During a conversation with Mrs. Morrow, Holden uses the alias Rudolf Schmidt and pretends to be a janitor at Pencey Prep. Holden's excuse for using the alias is that he didn't want to give Mrs. Morrow his "whole life history." When Holden interacts with three young ladies at the Lavender Room, he uses the alias Jim Steele. Holden mentions that he made up the name "just for the hell of it" and attempts to impress the women.

Holden once again uses the alias Jim Steele when he interacts with Sunny the prostitute. One can assume that Holden uses this alias to protect his identity since he is breaking the law. Given Holden's extremely low self-esteem and numerous insecurities, one could argue that Holden fabricates his identity and uses aliases as a way to psychologically escape his present circumstances.

For example, the name Jim Steele conjures the image of a strong, confident man, which is the complete opposite of Holden's meek personality. It is also evident that Holden experiences a thrill from manipulating people and influencing others. As a relatively powerless teenager, Holden finds it exciting to deceive others. Given his narrow perception of adults, he may also be experimenting with deception, which he believes is an intrinsic quality of adults. Overall, one could argue that Holden uses fakes names to distance himself from his present circumstances, experience the thrill of deceiving others, and adapt himself to the competitive world of adults.

Holden uses pseudonyms when speaking with others throughout The Catcher in the Rye for a couple of reasons. First, he doesn't want to associate his own name with some of the things he does—such as meeting with a prostitute. He doesn't want to be connected with these actions, so he uses an alias in the event that word gets out about it.

In addition, however, he has a deep dissatisfaction with his own life and a desire to make it more interesting. Because of this, he begins to weave false tales of his own life and uses fake names with other people to go along with the lies he tells. He spins stories of illness and of excitement for both pity and for respect. He wishes to gain empathy from and a connection with others without having to actually be vulnerable, so he creates fake lives in his interactions with others.

It's ironic that Holden should always be going around calling other people "phonies" when he frequently adopts false identities himself. However, this isn't a simple case of hypocrisy on Holden's part; rather, it's a sign that he's deeply unhappy with himself.

This is a young man at a difficult age; he's trying to find his way in the world, and he is desperate to construct an identity for himself. Most young people of his age find that hard enough, but for Holden—with his mental health problems—it's almost impossible. Putting on a false identity briefly allows Holden to escape from himself, a self he's come to hate even more than the numerous "phonies" who make his life such a chore.

Holden feels dissatisfied with his life and also with almost everything he experiences. His anger, which he doesn't fully understand, is shown in his contempt for anything that annoys him, or anything that he sees as "phony." One of the ways in which Holden expresses this is to use aliases when speaking with others; he is not self-assured enough to use his real name, but he also is contemptuous of others and thinks that nobody will know or care if he lies. When he introduces himself as "Jim Steele" to Sunny, the prostitute, it seems as if he is trying to boost his own confidence; the name is as silly as he finds the situation, and he comes across as a timid boy rather than a street-smart man. Another example comes when he speaks with Mrs. Morrow on the train:

"Oh, how nice!" the lady said. But not corny. She was just nice and all. "I must tell Ernest we met," she said. "May I ask your name, dear?"

"Rudolf Schmidt," I told her. I didn't feel like giving her my whole life history. Rudolf Schmidt was the name of the janitor of our dorm.
(Salinger, The Catcher in the Rye)

Interestingly, from that single lie Holden begins spinning a whole string of lies to Mrs. Morrow, from his friendship with her son to a tumor on his brain. He cannot connect with her on a personal level, although he feels attracted to her, and so he lies to sound interesting. His use of aliases indicates that on some level he is ashamed of his life and behavior, and he wants to become a different person: more interesting, more honest, less angry, or simply less like the self that he unconsciously dislikes.