Multiperspectivity, Multiple Narrators, Multiple Points of View, Multiple Voices, Rounded Characters: Persons without multiple personality could not do it.

Since you could not intentionally create your own personality—including its perspective and point of view—it is a good thing that your brain knew how to do that, and did so.

In childhood, you can see the brain practicing its ability to create personalities in the normal phenomenon of imaginary companions.

In most people, one personality is enough, so as the person grows up, additional personalities are no longer generated, and the ability to do so is lost.

However, if there is childhood trauma, the ability to generate extra personalities may be maintained for the rest of the person’s life, a condition known as multiple personality.

In a small minority of cases, the multiple personality causes distress and dysfunction, and is a treatable mental illness. In a majority of cases, it does not cause distress or dysfunction, and may even be an asset; for example, in writing novels.

Multiple personality enables novelists to have multiperspectivity, multiple narrators, multiple points of view, multiple voices, and rounded characters.