Large language models are increasingly used for both task-based assistance and social companionship, yet research has typically focused on one or the other. Drawing on a survey (N = 202) and 30 interviews with high-engagement ChatGPT and Replika users, we characterize digital companionship as an emerging form of human-AI relationship. With both systems, users were drawn to humanlike qualities, such as emotional resonance and personalized responses, and non-humanlike qualities, such as constant availability and inexhaustible tolerance. This led to fluid chatbot uses, such as Replika as a writing assistant and ChatGPT as an emotional confidant, despite their distinct branding. However, we observed challenging tensions in digital companionship dynamics: participants grappled with bounded personhood, forming deep attachments while denying chatbots "real" human qualities, and struggled to reconcile chatbot relationships with social norms. These dynamics raise questions for the design of digital companions and the rise of hybrid, general-purpose AI systems.

翻译：大型语言模型正日益被同时用于任务型协助和社交陪伴，然而现有研究通常仅聚焦其中一种用途。基于对202名高活跃度ChatGPT和Replika用户的问卷调查及其中30人的深度访谈，我们将数字陪伴界定为一种新兴的人机关系形态。研究发现，用户既被两类系统的人类特质（如情感共鸣与个性化回应）所吸引，也青睐其非人类特质（如持续可用性与无限包容性）。这导致了聊天机器人使用场景的流动性：尽管品牌定位迥异，Replika常被用作写作助手，而ChatGPT则成为情感倾诉对象。然而，我们在数字陪伴的动态关系中观察到具有挑战性的张力：参与者既陷入有限人格的困境——在形成深度依恋的同时否认聊天机器人的"真实"人类属性，又难以协调聊天机器人与社会规范的关系。这些动态机制对数字伴侣的设计及混合型通用AI系统的兴起提出了新的思考。