Trust Game Task¶
HED Task ID: hedtsk_trust_game
Also known as: Trust Game, TG, Investment Game
Two-stage exchange in which an investor transfers a fraction of an endowment (multiplied on receipt), and a trustee returns some fraction; amounts transferred index trust and reciprocity.
Description¶
A sequential two-player game in which the investor decides how much of an endowment to send to the trustee; the sent amount is multiplied (typically 3x), and the trustee decides how much to return. The investor faces a dilemma: trusting yields potentially higher mutual payoffs but risks exploitation. fMRI reveals that trust decisions engage theory-of-mind regions (medial PFC, temporoparietal junction) and reward regions (ventral striatum) that track mutual cooperation and reciprocity.
Inclusion test¶
Procedure |
An investor receives an endowment and chooses how much to send to a trustee; the amount is multiplied (typically tripled). The trustee decides how much to return to the investor. |
Manipulation |
Multiplication factor; endowment size; partner identity; reputation information; one-shot vs. repeated. |
Measurement |
Amount invested (trust); amount returned (trustworthiness); investment and return ratios. |
Variations¶
Variation |
Description |
Justification |
|---|---|---|
Standard Two-Stage Trust Game |
Investor sends, tripled, trustee returns portion. |
Canonical Berg et al.: investor sends, trustee returns |
One-Shot vs. Repeated |
Single interaction vs. multiple rounds with same partner. |
Single vs. multiple rounds; repeated play enables reputation building |
Multiplier Variation |
2×, 3×, 4× multiplication factors. |
Different multiplication factors; changes investment incentive |
Trust Game with Reputation |
Providing partner’s history of returns. |
Trustee reputation history visible; changes available social information |
Partner Selection Trust Game |
Choose which of several potential partners to trust. |
Participant selects partner before trust game; adds partner choice |
Anonymous vs. Face-to-Face |
Varying social presence. |
Social identification manipulation changes accountability |
Social Identity Manipulation |
In-group vs. out-group partners. |
In-group vs. out-group trustee; tests trust as function of group membership |
Cognitive processes¶
This task engages the following cognitive processes:
Key references¶
{‘authors’: ‘Berg, J., Dickhaut, J., & McCabe, K.’, ‘year’: 1995, ‘title’: ‘Trust, Reciprocity, and Social History’, ‘venue’: ‘Games and Economic Behavior’, ‘venue_type’: ‘journal’, ‘journal’: ‘Games and Economic Behavior’, ‘volume’: ‘10’, ‘issue’: ‘1’, ‘pages’: ‘122-142’, ‘doi’: ‘10.1006/game.1995.1027’, ‘openalex_id’: None, ‘pmid’: None, ‘citation_string’: ‘Berg, J., Dickhaut, J., & McCabe, K. (1995). Trust, reciprocity, and social history. Games and Economic Behavior, 10(1), 122-142.’, ‘url’: ‘https://doi.org/10.1006/game.1995.1027’, ‘source’: ‘crossref’, ‘confidence’: ‘high’, ‘verified_on’: ‘2026-04-20’}
{‘authors’: ‘King-Casas, B., Tomlin, D., Anen, C., Camerer, C. F., Quartz, S. R., & Montague, P. R.’, ‘year’: 2005, ‘title’: ‘Getting to Know You: Reputation and Trust in a Two-Person Economic Exchange’, ‘venue’: ‘Science’, ‘venue_type’: ‘journal’, ‘journal’: ‘Science’, ‘volume’: ‘308’, ‘issue’: ‘5718’, ‘pages’: ‘78-83’, ‘doi’: ‘10.1126/science.1108062’, ‘openalex_id’: None, ‘pmid’: None, ‘citation_string’: ‘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.’, ‘url’: ‘https://doi.org/10.1126/science.1108062’, ‘source’: ‘crossref’, ‘confidence’: ‘high’, ‘verified_on’: ‘2026-04-20’}
