Moral Decision-Making Under Ego Depletion in Virtual Reality: The Buffering Role of Emotion.

While dual-process theory has advanced our understanding of moral decision-making, traditional research has relied heavily on text-based scenarios. These paradigms fail to elicit genuine behavioural responses, thereby obscuring the underlying mechanisms of moral action. The present study employed two experiments to investigate the interactive effects of ego depletion and emotion on moral decision-making, as well as the underlying physiological mechanisms, within a Virtual Reality (VR) environment. Study 1 revealed that, compared to text-based conditions, VR elicited heightened physiological arousal-manifested as accelerated heart rate and respiratory rate-reflecting a state of high somatic engagement. Under low ego depletion, this immersion resulted in increased utilitarian tendencies. However, this facilitating effect of VR was nullified under high ego depletion conditions. Study 2 demonstrated that positive emotion effectively buffers the negative impact of ego depletion on moral decision-making, preserving utilitarian tendencies even under high depletion. These results suggest that moral decision-making in realistic contexts is not a purely cognitive exercise in abstract reasoning; rather, it is a resource-dependent process characterised by a dynamic interplay between cognition, emotion, and situational context. Beyond validating positive emotion as a buffer against cognitive depletion, this study underscores the critical importance of ecological validity.