Personal anecdotes, perhaps?
How he keeps recalling past instances and calling people phony.
Like something about Stradlater and the suitcases incident.
Or perhaps even the fact that as he does not fulfil the requirements of any paradigm of belonging (except for family perhaps - Phoebe), Holden cannot achieve a stable sense of belonging and thus feels alienated and disdain. Although at the end it is his close relationship with Phoebe that makes him happier, I guess.