Avatar Anthropomorphism and Avatar Realism in Older Adult–AI Chatbot Interaction: Effects on Trust, Perceived Warmth, and Perceived Competence

As the global population ages, loneliness among older adults has emerged as a public health concern. Artificial intelligence (AI) chatbots have shown promise in addressing loneliness. This study investigated how avatar anthropomorphism and avatar realism influence trust, perceived warmth, and competence in older adult–AI chatbot interaction. A 2 (avatar anthropomorphism: high vs. low) × 2 (avatar realism: realistic vs. cartoon) between-subjects experiment was conducted with 80 older adults. Results showed that avatar realism significantly increased trust and perceived competence, with a marginal effect on warmth. Avatar anthropomorphism had no significant effect. Mediation analysis revealed that perceived warmth and competence mediated the relationship between avatar realism and trust. These findings underscore the importance of avatar realism, perceived warmth, and competence in fostering trust. The study contributes to (1) advancing the literature on older adult–AI chatbot interaction and (2) providing actionable guidelines for developing trustworthy AI chatbots for older adults.