I'm sure I read/ heard somewhere that children born in summer can take many years (right up to 11 or older) to 'catch up' with their oldest peers?
Do school entrance exams at 11 take any account of 'immaturity' do you think, or has it really become irrelevant by then?
DS2 is a late August boy, and although he's only 6, the gulf between him and his older peers is still massive - seems hard to imagine it will have disappeared completely by Year 6!