Definition
This device predates written literature. Poets use it because our minds naturally interpret faces and intentions in everything around us. When poets tap into that instinct, abstract concepts become immediate, and inanimate objects feel alive. A reader who might not think much about "the passage of time" can feel a strong connection when Time is portrayed as a thief picking your pocket.
Personification serves multiple purposes. It makes an idea tangible—you can envision a figure, hear a voice, or sense a presence. It creates emotional stakes that might not otherwise exist. Additionally, it allows a poet to condense a complex relationship into a single image: if the sea is described as "hungry," you grasp both its power and its indifference to human life in just one word.
It's important to differentiate personification from the broader category of metaphor. While all personification is a type of metaphor, not every metaphor is personification. The test is straightforward: does the non-human entity possess a specific human trait? If so, you've identified personification. If the comparison goes another way—like likening a person to a stone—that's metaphor without personification.
Poets ranging from Homer to Emily Dickinson to Langston Hughes have employed personification, highlighting its effectiveness across various eras and styles because it connects with something fundamental in how humans understand the world.