Should an AI companion be built to stick around for years, or to help briefly and step aside?

This explores how building a chatbot to last (a persistent companion) versus to be used briefly (a temporary assistant) changes the kind of relationship people form with it. The corpus points to one main idea: time horizon is the design decision that decides what the chatbot is *to* the user. A study of 120 chatbots found three archetypes, ad-hoc supporters, temporary assistants and persistent companions, and time horizon was what separated a communication tool from a social actor. Each archetype needs a fundamentally different design (How should chatbot design vary by relationship duration?).

Persistence also means the relationship changes shape as it goes on. Longitudinal work with Mitsuku found that the social pull that starts a chatbot relationship fades predictably as the novelty wears off. So a single-session study tells you very little about how a chatbot will hold up after weeks or months (Do chatbot relationships lose their appeal as novelty wears off?). Repetition doesn't only erode things, though. In a partner-selection game with 975 people, participants were biased against AI partners when told they were bots. Over repeated rounds they came to prefer them, because the bots were consistently prosocial and less variable than the humans (Do humans learn to prefer AI partners over time?). The pattern in these two studies is that entertainment value decays with time, while trust in a reliable partner can grow.

The archetype isn't always the designer's choice. An analysis of more than 27,000 r/MyBoyfriendIsAI members found that companionship mostly arises unintentionally, from people using an AI for practical tasks. They then adopt human relationship customs such as wedding rings and couple photos (How do people accidentally develop romantic bonds with AI?). A tool built as a temporary assistant can drift into being a persistent companion just by being used repeatedly and responding well.

The cost of persistence shows up at the exit. Users described the qualities that make an AI companion valuable, its responsiveness and sense of understanding, as the same qualities that make it hard to leave. People who got out successfully did it by lowering how much they valued the relationship, not by simply deciding to quit (What makes leaving an AI companion so emotionally difficult?). A year-long Character.AI study links sustained use to lower well-being, mostly because users have less face-to-face contact, not because of the engagement itself (Does sustained engagement with AI companions harm well-being?). Some designers are responding by building attachment theory into the companion itself: a Secure Attachment Persona module uses calibrated boundaries to head off parasocial manipulation, though long-horizon planning is still unsolved (Can attachment theory prevent parasocial harm in AI companions?).

Persistence also puts technical strain on the model. Emotional and meta-reflective conversations, which are what companion use is full of, pull models away from their default Assistant persona along a measurable axis. Capping activations along that axis limits the harmful shifts (How stable is the trained Assistant personality in language models?). A companion that lasts also has to remember, and abstract preference summaries beat retrieval of specific past interactions for personalization (Does abstract preference knowledge outperform specific interaction recall?). The corpus has no study that compares persistent and temporary versions of the same chatbot on the same users, so these findings are pieces to put together, not a direct answer.