The first example that shows Holden is growing up is when he goes to Phoebe’s school. He notices vulgarity on the walls and it drives him crazy. Holden, then “rubbed it out.” This suggests that Holden is maturing because he doesn’t want Phoebe and the other children to see profanity on the walls. Later on, at the Museum of Art, Holden tells Phoebe that he is going to run away. Phoebe begs Holden to take her with him and Holden says “You’re not going.” Holden wants what is best for her. He wants her to be safe at home with the family.
At the end, Holden and Phoebe go to the carousel. Holden is happy when he watches Phoebe on the carousel. “I was damn near bawling, I felt so damn happy.” Holden has grown up because he is watching like a parent standing off to the side. He refuses to get onto the carousel and that shows he is growing up. He is not a child anymore.
J.D. Salinger uses the theme of growth in The Catcher in the Rye to show the process of going from childhood into adulthood. Holden follows the long path into adulthood, but he gets there in the end. He has grown up¬.