Find him a friend. You need to work hard on this. Throw a weekly party if you have to. Buy video games, ice cream, chips, movies, comic books, whatever he and his friends are into. Invite kids in his class over, maybe one at a time, and notice the nice ones. Invite those nice ones over more often. Pay attention to what they like to do and not what you want them to do. Please take an active role on this.