What Makes a Virtual Celebrity Agent Trustworthy in VR? Exploring the Role of Stylization and Voice

Recent advances in generative AI have accelerated the deployment of virtual celebrity agents for commercial endorsements. However, little is known about how their visual style and vocal type, especially when these characteristics are generated via advanced AI reconstruction or voice cloning techniques, affect user trust, perceived realism, familiarity, and social presence. We extracted a representative clip of Sheldon Cooper from The Big Bang Theory as a baseline and generated multiple Sheldon virtual agents that varied in visual style (hand-sculpted, AI-reconstructed, or non-stylized) and vocal type (cloned or synthesized). A 3×2 within-subjects experiment (N = 30) revealed that visual style significantly affected user trust, perceived realism, familiarity, and social presence, while vocal type affected only perceived realism and familiarity. Comparisons between the virtual agents and the video baseline confirmed that even cutting-edge 3D modeling still differs significantly from authentic video representations. Behavioral data indicate that the relationship between interpersonal-distance variations and trust levels is not a simple linear one. These findings provide actionable guidance for designers leveraging generative AI to create trustworthy virtual avatars or agents and delineate new research avenues for virtual celebrity agents.