# Amos Tversky ![[50 Resources/51 Attachments/51.03 Public/2026-02-09 Amos Tversky.jpg|400]] Amos Tversky (1937–1996) was an Israeli-American cognitive and mathematical psychologist whose collaboration with [[Daniel Kahneman]] transformed our understanding of [[Decision Making]] and founded [[Behavioral Economics]]. Together they developed prospect theory, identified systematic cognitive biases, and demonstrated that humans deviate from rational choice in predictable ways. Their work earned Kahneman the Nobel Prize in Economics in 2002; Tversky had died six years earlier and Nobel Prizes are not awarded posthumously. Born in Haifa, Tversky served as a paratrooper in the Israeli Defense Forces before studying psychology. He was known for his mathematical rigor, incisive wit, and collaborative brilliance. His work with Kahneman produced foundational papers on heuristics (availability, representativeness, anchoring), framing effects, and loss aversion. Their partnership is chronicled in Michael Lewis's book *The Undoing Project*. Tversky's influence extends across psychology, economics, medicine, law, and public policy. ## Key Contributions (with Kahneman) | Contribution | Description | |--------------|-------------| | **Prospect Theory** | People evaluate outcomes relative to a reference point | | **Loss aversion** | Losses hurt more than equivalent gains feel good | | **Availability heuristic** | Judge probability by ease of recall | | **Representativeness** | Judge likelihood by similarity to stereotype | | **Anchoring** | Initial values unduly influence estimates | | **Framing effects** | How options are presented affects choice | ## Prospect Theory ``` Classical Expected Utility: Prospect Theory: ┌─────────────────────────┐ ┌─────────────────────────┐ │ Value = Utility × Prob │ │ Value is relative to │ │ │ │ reference point │ │ Linear in probability │ │ │ │ │ │ Loss aversion: losses │ │ Gains = Losses │ │ weighted ~2× gains │ │ (same absolute value) │ │ │ └─────────────────────────┘ │ Certainty effect: │ │ overweight small probs │ └─────────────────────────┘ ``` ## Career Timeline | Year | Event | |------|-------| | 1937 | Born in Haifa, British Palestine | | 1961 | BA from Hebrew University | | 1965 | PhD from University of Michigan | | 1969 | Met Kahneman at Hebrew University | | 1971 | "Belief in the Law of Small Numbers" | | 1974 | "Judgment Under Uncertainty" (Science) | | 1979 | "Prospect Theory" (Econometrica) | | 1978 | Moved to Stanford University | | 1981 | "The Framing of Decisions" | | 1996 | Died of metastatic melanoma | | 2002 | Kahneman awarded Nobel (Tversky credited) | ## Heuristics and Biases | Heuristic/Bias | Description | Example | |----------------|-------------|---------| | **Availability** | Ease of recall = high probability | Shark attacks seem common after news | | **Representativeness** | Similarity to stereotype | "Linda problem" conjunction fallacy | | **Anchoring** | Initial value influences estimate | Negotiation starting prices | | **Conjunction fallacy** | P(A∩B) judged > P(A) | Bank teller vs feminist bank teller | | **Base rate neglect** | Ignore prior probabilities | Overestimate rare diseases | ## Impact | Domain | Influence | |--------|-----------| | **Economics** | Behavioral economics, Nobel Prize | | **Finance** | Behavioral finance, investor psychology | | **Medicine** | Medical decision-making, risk communication | | **Law** | Jury decision-making, settlement decisions | | **Public policy** | Nudge theory, choice architecture | | **AI** | Modeling human-like reasoning | ## Major Works | Work | Year | Contribution | |------|------|--------------| | "Belief in the Law of Small Numbers" | 1971 | Small sample bias | | "Judgment Under Uncertainty" | 1974 | Heuristics catalog | | "Prospect Theory" | 1979 | Alternative to expected utility | | "The Framing of Decisions" | 1981 | Presentation effects | | "Advances in Prospect Theory" | 1992 | Cumulative prospect theory | ## Quotes <!-- QueryToSerialize: LIST FROM #type/quote AND [[Amos Tversky]] WHERE public_note = true SORT file.name ASC --> ## Books <!-- QueryToSerialize: LIST FROM #type/book AND [[Amos Tversky]] WHERE public_note = true SORT file.name ASC --> ## References - https://en.wikipedia.org/wiki/Amos_Tversky - Lewis, M. (2016). *The Undoing Project* ## Related - [[Daniel Kahneman]] - [[Decision Making]] - [[Behavioral Economics]] - [[Cognitive biases]] - [[Behavioral Economics]] - [[Heuristics]] - [[Prospect Theory]] - [[Cognitive Psychology]] - [[Bounded Rationality]]