thanks so much, you have really set my mind at ease!
my son is also very intelligent but not a show off!so he keeps it to himself..I was doing art with them at school the other day and when the teacher asked a question ( that I knew he knew the answer to) he kept his arm down..I don't push him or he goes the other way.
further to your advice, his father and I are quite out-going and like doing crazy things but Joe is very reserved and 'the sensible' one in our family..which we do find amusing (and he does)and whereas we are practical and creative (I'm an artist, his dad has his own joinery business) we think he's going to academic I always call him doctor wills!!( which he loves)
Joe's class has 12 in it so its very easy to get feedback and keep in close contact to the teacher (especially as I volunteer to help)
thanks again for the reassurance!!