Preferences for costly cooperation are highly individualized

When deciding between action alternatives, we use information about the costs and rewards of each action to choose an appropriate plan. Curioni et al. (2022) recently found that participants had a strong preference for completing a virtual box-clearing task cooperatively with a partner rather than alone, despite it being more motorically and cognitively costly. Participants completed the task standing beside each other in close proximity, which may have created a social pressure to cooperate through a need to manage one’s reputation or a sense of commitment. Here, 50 human pairs—each composed of a “Decision-maker” and “Helper”—completed a box-clearing task modeled after Curioni et al. while seated farther away and out of view of one another. In 50% of trials, Decision-makers were forced to complete the task alone or with the Helper. In the remaining 50% of trials, Decision-makers chose to work alone or cooperatively. When working together, participants were required to synchronize their movements without communication or feedback of their partner’s movements. Decision-makers answered open-ended questions regarding why and when they chose to complete the task alone and together. We found a slight preference for individual action over costly joint action, yet this preference was not significantly different from chance. Inductive thematic analysis revealed two dominant themes: “chose actions with greater instrumental utility” and “chose actions with greater social value”. The identified themes suggest that preferences to cooperate are highly individualized, and that cooperative actions may provide additional social rewards that drive preferences for cooperation even when it is more costly.