Abstract
Previous research suggests that humans assign a higher intrinsic social reward value to cooperative actions, fostering a preference for cooperation even when it is more costly than acting alone. We recently found this preference reverses when partners use separate devices rather than working side-by-side on a shared interface. This raises the question of how social pressure—arising from physical proximity and/or the ability to monitor a partner’s decisions—influences cooperative behaviour. Here, we investigate whether social pressure created by monitoring a partner’s decision results in a preference for cooperation even when partners use separate devices. Twenty-five adult pairs, each composed of a “Decision-maker” and “Helper,” completed a computerized box-clearing task, with roles switching halfway through the experiment. In 50% of trials, Decision-makers were forced to complete the task alone or with the Helper. In the remaining trials, Decision-makers chose to act alone or cooperatively. During together trials, participants had to clear the same box within 200 ms of each other without communication or visual feedback of one another’s movements. To induce social pressure, participants saw whether the upcoming trial was forced or choice-based, allowing the Helper to know whether the Decision-maker included them. Contrary to our earlier work, we found a significant preference for costly joint action over individual action despite faster and more efficient box-clearing when performing alone. These findings suggest that decisions to cooperate may be driven more by social pressure than a greater intrinsic social reward value, highlighting the importance of the social context for cooperation.