{‘authors’: ‘Rilling, J. K., Gutman, D. A., Zeh, T. R., Pagnoni, G., Berns, G. S., & Kilts, C. D.’, ‘year’: 2002, ‘title’: ‘A Neural Basis for Social Cooperation’, ‘venue’: ‘Neuron’, ‘venue_type’: ‘journal’, ‘journal’: ‘Neuron’, ‘volume’: ‘35’, ‘issue’: ‘2’, ‘pages’: ‘395-405’, ‘doi’: ‘10.1016/s0896-6273(02)00755-9’, ‘openalex_id’: None, ‘pmid’: None, ‘citation_string’: ‘Rilling, J. K., Gutman, D. A., Zeh, T. R., Pagnoni, G., Berns, G. S., & Kilts, C. D. (2002). A neural basis for social cooperation. Neuron, 35(2), 395-405.’, ‘url’: ‘https://doi.org/10.1016/s0896-6273(02)00755-9’, ‘source’: ‘crossref’, ‘confidence’: ‘high’, ‘verified_on’: ‘2026-04-20’}
Recent references¶
{‘authors’: ‘Johnson, N. D., & Mislin, A. A.’, ‘year’: 2011, ‘title’: ‘Trust games: A meta-analysis’, ‘venue’: ‘Journal of Economic Psychology’, ‘venue_type’: ‘journal’, ‘journal’: ‘Journal of Economic Psychology’, ‘volume’: ‘32’, ‘issue’: ‘5’, ‘pages’: ‘865-889’, ‘doi’: ‘10.1016/j.joep.2011.05.007’, ‘openalex_id’: None, ‘pmid’: None, ‘citation_string’: ‘Johnson, N. D., & Mislin, A. A. (2011). Trust games: A meta-analysis. Journal of Economic Psychology, 32(5), 865–889.’, ‘url’: ‘https://doi.org/10.1016/j.joep.2011.05.007’, ‘source’: ‘crossref’, ‘confidence’: ‘high’, ‘verified_on’: ‘2026-04-20’}
{‘authors’: ‘Luo, Y., Eickhoff, S. B., Hétu, S., & Feng, C.’, ‘year’: 2017, ‘title’: ‘Social comparison in the brain: A coordinate‐based meta‐analysis of functional brain imaging studies on the downward and upward comparisons’, ‘venue’: ‘Human Brain Mapping’, ‘venue_type’: ‘journal’, ‘journal’: ‘Human Brain Mapping’, ‘volume’: ‘39’, ‘issue’: ‘1’, ‘pages’: ‘440-458’, ‘doi’: ‘10.1002/hbm.23854’, ‘openalex_id’: None, ‘pmid’: None, ‘citation_string’: ‘Bellucci, G., Chernyak, S. V., Goodyear, K., Eickhoff, S. B., & Krueger, F. (2017). Neural signatures of trust in reciprocity: A coordinate-based meta-analysis. Human Brain Mapping, 38(3), 1233–1248.’, ‘url’: ‘https://doi.org/10.1002/hbm.23854’, ‘source’: ‘crossref’, ‘confidence’: ‘high’, ‘verified_on’: ‘2026-04-20’}
{‘authors’: ‘Krueger, F., & Meyer-Lindenberg, A.’, ‘year’: 2019, ‘title’: ‘Toward a Model of Interpersonal Trust Drawn from Neuroscience, Psychology, and Economics’, ‘venue’: ‘Trends in Neurosciences’, ‘venue_type’: ‘journal’, ‘journal’: ‘Trends in Neurosciences’, ‘volume’: ‘42’, ‘issue’: ‘2’, ‘pages’: ‘92-101’, ‘doi’: ‘10.1016/j.tins.2018.10.004’, ‘openalex_id’: None, ‘pmid’: None, ‘citation_string’: ‘Krueger, F., & Meyer-Lindenberg, A. (2019). Toward a model of interpersonal trust drawn from neuroscience, psychology, and economics. Trends in Neurosciences, 42(2), 92–101.’, ‘url’: ‘https://doi.org/10.1016/j.tins.2018.10.004’, ‘source’: ‘crossref’, ‘confidence’: ‘high’, ‘verified_on’: ‘2026-04-20’}
{‘authors’: ‘Chang, L. J., Doll, B. B., van ’t Wout, M., Frank, M. J., & Sanfey, A. G.’, ‘year’: 2010, ‘title’: ‘Seeing is believing: Trustworthiness as a dynamic belief’, ‘venue’: ‘Cognitive Psychology’, ‘venue_type’: ‘journal’, ‘journal’: ‘Cognitive Psychology’, ‘volume’: ‘61’, ‘issue’: ‘2’, ‘pages’: ‘87-105’, ‘doi’: ‘10.1016/j.cogpsych.2010.03.001’, ‘openalex_id’: None, ‘pmid’: None, ‘citation_string’: “Chang, L. J., Doll, B. B., van’t Wout, M., Frank, M. J., & Sanfey, A. G. (2010). Seeing is believing: Trustworthiness as a dynamic belief. Cognitive Psychology, 61(2), 87–105.”, ‘url’: ‘https://doi.org/10.1016/j.cogpsych.2010.03.001’, ‘source’: ‘crossref’, ‘confidence’: ‘high’, ‘verified_on’: ‘2026-04-20’}