The diverse relationships that Holden clearly has with others serves to show how unstable his character is, even though he himself is unaware of this. He ranges from outright hostility towards certain individuals to love and affection, which is shown most clearly in his relationship with Phoebe. However, the common theme that can be seen in Holden is that he always tries to reach out and form relationships, no matter how he actually feels about the person, only to find that for whatever reason there are problems with forming that relationship. Note how he talks about Stradlater when he is quizzing him about his date with Jane and what time he got her back, whom Holden clearly likes a lot:
He was sitting on the edge of his bed, cutting his goddam toenails, when I asked him that. "Coupla minutes," he said. "Who the hell signs out for nine-thirty on a Saturday night?" God, how I hated him.
What is interesting about this relationship is that even though Holden at one level clearly loathes Stradlater, he had previously completed Stradlater's homework for him and continues to stay in his presence, even though it is mainly to annoy Stradlater. Holden seems to try and form relationships whilst simultaneously pushing people away from him through his prejudice and hatred of "phoniness." This of course shows the reader a lot about his character and the various challenges that he faces.