Trust Game, explained.
The Trust Game studies an exchange in which one person transfers resources that grow before another person decides how much to return.
Why it happens
The first transfer creates a larger potential joint payoff but exposes the sender to the receiver's choice. The sender cannot infer a guaranteed return from the multiplier alone. Expectations and reciprocity affect the interaction.
Investment games separate a trusting move from the recipient's opportunity to reciprocate.
Read the result
Compare the amount sent, the enlarged pot, and the amount returned. Increasing the multiplier creates more possible surplus; changing the return rule determines how that surplus is actually shared.
A worked example
A transfer creates a larger pot
A sender gives four units, which become twelve for the receiver under a threefold multiplier.
Returning four restores the transferred amount; returning six shares more of the resulting benefit with the sender.
The size of the total and the fairness or profitability of the exchange are separate questions.
OPTIONAL DEEPER DETAILGo deeper: inside the model
Inside this model
Sender begins with 10 and sends x; the transfer becomes 3x. Recipient returns r% of 3x. Final sender tokens are 10−x+3xr/100; recipient tokens are 3x(1−r/100). The chart fixes the return share while varying the amount sent.
Where this idea is useful
A practical use
A team member shares time or information first, hoping that the other person will reciprocate after the collaboration becomes more valuable.
A common misconception
“A larger multiplier guarantees a better deal for the sender.”
The sender's payoff also depends on what the receiver returns. More possible surplus is not a promise of reciprocity.
What this explanation leaves out
- You control both roles in this solo game. It demonstrates possible payoffs, not an empirical prediction of how strangers reciprocate.
Does this measure whether someone is trustworthy in real life?
A simplified game reveals behavior under its stated stakes and rules. It does not establish a person's character across settings with different relationships, information, and consequences.
Which part of the outcome is controlled by your partner after you commit?
Further reading
Explore the original research or the teaching reference behind this experiment.