An important part of developing a characters is showing your readers how they view and interact with their world. Cynical characters are going to think and talk about the world one way, while more optimistic characters are likely to think and talk about it in another. Your characters’ attitude will be reflected in their speech, and it will shape the language of any chapter written from their point of view.
Personification, a poetic device we use frequently in everyday speech, provides us with a window into a character’s outlook on a situation. A frightened heroine of a Gothic novel, for example, might describe a tower with windows that leer at her. In this case, the personification of the setting mirrors the personality of a licentious Gothic villain. This helps the writer establish the theme of the heroine’s struggle against the violence that threatens to shape her destiny.
At its core, personification is the art of giving human traits to something non-human. This gives characters a way of interacting with their world on a symbolic level. In a sense, personifying a concept helps your character understand it. Some characters (Shakespeare’s Hamlet comes to mind) may even use personification as a means of coping with a situation that they are unable to control. When your readers can get a firsthand glimpse at one of the mental processes your character uses to navigate their world, it becomes easier to get engaged with a character and stay interested in their development.
Poets use personification to express their unique viewpoints on the world; you and I use this poetic device as well in our everyday speech. It makes sense for your characters to think about concepts in terms of human traits, and the traits that your characters see in things tell your readers a good deal about their personalities.