  Existing approaches to Theory of Mind (ToM) in Artificial Intelligence (AI)
overemphasize prompted, or cue-based, ToM, which may limit our collective
ability to develop Artificial Social Intelligence (ASI). Drawing from research
in computer science, cognitive science, and related disciplines, we contrast
prompted ToM with what we call spontaneous ToM -- reasoning about others'
mental states that is grounded in unintentional, possibly uncontrollable
cognitive functions. We argue for a principled approach to studying and
developing AI ToM and suggest that a robust, or general, ASI will respond to
prompts \textit{and} spontaneously engage in social reasoning.
