David Hiltbrand, columnist for the Philadelphia Inquirer and mystery novelist, wrote a thought-provoking article recently about the trend in pop culture towards more gratuitous expressions of violence and brutality. Sarah Weinman linked to the piece and touched off an interesting discussion about it, focusing on the literary world.
When it comes to television and film, relaxed standards have clearly, I think, allowed filmmakers to depict content on-screen that previously would not have been allowed. (Note that this is true regarding violence, but not sex.) Furthermore, advances in technical sophistication have made it possible to show things in a hyper-realistic manner that wouldn't have been possible even twenty years ago.
With regards to the themes involved, whether torture, mayhem, serial murder, etc., I don't think much has changed. And I believe this is true for books as well. If anything, there are some themes, especially those involving violence towards women and children, that might even be a little harder to deal with these days than before. (Mickey Spillane, for example, got away with some real nastiness towards women that probably wouldn't fly today with a mass audience.)
However, if the themes have remained largely the same, I do think that the descriptions of and attitudes towards those themes have changed. The language and imagery used in mainstream books is stronger than it once was. Previously, you might have found such material in an obscure pulp novel, but now we're seeing it in highly-promoted and publicized books that land on the bestseller lists.
Now, I'm the farthest thing from a prude. I don't think I've ever read anything in a book that shocked or grossed me out. So for my purposes, I don't particularly mind it. But I do get peeved when I see an author who appears just to be throwing that stuff in there for shock value. It might make for a nice marketing ploy -- "Look at the nice woman writing the awful things!" -- but it doesn't necessarily make for good storytelling.
Another thing I have a problem with is when novels take too much pleasure from dwelling on their blood and gore. When you start to feel the author lingering over such a scene with almost reverential (or sexual) glee, it definitely becomes a turn-off. (This is how many people felt about Thomas Harris' Hannibal.) I don't mind it because I'm offended. I mind it because it's bad writing. Such passages are not storytelling; they're voyeurism, cheap and lurid. And I'm no more interested in reading that than I am in peeping in someone's window.
As always, talented writers use their themes, images and language in service to the story. They don't do things simply in an effort to shock the reader. Even if the purpose of the story is to shock, a skilled writer will still ensure that what happens in the story is an organic and necessary part of the story. The content might be shocking, but the author will have earned that reaction, and the story will be stronger as a result, not diminished.
It's easy enough to write passages filled with murder, mayhem and mutilation, all dripping with blood, guts and ichor. But if it's not a logical outgrowth of the story, fitting in with the book's overall tone, style and theme, then what's the point? It's not going to shock; it's simply going to bore. Such a writer isn't worthy of outrage. Just throw the book away and move on to an author who cares about the story they're telling.
