Children's literature offers a generally positive portrayal of librarians as knowledgeable, helpful, amazing, and friendly, becoming more positive over the course of the 20th century. Adult literature, however, portrays the profession more negatively. Between these, portrayals of librarians in young adult fiction are neutral to negative. Here librarians are predominantly female, middle-aged, usually unattractive in some way, and mostly unmarried. Personality is mixed between positive traits such as intelligence, likeability, and kind-heartedness; and negative traits such as strictness, timidity, excess fastidiousness, and eccentricity. While some provide assistance to the main characters, several are the villains of the story. Duties generally include reference, but may only show clerical tasks; however the amount of technology used by librarian characters has increased over time. Ashanti White, author of the 2012 book, "Not Your Ordinary Librarian: Debunking the Popular Perceptions of Librarians", wrote that the shushing buttoned-down, older librarian was the most common depiction of librarians, in fiction, followed by the sexy librarian, stereotype.