The HED Task Catalog is under development. IDs are not stable until formal release. Comments are welcome at github.com/hed-standard/hed-task/issues.

Trust Game Task

HED task ID: hedtsk_trust_game

Family: Social cognition and social choice tasks

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

An experiment is an instance of this task when its procedure matches, it manipulates at least one of the listed variables, and it records at least one of the listed measures.

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

Named versions that change what the participant experiences or does. The identifier of a variation is hedvar_<task>__<variation>.

Variation

Description

Justification

Standard Two-Stage Trust Game

hedvar_trust_game__standard_two_stage_trust_game

Investor sends, tripled, trustee returns portion.

Canonical Berg et al.: investor sends, trustee returns

One-Shot vs. Repeated

hedvar_trust_game__one_shot_vs_repeated

Single interaction vs. multiple rounds with same partner.

Single vs. multiple rounds; repeated play enables reputation building

Multiplier Variation

hedvar_trust_game__multiplier_variation

2×, 3×, 4× multiplication factors.

Different multiplication factors; changes investment incentive

Trust Game with Reputation

hedvar_trust_game__trust_game_with_reputation

Providing partner’s history of returns.

Trustee reputation history visible; changes available social information

Partner Selection Trust Game

hedvar_trust_game__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

hedvar_trust_game__anonymous_vs_face_to_face

Varying social presence.

Social identification manipulation changes accountability

Social Identity Manipulation

hedvar_trust_game__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 is designed to engage the following processes:

Key references

  • Berg, J., Dickhaut, J., & McCabe, K. (1995). Trust, reciprocity, and social history. Games and Economic Behavior, 10(1), 122-142. (DOI)

  • 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. (DOI, PubMed)

  • 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. (DOI, PubMed)

Further references

  • Johnson, N. D., & Mislin, A. A. (2011). Trust games: A meta-analysis. Journal of Economic Psychology, 32(5), 865–889. (DOI)

  • 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. (DOI)

  • 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. (DOI, PubMed)

  • 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. (DOI, PubMed)