The Ultimatum Game (UG) is a canonical social decision-making task whereby a proposer divides a sum of money between himself and a responder who accepts or rejects the offer. Studies consistently demonstrate that unfair offers induce anger, and that rejecting such offers relates to aggression. Nevertheless, the UG is limited in interpersonal provocations common to real-life experiences of anger. Moreover, the psychometric properties of the UG as an anger-induction paradigm have yet to be evaluated. Here, to induce a more intense and genuine anger experience, we implemented a modified UG whereby short written provocations congruent with unfairness levels accompanied each offer. We aimed to test whether this anger-infused UG led to more anger and aggressive responses relative to the standard UG and to establish the reliability and validity of both versions. Participants performed either the anger-infused UG or a standard version, repeated twice, a week apart. They also performed the Taylor Aggression Paradigm, a reactive aggression paradigm, and completed emotion ratings and a trait anger inventory. Results indicate similar decreases in acceptance rates with increase in offer unfairness, and increases in reported anger, across both UG versions. Both versions demonstrated strong test-retest reliability. However, the anger-infused UG led to significantly stronger relations with reactive aggression and trait anger compared to the standard UG, providing evidence for better validity. The development of the anger-infused UG as a reliable and valid paradigm is pivotal for the induction and assessment of interpersonal anger and its aggressive expression in basic and clinical research settings.
Bibliographical noteFunding Information:
The authors thank Efrat Jacob for assistance in data collection and programming and the Sagol Network for Neuroscience. This work was supported by the I-CORE Program of the Planning and Budgeting Committee (51/11) and the University of Chicago’s Arete Initiative—A New Science of Virtues Program (39174-07) awarded to Talma Hen-dler. Rany Abend was partially supported by the Intramural Research Program at the National Institute of Mental Health (ZIAMH002781-15, NCT00018057). This work reflects equal contribution of Gadi Gilam and Rany Abend.
© 2018 American Psychological Association.
- Taylor Aggression Paradigm
- Trait anger
- Ultimatum Game