DH has 4 DC, quite close in age. Youngest is 11.5 and has always played the baby of the family. Eg talks in a put-on baby voice, deliberately mis-pronounces words to sound "cute", and generally acts like a much younger child a lot of the time. He is still quite sweet-looking (and sweet-natured much of the time) but it's becoming harder to sustain this role now that he's nearly 12. But how do we help him to grow up, when he seems to feel his role in the family is to be the baby? He gets told endlessly to stop the baby voice, but seems to find it hard to talk normally sometimes. I know it's always best to praise good behaviour rather than constantly criticise baby-behaviour, but it seems rather forced to say "well done for speaking normally"
Any suggestions how you help the youngest develop a more mature identity? Do we just wait for him to grow out of it? He's quite small for his age too, so I fear may get into a similar role even with his school friends of being the baby of the group.