For speculative fiction writers it is often said that we need as much authenticity as possible on our books in order to make our created worlds believable. I keep running into situations, however, where being authentic hurts the story for some readers.
The most recent example of this has to do with the second chapter of my science fiction thriller, in which I use Russian mafia antagonists. I tried to make these characters as authentic as I could, based upon my extensive experience with Russian Mafiosi. They were all over the place in Moscow when I lived there. You couldn't even tell who was genuine and who wasn't, because there were so many young men copying their styles.
The problem is that some readers have complained that the Mafiosi in my story are too clichéd, yet that is precisely what makes them authentic. Russian mobsters, at least in the 90's, seemed to take pride in imitating famous mobsters of the past, such as Al Capone or the Godfather. Other than their clothing (they seemed to like track suits and flat-top haircuts), they didn't try to be unique. The more outlandish and unusual I make my Mafiosi, the less authentic I am being. If my Mafiosi seem overly brutal and speak like thugs, it's because that's the way they really behave in my experience. I suppose many would say that the story is what matters, so forget being authentic and just make the characters memorable. I do want to make the characters memorable, but I prefer to do it within the constraints of what I know these folks are actually like in reality.