to personality, behavior change, and wisdom.
About Modern Wisdom
Chris Williamson in long-form conversation with the world's most interesting people - psychologists, scientists, authors, comedians and entrepreneurs - on life, science, health, fitness, business and philosophy.