ackley

Ackley and Holden may seem like opposites, but they are quite alike. They both have tendencies as outsiders, seeing as they are the only ones who did not go to the big football game that afternoon. Ackley and Holden are both lonely inside and have developed defense mechanisms as being rude, rebelious and disgusting. Ackley helps Holden feel at home at Pencey, without Achley Holden would be completely alone.

The characters are also representative of the superficialness taking place at Pency. Hence the nail cutting and pimple popping

In literary terms it's called a foil.

I think that from a psychoanalytic perspective Ackley is a projection of Holden's and combines all the characteristics that Holden strives to get rid of. So there' s a division between his persona, that is depicted throughout the book and his actual behavior and feelings, that are more like Ackley's.

I'm thinking on this idea at the moment and I find it useful. So I hope it helps you too