Literary age groups

Literary age groups refer to the artificial demographic groupings people use to for the written word. Since there is no objective standard, I'm using my one for this site. My groupings include:

Group	Description
Baby	Babies, toddlers, and other children who haven't yet learned to read. These books focus on elementary learning like colors, shapes, textures, etc.
Early Children	Children who are beginning to read, but still aren't ready for complex stories. These books use simple vocabulary, and deal with understanding emotions and basic concepts.
Children	This group is for children who have moved onto longer chapter books which deal with more interesting and complicated concepts than early childhood books.
Teen	Books for teenagers who can handle longer stories with bigger words and more complex themes. These books tend to focus on coming-of-age tales, interpersonal relationships, and the like. This group is commonly referred to as "young adult fiction."
Adult	Books which discuss complex issues and relationships which appeal to adults.