I’m a baby coder – I don’t know nearly enough, so don’t take this as gospel but I do have a healthy bit of experience with the JSON at this point.
But no, I don’t think it’s doable in JSON. You’re talking about tracking player interactions with NPCs, proximity to NPCs, or at the very least a counter for how long it’s been since they last saw another human. These are things that, to my knowledge, would require code.
You can do other things with morale in JSON, with food or items, but I think what you’re talking about would require a compile. Again, I can’t say that 100%, but I’m pretty sure.