While Human-Centric Foundation Models (HFM) excel at perceiving and generating human data, they remain passive, struggling with real-time interaction and adaptation. This limits real-world deployment. The emerging field of Interactive HFM (I-HFM) addresses this by enabling bidirectional engagement. I-HFMs operate across three critical dimensions: (a) interacting with users for intuitive content creation/refinement, (b) interacting with environments to learn and adapt like humans, and (c) interacting with other agents for collaborative task-solving. This interactivity transforms AI from passive models into proactive, human-like agents, bridging the gap towards responsive, socially intelligent AGI that integrates seamlessly into human societies.