Because "narcissism" means different things to different people and in different domains (e.g., pop-culture and social science research), the term should be used with great caution in informal social contexts, in the media, in HR assessment and employee management, and in scientific research.
Are these behaviors all manifestations of one causal factor ("narcissism") or simply a grocery list of traits and behaviors being called "narcissistic" because of some unpleasant connection with and manifestation of the "self"?
In other words, is "narcissism" a (scientifically) grounded explanatory concept or merely a descriptive one, i.e., is it a driver of the traits and behaviors called "narcissistic" or merely a label for the set of those compiled on the basis of some descriptive similarity, such as being unpleasant (or weird) and self-focused?
If it explains those behaviors, ways to prevent or control it may be more obvious and any correlations among the traits may make more sense. Moreover, such explanations would provide some serious insight into why these traits and behaviors exist, correlate and seem so prominent.
Accomplishing that seemed to be the ambition of (early) psychoanalysts, whose diagnoses were matched with theories about the causes of narcissism (built into psychoanalytic definitions of "narcissism", below); but that's not such an important goal of modern and apparently more numerous or influential behaviorists (whose focus is on behaviors, not on "hidden" causes). It certainly is not a priority in pop-culture, casual narratives about narcissism either.
