Beauty Contest (Guess-the-Number)
Frequently Asked Questions
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Task overview
Pick a number between 0–100, aiming for two-thirds of the group average, used to estimate level‑k reasoning.
How to play
Enter your guess and submit; the system calculates the distance to the target and logs your performance.
Output metrics
Shows your guess, the group target, and the error; you can compare across rounds.
Data export
Supports CSV/JSON export for subsequent group analysis.
Show Details
About the Beauty Contest Game
Game Theory Foundation
The Beauty Contest game, famously used in experiments by Fehr and Tyran, tests the limits of strategic reasoning. The 'beauty' refers to guessing the most popular answer — the number closest to 2/3 of the average. Iterated elimination of dominated strategies leads to a unique Nash equilibrium at 0.
Level‑k Reasoning
Most people stop reasoning after one or two steps (Level‑1 or Level‑2 thinkers). A Level‑1 thinker guesses 33 (2/3 of 50, assuming others guess randomly). Level‑2 guesses 22 (2/3 of 33), and so on. The depth of strategic reasoning varies considerably across individuals.
Experimental Applications
This task is used in behavioral economics to study how cognitive limitations, educational background, and cultural factors influence strategic sophistication. It has revealed systematic departures from game-theoretic rationality.
References
- Nagel, R. (1995). Unraveling in guessing games: An experimental study. American Economic Review, 85(5), 1313-1326.
- Keynes, J. M. (1936). The general theory of employment, interest and money. Macmillan.
- Camerer, C. F., Ho, T.-H., & Chong, J.-K. (2004). A cognitive hierarchy theory of one-shot games. Quarterly Journal of Economics, 119(3), 861-898.
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About This Experiment
This experiment is an educational adaptation for demonstration purposes. It is not a clinical diagnostic tool. Results reflect your performance in this specific session and should not be interpreted as an assessment of your cognitive abilities.
Data Privacy
Your experiment data is processed and stored locally in your browser. No data is uploaded to any server unless you explicitly export it.
