Conformity and social class was a huge issue in the 1950s with society putting a lot of pressure on what you were "supposed to do" the socially acceptable way that society strongly encourages and frowns upon if not.
J.D Salinger challenged conformity throughout the novel through the main character Holden who was seen as a "nobody" as he rebelled against what society thought was acceptable and what you were "supposed to do" .
Conformity put pressure on people to finish school , get a stable job, get married and have a family. It was also known as the "American mold" . Holden however did not want such things and was judged harshly and thought of as "a loser".
In the novel teachers and friends try to change Caulfields attitude/ get him in line to make him fit in with societies expectations. E.g.
"Life is a game, boy. Life is a game that one plays according to the rules."
This quote talks about life as a 'game' needed to be played by the rules however these rules were just unnecessary pressure that society created. And throughout the novel
Holden was seen as a delinquent as he flunked out of school and didn’t keep up to the expectations and social class that was thought to be important. "I wasn't supposed to come back after Christmas vacation on account of I was flunking"
A constant phrase Holden uses is " I wasn’t supposed to " or "I'm meant to" showing how he rebelled against what he was "supposed to do " on a regular basis .
J.D Salinger questions conformity by showing through Holden that conformity is just commercial unnecessary and "phony" . I believe he did this to prove you are in control of your own future and don’t have to be molded so that society agrees however you can make your own "rules" to your life .