According to Henrik Vejlgaard, the author of Anatomy of a Trend: "There is nothing mysterious about it and it never just happens out of the blue; though it may sometimes appear to be so. That it is a social process means it's created by human beings. A trend becomes a trend through a constant cycle of innovation and emulation. It's the way people embrace one another and interact with one another. People are obsessed with trends because joining a trend means your part of a group; you are in, you belong.