Definitely varies with each chin, but mine became very comfortable and bonded around 3-4 months in. Some need the human bond less than others, they're happy bouncing about in their own world and I'm fairly certain their human could be replaced and they wouldn't notice - but my more intelligent chins definitely took their sweet time to get to know me and it has been rewarding spending each day with them since that trust was fully established. It is, of course, an ongoing practice of bonding and care.