What is the author's style in Growing Up by Russell Baker?

Growing Up is an autobiographical memoir told in the first person, from Russell Baker's point of view. However, Russell doesn't strictly tell the story from his own perspective. He also narrates part of his mother's life, before he was born and when he was very young. He tells about his mother's relationship with Oluf, which he was largely unaware of at the time. Russell becomes a narrator of his mother's story during these parts of the memoir, often explaining her thoughts, opinions, and point of view as part of his narration.