The film is based on Pete Docter's experience with his own daughter. When she was 11, he noticed her go from a happy girl to a moody preteen.
There's a scene when the family is at the dinner table; the dad is thinking about sports, and the wife says, "Isn't that right, honey?" to get his attention. This comes from Docter's own experience.
Riley and the family move from Minnesota to San Francisco; the director is also from Minnesota and lives in the Bay Area.
Camera details reflect Riley's life; she's often out of focus when she's upset about something.
In Minnesota, she is framed in the middle of the family 90 percent of the time; in San Francisco, she's not, which reflects how the family is going through problems.