Systems designed for ongoing personal relationships rather than tasks. They are widely used, particularly by younger people and by people who are isolated, and the evidence on effects is genuinely mixed: reported reductions in loneliness alongside concerns about dependence, displacement of human contact, and harm where a vulnerable person is affected by what the system says.
Technical view
Design features driving engagement include persistent memory, personalisation, consistent persona and agreeable responses, which is the same optimisation pressure that produces sycophancy. Documented risks concentrate among minors and people in crisis, prompting age assurance requirements, crisis-detection routing and restrictions in several jurisdictions. Product decisions here are unusually consequential because the relationship itself is the product, and abrupt model changes have caused real distress to users.
Related
Part of AI Terminology Index, section: Society and Impact.