Thinking Fast and Slow — Daniel Kahneman
Core Thesis
The mind operates in two systems: System 1 (fast, intuitive, emotional) and System 2 (slow, deliberate, logical). Most of our errors come from System 1 making judgments that feel right but are systematically wrong.
Key Principlesflashcards
What are System 1 and System 2, and when does each dominate? ? System 1: Fast, automatic, effortless, emotional. Always running. Handles 95% of daily decisions. Relies on heuristics and patterns. System 2: Slow, deliberate, effortful, logical. Lazy — only activates when forced. Handles complex calculations and careful reasoning. System 1 dominates when you’re: tired, rushed, multitasking, or overloaded. System 2 activates when: the stakes are obvious, you’re specifically focusing, or System 1 produces a surprise.
What is the “anchoring effect” and how does it influence decisions? ? The first number you encounter disproportionately influences your judgment, even if it’s arbitrary. Examples:
- Asking “Is the population of Turkey more or less than 5 million?” vs “35 million?” changes people’s subsequent estimates dramatically
- In salary negotiation, whoever says a number first sets the anchor Defense: be aware of anchors. Set your OWN anchor first. Ask “what would we think if this number were completely different?”
What is “loss aversion” and how powerful is it? ? Losses feel roughly 2x as painful as equivalent gains feel good. Losing 100 feels nice. This means:
- People take irrational risks to avoid losses
- People hold onto losing investments too long (to avoid realizing the loss)
- Framing matters enormously: “90% survival rate” vs “10% mortality rate” changes decisions As a leader: frame changes as what people GAIN, not what they lose.
What is WYSIATI (“What You See Is All There Is”)? ? System 1 builds the best story it can from available information — and never asks “what am I NOT seeing?” It jumps to conclusions based on limited data and feels confident doing it. This is why:
- First impressions are so powerful (and often wrong)
- We’re overconfident in decisions based on small samples
- We don’t naturally ask “what’s missing from this picture?” Antidote: always ask “What would change my mind? What information am I missing?”
What is “substitution” and how does it cause bad decisions? ? When faced with a hard question (System 2), System 1 secretly substitutes an easier question:
- Hard: “How happy are you with your life?” → Easy substitute: “What is my mood RIGHT NOW?”
- Hard: “Should we invest in this market?” → Easy: “Do I like the person pitching this?”
- Hard: “Is this candidate qualified?” → Easy: “Does this candidate remind me of me?” Recognizing substitution is one of the most powerful meta-cognitive skills.
What is the “planning fallacy” and how do you combat it? ? People consistently underestimate time, cost, and risk of future actions while overestimating benefits. Even KNOWING about the bias doesn’t fix it. Combat it with the “outside view”:
- Don’t ask “How long will MY project take?” (inside view)
- Ask “How long do projects LIKE this typically take?” (outside view / base rate)
- Use reference class forecasting: find 10 similar past projects and use their average.
What is the “halo effect”? ? When one positive trait (attractiveness, confidence, early success) colors your judgment of everything else about a person or idea. If someone is likable, we assume they’re also competent, honest, and smart. Works in reverse too (horn effect). Defense: evaluate traits independently. Force yourself to assess dimensions separately, in writing.
Situations
- decision-making, hiring, strategy, estimation, planning, risk-assessment, stakeholder-communication, self-awareness, avoiding-bias