I don't think Rbert smiled for quite a while but he was a premmie so everything seemed to take ages until he reached his 'birthdate'. He also has a bigger than average head. He is a smartie
I wouldn't worry about Autism. I remember a quote from Sherlock Holmes which went something like 'a man with so large a head must have something in it'. He was talking about a professor with a large head.
I think every baby is different. Try not to worry. enjoy your lovely baby, best to you Magoo :0 great to hear from you, THK