Supposedly, if your position in the SERP (search engine resulting pages) slip or fall, it is most likely due to duplicate content. It’s a total myth. That is not the case at all. It’s actually a lot of varying factors, but that is not the topic for today’s discussion. Today’s discussion is simply whether Google penalizes you for duplicate content or not.

Well, straight from the horse’s mouth (I like saying that a lot):

Duplicate content. There’s just something about it. We keep writing about it, and people keep asking about it. In particular, I still hear a lot of webmasters worrying about whether they may have a “duplicate content penalty.”

Let’s put this to bed once and for all, folks: There’s no such thing as a “duplicate content penalty.” At least, not in the way most people mean when they say that.

Source: Google Webmaster Central

I’m sure the belief of duplicate content penalty will still continue to circulate for many years until that idea is finally lost to the ages of time. People once believed that the world was flat. People today still think Michael Jackson is black. It just takes time.