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 individualized 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 analyze how SRs may foster companionship, reduce social anxiety, and improve interpersonal skills, 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. To navigate these challenges, we outline a research agenda promoting interdisciplinary theory development longitudinal studies, drawing on representative samples to address the ethical concerns of SRs. We argue that SRs hold promise as a social intervention when ensuring they complement rather than replace human relationships. By integrating interdisciplinary insights, this paper provides a foundation for understanding and guiding the responsible design of SRs for addressing loneliness.