Christopher Boone ends the story by enumerating his ambitions for the future and explaining that he knows he can achieve them because of all that he has accomplished during the course of the book. Christopher's ambitions are entirely admirable. He wants to study, to learn, to become a scientist, and to work on problems worthy of his first-class mind.
It is clear that society needs people like Christopher. He is able to see patterns and make deductions when other people cannot precisely because his mind works in a different way from most people's. The unusual nature of his mind, however, means that the world is very often an uncomfortable place for him, as it is on his harrowing solo journey from Swindon to London.
The social significance of the novel lies in the clarity and empathy of Haddon's depiction of the way Christopher sees the world. If we want people like Christopher to help society solve its problems, we should probably try to make life as easy and comfortable as possible for them. Fortunately, Christopher is extremely good at explaining how he feels and thinks. The book is full of misunderstandings, but the reader is often able to understand Christopher and, having read the book, would have a much better idea of how to behave when encountering someone like him. Thus, the book is itself helping to create the cure for the lack of understanding it describes. Therein lies much of its social significance.