Executive Function and Social Behaviour: Causal Evidence from Loading Working Memory and Inhibitory Control

This paper investigates how domain-specific executive functions contribute to perspective-taking and prosocial behaviour. Across two pre-registered experiments, we independently manipulated working memory (WM) and inhibitory control (IC) to assess their effects on social cognition. In Experiment 1 (N = 128), working memory load was varied using a dual-task paradigm, and participants completed behavioural and eye-tracking measures of perspective-taking and prosociality. WM load impaired perspective-taking, and this effect was larger under non-social than social load. Conversely, individual differences in prosocial behaviour were associated with higher social (but not non-social) WM capacity and larger support cliques, suggesting that dissociable cognitive mechanisms underpin different social outcomes. Notably, WM performance did not vary across social versus non-social conditions, indicating that increased social complexity did not impair WM, and that the relationship is not bidirectional. In Experiment 2 (N = 122), IC was manipulated using an ego-depletion task, but no significant effects of load emerged. We discuss the challenges of isolating IC from WM and highlight the need for improved methods in future research. Overall, these findings provide causal evidence linking WM to social skills, underscore the importance of distinguishing between social and non-social domains of executive functioning, and point to key conceptual and methodological priorities for the field.