How do you know that J. D. Salinger wants us to see that Holden is not a destructive narcissist?
By introducing Holden as a socially and academically disengaged person who is experiencing his failures through a membrane of bitter humor, Salinger sets up the narrator as a reactionary figure. We see his self-defense at work right away. These defenses continue to distance him from a world that is, for him, foreboding and increasingly hopeless. These are not the hallmarks of narcissism but rather the marks of despair.
Holden's character is sympathetic in large part because of a strong undercurrent of tenderness, nostalgia, ironic innocence and protective instincts. But the careful reader will note that Holden's negativity has a specific source and also that he does not seek out destruction.
In his confused state, Holden positions himself as a child in need of protection before running off the cliff (in the central metaphor of the text) and as the child-shepherd ready to save others. The destructive aspects of his character might be best attributed to the idea that Holden cannot effectively place himself in one role or the other and so suffers alone in between.
On the first pages of the novel, Holden's narrative begins with a presentation of his disdainful attitude in a depiction of his negative evaluations of family, movies and Pency Prep, but quickly following these judgments the narrative speaks to Holden's own failings.
The introduction to Holden's character consists of a snapshot of his attitude and, critically, a clear sense of his flaws, which are connected to an inability to focus and to engage academically and socially.
In successive paragraphs, Holden explains why he is standing on a hill, away from the big sporting event taking place at Pency, and how he has been kicked out of school. He mistakenly left the fencing team's equipment on the subway. The "whole team ostracized [him] the whole way back on the train. It was pretty funny, in a way." And he has been unwilling to "start applying" himself in time to avoid being "given the ax" by Pency Prep.
Holden's response to both of these events is a defensive disdain that reads like highly intentional indifference. While the tone of the narrative is snarky and irreverent when it concerns the world around him, it is superficial and defensive when it deals with Holden's failings.
In this way, Salinger situates the reader within Holden's own point of view rather explicitly and develops a sense of insulation within Holden's thinking that distances the narrative from the outside world. We might sympathize with the fact that this character is a young man who recently suffered the loss of a sibling and who is now socially isolated, academically disengaged and full of bitterness.
Salinger makes the reader fully aware of Holden's protective feelings toward figures of his childhood (his sister and his friends Jane and Sally) and we see that he is in real pain (emotional and psychological). Salinger's choice to situate the reader inside of Holden's point of view effectively means that we participate in Holden's self-defense against the forces that threaten him.
Despite Holden's penchant for dismissing the parts of the world he does not care for, we also see that he thinks often of other people. He is not only thinking of himself as a narcissist would. And he is not dismissing the world in ways that are comparative in reference to himself or even to his tastes. Instead, Holden is reacting to a world that, for him, has lost its sheen of wonder. It is a world where things go wrong and people die.
Reflecting on Pheobe's Saturday trips to the museum, Holden gives his emotionally charged perspective a pointed synopsis:
"Certain things they should stay the way they are. You ought to be able to stick them in one of those big glass cases and just leave them alone. I know that's impossible, but it's too bad anyway."
When Holden asks the cab driver about where the ducks go in winter, he is not asking with childish imagination and wonder. He is asking out of concern. This painful aspect of Holden's character is subdued, to some extent, by the first-person narrative style as Holden's mind is characterized by attempts to insulate himself from the depth of his real feelings.