DS1 has always been a serious child, even as a baby, but recently he has become more and more sullen. His default expression is often so moody it's actually laughable. My worry is that it's stopping him from making friends - other people's children seem like little rays of sunshine next to him. He also never wants to get involved with games that other children are playing, but would rather play on his own. Has anybody else got a child like this? How did you cope and how did you encourage them that this is not the best way to get through life?