My DS is 6mths old and doesn't seem to show any interest in other babies whatsoever (well, he might look at them if they make a loud noise, but that's it!). I gather this is normal at this age, but I am keen to know at what age I should expect him to start to play/interact with his peers. When did your DCs start playing with others? Does it make a difference if they are an only child (as DS is) rather than having siblings?