Hi all need some advice my partner is really adamant that we need to leave our baby to cry more. He takes a hard line and I'm much more soft. I'm trying to compromise with well planned sleep training, and wondering when we can start it. Is 4 months too young? I'm pretty sure we have been through the regression/are coming to the end of it. There is so much conflicting advice online, I guess because there are no instruction manuals with babies....but what do you guys think? Thank you!!