and has a deep caring side which is demonstrated in how he treats his sister and the fact at regular times in the book there are people who he empathises and sympathises with (the Head teachers daughter, Ackley, Jane). Holden really values the nuns for altruistically caring for others, and what he perceives as authenticity; desire for authenticity is very NF.
In terms of I/E, I think it's difficult to tell because Holden is depressed and that has a natural impact on whether or not you appear extroverted. He certainly has extroverted traits; he seeks out the company of others throughout the book, sometimes people he doesn't even know very well, and obviously has a wide circle of acquaintances. However, I think part of that is in hope they will elucidate things for him and help him to understand why he is as he is, and at other times he simply wants distraction from how bad he feels. I think he's possibly an I though, since he's very introspective, wants time alone, reads a lot, sometimes can't be bothered with humanity as a whole, and seeks deep meaningful connections on a one-on-one level. I think he is hesitant to share his inner world with others, which can also be an introverted thing. I am not sure socialising for the sake of socialising would appeal to him. The log cabin fantasy at the end could be seen as an introverted thing, but I think that's his idea of the ultimate way of cutting himself off from humanity in order to avoid pain. There's a great paradox throughout the book; Holden longs for people to understand and accept him, but equally he despises many elements of the human condition and isolates himself from people. He spends the book vacillating between the two, hence E/I being difficult to determine.
I see nobody has questioned if he's a P, I think that's pretty self-evident
I think this book is grossly misunderstood. Teenagers who say 'I love Holden, finally someone who understands me!' and adults who say 'What a whiny brat', in my opinion, miss J.D Salinger's point. I don't think J.D Salinger is endorsing everything Holden says. You're *meant* to recognise that Holden is a bit of a hypocrite and isolating himself from the world through a pseudo-superiority complex. I think you're meant to look beyond that and question why he is so lost, and it particularly relates back to unexpressed grief regarding his brother and other traumatic events. I can genuinely say that 'The Catcher in the Rye' is the only fictional book to change my life, not 'cause I agreed with Holden, but cause I saw elements of himself he was blind to that related to moi.