Here’s a thing that trips up almost everyone, including adults who should know better. You’re researching something and you find the same fact on ten different websites. Ten sources all saying the same thing — that feels solid, right? Except if all ten of those sites got that fact from the same single article, you don’t actually have ten pieces of evidence. You have one piece of evidence, photocopied ten times.
This pattern is sometimes called source copying or citation cascading. Source A makes a claim. Source B cites Source A. Source C cites Source B. By the time you’re reading Source G, the original claim looks ancient and unshakeable — but nobody along the way actually went back and checked whether Source A was telling the truth. Research published in PMC shows this is how false facts can get “canonized” — repeated so many times across so many places that they start to look like established truth, even when the original claim was never properly verified.
And repetition itself can mess with your brain. Studies on misinformation suggest that people tend to become more confident in a claim — and more susceptible to believing it — when they encounter it repeatedly, even when the repetition traces back to the same original story. It’s not three independent witnesses confirming something. It’s one witness with three different outfits on.
So what do you actually do with this? When a claim matters — like you’re using it in a paper, making a decision based on it, or sharing it with other people — try to find the original source. Most articles that cite a fact will link to or mention where they got it. Keep clicking back. If you can’t find a primary source (an actual study, an official record, a firsthand account), that’s a red flag worth paying attention to.
It takes maybe two extra minutes. And it’s the difference between actually knowing something and just having heard it a lot.