# Characterizing Ultimatum Game responders: a scoping review of factors that influence decision-making through an evolutionary lens

## TL;DR

This review explores how internal and external factors influence decision-making in the Ultimatum Game, offering insights into human behavior through an evolutionary and psychological lens.

## Contribution

The paper provides a comprehensive framework of factors influencing responder behavior in the Ultimatum Game, integrating evolutionary and cognitive theories.

## Key findings

- Internal factors like emotions and personality significantly affect responder decisions in the Ultimatum Game.
- External factors such as social norms and power dynamics shape bargaining behavior in the game.
- Kahneman’s dual system theory helps explain the interplay between fairness, reciprocity, and self-interest in decision-making.

## Abstract

The Ultimatum Game is a widely used tool for studying conflict resolution within a bargaining framework. This scoping review aims to comprehensively examine the various internal and external factors influencing the responder’s behavior in this game and compile the status quo of the knowledge space. 31 pertinent research articles were identified from databases like Google Scholar, PubMed and JStor, using the following keywords “ultimatum game,” “responder behavior,” “emotions and the ultimatum game,” “fairness in the ultimatum game,” “social norms and the ultimatum game,” “punishment game,” “impunity game,” “outside options in the ultimatum game.” An analysis of the same yielded two broad domains of influencing factors: internal and external. Internal factors encompassed emotions, personality traits, and cognitive capabilities, showcasing their significant influence on decision-making. External factors, including ownership, social norms, power dynamics, outside options, gender, and attraction, revealed how the context of the game shaped responder choices. This review investigates how internal and external factors influence bargaining behavior within the Ultimatum Game, distinguishing between typical and atypical responder behavior. Invoking Kahneman’s dual system theory offer insights into the evolutionary roots and modern cognitive processes guiding decision-making. The interplay between these systems reveals nuanced responses to fairness, reciprocity, and self-interest, challenging traditional economic models. While acknowledging the oversimplification of brain dynamics in these studies and also the need for cultural integration, the current review compiles a framework that advances our understanding of human behavior across disciplines, particularly for economics, psychology, and evolutionary biology. Refining this model promises deeper insights into decision-making processes amidst societal complexities.