Reality TV viewing & narcissism

This post from Medscape discusses a recent study that purports to show a link between narcissistic traits and viewing certain kinds of reality TV programs. While causality, as such, is not addressed by the study and actually statistical significance is lacking, the general observation is that the relationship between the activity and the trait(s) may be a sign of re-norming. There is no question that media consumption influences such norm-resident factors as attitude development and belief systems. Still, the unsolved question here is: Do people tending to have these traits self-select for viewing this type of content, or does viewing this type of content influence trait formation?