Trust Game
Classic investment game: each round you hold 10 tokens, send any amount to a trustee — it is tripled — and the trustee decides how much to return to you.
Frequently Asked Questions
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What does it measure?
Your trust behavior in this game — how many tokens you send to the other player. It is not a clinical measure of trait trust, and the partner is a simulated strategy, not a real person.
How is trust quantified here?
By the amount you send: larger transfers make you more vulnerable to the partner's return decision, even though keeping everything is the individually safer move. Average tokens sent over the 20 rounds is the main behavioral indicator.
Is the trustee a real person?
No. The trustee's return is generated by a seeded programmed strategy: a base return rate drawn each round from a triangular distribution (mode 30%, range 0–80%), nudged slightly upward when your investment rate is high — approximating the return distribution Berg, Dickhaut & McCabe (1995) observed. The strategy parameters and seed are included in the JSON export.
What does reciprocity look like?
In classic data, trustees typically return a partial share that scales with what they received; keeping everything is the exception rather than the rule in behavioral-economics samples. Here that pattern is built into the simulated strategy.
Does anonymity change behavior?
Yes — anonymity modestly lowers both trust and reciprocity, while communication and repeated interaction raise them.
Show Details
About the Trust Game
Experimental Economics
The Trust Game, developed by Berg, Dickhaut, and McCabe in 1995, is a foundational tool in behavioral economics. In this two-stage 'investment game' the investor sends part of an endowment to a trustee; the amount is tripled, and the trustee decides how much to return. In the original experiment investors sent about half of their endowment on average, and trustees returned roughly a third of the tripled amount — both far above what pure self-interest predicts.
Psychological Foundations
Sending tokens makes you vulnerable: the trustee could keep everything, so a larger transfer signals stronger trust. In repeated play, trustees tend to reciprocate — returns scale with the amounts they receive. This adaptation keeps the classic structure: you are always the investor, and the trustee is a programmed strategy whose base return rate is drawn each round from a triangular distribution (mode 30%, range 0–80%) and rises slightly when you invest more, approximating the reciprocity observed in the original study.
Applications
The Trust Game has been used to study trust across cultures, in patient populations with social deficits, and even between humans and AI. Cross-cultural studies reveal substantial variation in trustworthy behavior.
References
- Berg, J., Dickhaut, J., & McCabe, K. (1995). Trust, reciprocity, and social history. Games and Economic Behavior, 10(1), 122-142. 10.1006/game.1995.1027
- Johnson, N. D., & Mislin, A. A. (2011). Trust games: A meta-analysis. Journal of Economic Psychology, 32(5), 865-889. 10.1016/j.joep.2011.05.007
- King-Casas, B., Tomlin, D., Anen, C., Camerer, C. F., Quartz, S. R., & Montague, P. R. (2005). Getting to know you: Reputation and trust in a two-person economic exchange. Science, 308(5718), 78-83. 10.1126/science.1108062
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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.
