Relationships in the age of AI A review on the opportunities and risks of synthetic relationships to reduce loneliness

Loneliness is a pressing global health issue, yet traditional interventions often fall short due to scalability limitations and the individualised experiences of loneliness. The rise of generative artificial intelligence (AI) has enabled synthetic relationships (SRs)—ongoing associations with AI companions designed to simulate human-like social bonds. SRs offer, among other aspects, constant availability, adaptability, and emotional responsiveness, which potentially address loneliness. However, their growing integration into social life raises critical psychological, ethical, and societal questions. This paper examines the opportunities and risks of SRs through the lens of relationship science, psychology, and AI companionship research. We first highlight how existing loneliness interventions face the challenges of availability, scalability, and personalization. We then outline how SRs present a novel alternative to overcoming these challenges. Drawing mainly on social penetration, attachment, and interdependence theory, we analyse how SRs may foster companionship, reduce social anxiety, and support interpersonal skills development, potentially mitigating loneliness. However, we also identify significant risks, including emotional over-reliance, distorted social expectations, and privacy concerns. The widespread adoption of SRs may reshape human-human relationships, altering norms of intimacy and social connection. Looking ahead, we broaden the discussion to AI companionship beyond human-like forms, alternative modes of companionship, loneliness as social health, and the uniquely human aspects of relationship networks. We argue that adequately designed SRs hold promise as a social intervention when ensuring they complement, not replace, human relationships. By integrating interdisciplinary insights, this paper provides a foundation for understanding and guiding the responsible design of SRs for addressing loneliness.