Holden Caulfield explains in the first chapter that he is not going to return to Pencey after the Christmas break, which is starting in just a few days, because he has been expelled.
I forgot to tell you about that. They kicked me out. I wasn't supposed to come back after Christmas vacation, on account of I was flunking four subjects and not applying myself and all. They gave me frequent warnings to start applying myself--especially around midterms, when my parents came up for a conference with old Thurmer--but I didn't do it. So I got the ax. They give guys the ax quite frequently at Pencey. It has a very good academic rating, Pencey. It really does.
Holden never blames anybody but himself. He later explains that he was not flunking English because, for one thing, he had a knack for writing compositions. This is very significant because Salinger makes it seem plausible that a sixteen-year-old high-school dropout could write an entire novel like The Catcher in the Rye, which is full of incisive observations about people and about life. Holden has been compared to Mark Twain's Huckleberry Finn, but it is far more likely that Holden could write a novel than that Huck Finn, who has no formal education at all, could write one.
Holden never explains why he seems incapable of "applying" himself. He has already been expelled from two other elite private schools, Whooton School and Elkton Hills. He just isn't interested in most of the subjects taught in school, and he either can't or won't apply himself if he isn't interested. In his hilarious meeting with Mr. Spencer in the second chapter, his elderly history teacher reads him the note he attached to the exam paper on the Egyptians.
DEAR MR. SPENCER [he read out loud]. That is all I know about the Egyptians. I can't seem to get very interested in them although your lectures are very interesting. It is all right with me if you flunk me though as I am flunking everything else except English anyway. Respectfully yours, HOLDEN CAULFIELD.
The Catcher in the Rye seems to be an autobiographical work. J. D. Salinger probably had the same kinds of trouble in school as his alter-ego Holden Caulfield. Salinger's problem as an adolescent was probably that he had a genius I.Q. This can be deduced from his phenomenal writing ability and especially from all the stories he wrote about the Glass children, who were all geniuses. Harold Ross, editor of The New Yorker, devoted entire issues of the magazine, from cover to cover, to Salinger's stories "Franny" and "Zooey." Anyone who wishes to understand Holden Caulfield should refer to the stories about Seymour Glass, including "A Perfect Day for Bananafish," as well as those about Franny Glass and Zooey Glass.
Having an I.Q. of 150 or even higher is not necessarily an asset in school. Such a person can easily become bored with a curriculum that is tailored to students with only average I.Q.s. Since the time represented in The Catcher in the Rye, schools have made progress in identifying students with exceptionally high intelligence scores, and some are offering special accelerated classes to such gifted individuals.