What is the narrative hook in Black Like Me?

Griffin begins his journal entries by explaining that he has always wondered what would happen if a white man became a black man. He questions the adjustments a person would have to make. He wants to know what it is like to experience discrimination that is based on skin color. Griffin writes that his questions were sparked by a report that he read. It said that the suicide rate among southern blacks had increased. Griffin wonders if this is because blacks are actually killing themselves, or if it is because they are giving up on life.