Dictator and Ultimatum Offers as Measures of Altruism

This study proposes and evaluates, in an incentivized laboratory experiment (N = 212), a theoretically motivated measure of altruism that integrates behavior from the dictator game and ultimatum game, drawing on economic and evolutionary perspectives. Participants completed a dual-role dictator and ultimatum, a modified die-under-the-cup task, and survey-based altruism measures. Using a preregistered design, the study assessed whether adding such theoretical structure improves prediction relative to the dictator offer and ultimatum rejection. Hypothesis tests provide mixed evidence: The proposed measure did not outperform either the dictator offer or ultimatum rejection, although it showed a marginally stronger association with self-reported altruism. A non-preregistered exploratory analysis examines the ultimatum–dictator offer gap as an exploratory behavioral quantity associated with survey-based altruism. Overall, the results highlight both the promise and the limits of adding theoretical structure to behavioral measures of altruism and help clarify directions for future research.