WE are all tribal, author and law professor Amy Chua says in the opening lines of her new book. We crave bonds and attachments, which is why we love clubs, teams, fraternities and family. But the tribal instinct, she goes on, is not just an instinct to belong – “it is also an instinct to exclude”.http://www.heraldscotland.com/news/16079141.The_Tiger_Mother_out_to_burst_our_political_bubbles/