Empathy moderates the relationship between cognitive load and prosocial behaviour.

Cognitive load reduces both empathy and prosocial behaviour. However, studies demonstrating these effects have induced cognitive load in a temporally limited, artificial manner that fails to capture real-world cognitive load. Drawing from cognitive load theory, we investigated whether naturally occurring cognitive load from the ongoing COVID-19 pandemic moderated the relationship between empathy and prosocial behaviour (operationalised as support for public health measures). This large study in an Australian sample (N = 600) identified negative relationships between pandemic fatigue, empathy for people vulnerable to COVID-19, and prosocial behaviour, and a positive relationship between empathy and prosocial behaviour. Additionally, we found that the negative effect of the pandemic on prosocial behaviour depended on empathy for vulnerable others, with pandemic fatigue's effects lowest for those with the highest empathy. These findings highlight the interrelationships of cognitive load and empathy, and the potential value of eliciting empathy to ease the impact of real-world cognitive load on prosocial behaviour.