Facilitation or impairment: Social evaluation affects working memory through factors beyond task difficulty

Extensive research has shown that the presence of others, especially when perceived as evaluative, can either facilitate or impair performance on a variety of cognitive tasks, depending on their difficulty. While it is well-established that the mental abilities assessed in these studies are underpinned by common executive functions, such as working memory, there has been limited research dealing with the impact of social presence on these cognitive systems directly. The current study addressed this gap by examining the influence of evaluative social presence on working memory performance. In addition, motivational states were considered as potential drivers of the effects. Using a within-subjects design and pre-registered methods, 43 participants performed n-back tasks under varying cognitive load and social evaluation conditions, while motivational states were assessed through self-reported eustress and distress scales. The results revealed that under social evaluation, some individuals exhibit both improved accuracy and speed, while others demonstrate reduced accuracy (without a clear pattern in reaction times), regardless of cognitive load. The anticipated mediation of motivational states could therefore not be supported. These findings challenge traditional understandings of social presence effects, suggesting that its impact on working memory—and potentially other cognitive functions—may be influenced by factors beyond task difficulty. The results have important implications for the design of test environments and highlight the need for further research on moderating factors that could explain the large interindividual variability in social presence effects.