MacGavin looked at him with the savage expression sometimes to be seen on the faces of the ignorant when confronted with what seems to them a new and difficult and rather mad idea.
William Plomer, “The Child of Queen Victoria”
Holden Caulfield, like J. D. Salinger himself and the members of the Glass family he wrote about in a number of short stories, has a genius I.Q. Holden sees things that average people cannot see. This is characteristic of all people with genius I.Q.s. He has already learned that expressing the truth as he sees it can make some people angry and can make other people think he is crazy. A good example of the problems he has can be found in Chapter 9, where he asks the cab driver:
"You know those ducks in that lagoon right near Central Park South? That little lake? By any chance, do you happen to know where they go, the ducks, when it gets all frozen over? Do you happen to know, by any chance?
He turned around and looked at me like I was a madman. "What're ya tryna do, bud?" he said. "Kid me?"
"No--I was just interested, that's all.
The cab driver's I.Q. would be classified as "Dull Normal." It is noteworthy that he both gets angry and seems to think Holden is a "madman." Holden has had such experiences innumerable times, including with the "normal" teachers at his school and the "normal" students. He seems defensive and apologetic when he asks the cab driver about the ducks, half-expecting a hostile reaction to a perfectly innocent question.
Holden doesn't yet realize that he is an "ugly duckling." He thinks he is dumb, partly because he has done so poorly in several schools. But he has a superior intelligence, and he reveals this unwittingly with his observations throughout his story. Opening the book at random, I find the following paragraph on page 87:
Then she left. The Navy guy and I told each other we were glad to've met each other. Which always kills me. I'm always saying "Glad to've met you" to somebody I'm not at all glad I met. If you want to stay alive, you have to say that stuff, though.
When he meets Mrs. Morrow on the train he is anxious to get along with her because he feels lonely and somewhat apprehensive about going into the city which is big enough and tough enough to intimidate anybody, much less a sixteen-year-old boy. He would like to prolong their conversation, and he knows he mustn't say anything to offend her. His intelligence is evident in the way he understands her care and concern about her son and the way he spontaneously makes up a story about the obnoxious boy which is the complete opposite of Ernest's real character.
Is Holden being "phony"? It seems to me that the people he judges to be phonies are usually those who don't realize they are phonies. Holden tells many lies, but he is as sincere with the reader as he knows how to be.
Holden's behavior with Mrs Morrow is typical of Holden, if you need a quick word to describe it. He does three things he often does.
First, he escapes responsibility and an awkward situation by lying. He tells Mrs Morrow he is someone else, using the janitor's name instead of his own. He just doesn't feel like answering questions about what happened to him at Pencey.
Second, Holden creates. Holden is bored. Sometimes he plays mind games, but in this case he tells stories to Mrs Morrow. He is articulate and creative, and he uses his creativity to fight boredom.
Third, and most important, and what the novel is really about, Holden helps Mrs. Morrow. He puts her mind at ease and reassures her that her son is well-liked and is getting along well at school. Her son is no longer innocent, nor is his situation. No one at Pencey lives in innocence. But Holden, in effect, tells Mrs. Morrow that her son is.
Retaining innocence is what Holden is about. And for at least a little while, he helps Mrs. Morrow do just that.