What interview with a Mad Men actor gave you greater insight into the psychology of the character?
Like Jared Harris on the WTF podcast explaining that he understood that Lane was a middle class Englishman with an inferiority complex towards his social betters at PPL (Powell, Ford). And as a result he accepts their lesser treatment of him out of a sense of "duty" and "knowing one's place".
Or that Lou Avery is meant to be the mediocre placeholder middle manager that's very common in real work-life. Someone who won't crash out like Don but won't dazzle anyone either.