Siobhan also says that if you close your mouth and breathe out loudly through your nose it can mean that you are relaxed, or that you are bored, or that you are angry and it all depends on how much air comes out of your nose and how fast and what shape your mouth is when you do it and how you are sitting and what you just said before and hundreds of other things which are too complicated to work out in a few seconds.

The Curious Incident of the Dog in the Night-time: Vintage Children's Classics (ed. Random House, 2012) - ISBN: 9781448139859