I find myself dealing sometimes (and indeed am guilty) of a phenomenon that I would like to call “Presumed Backing.”
It is neatly summarized as follows: the more people approach you with a certain fact, the more likely you are to believe it is true, because you implicitly believe that there are an increasing number of “backing facts” not explicitly stated. If John tells you “Sue ran down the street naked!” and Jane tells you “Sue ran down the street naked!” you may begin to believe that Sue did run down the street naked. If a third person tells you the same, your credibility in the event increases. Why? Because you presume that each person has verified this event to have happened and you presume their verifications to be independent.
The interesting thing about Presumed Backing is that it can achieve critical mass. With a sufficient number of initial believers in an event, a few even relatively skeptical individuals may be won over through sheer numbers. As these skeptics fall, doubt is introduced into ever higher levels of skeptics, letting a convinced populace truly replace the presentation of facts.
This is how rumors get started. A devious individual plants an idea into a handful of impressionable peers’ heads. These together can then begin to sow doubt into the minds of the populace, and so on and so forth. Once a rumor is widespread, we often implicitly believe there to be equally wide-spread substantiation of the allegations, even when the
truth may be that the ill-advised “fact” had a singular author.
This is also how chain mail works: you receive a letter (e.g., “A little boy is dying of cancer…email this to a dozen of your friends and the Red Cross will give a penny for every ten people that get this email”) directly from a friend. You are much more likely to presume
the email to be factual since it came from someone you know: you presume there exists backing evidence, and you might go forward the email on yourself.
Once you recognize the process of Presumed Backing, it’s easy to stop. All you have to do is inquire as to the direct evidence. “Who saw Sue run down the street naked? Are they sure it was Sue? Are they sure she was naked?” — asking Sue herself might not be a bad idea either. This eliminates the false assumptions about the strength of the verification
undergone by your peers and will help you from contributing to rumors and other “false memes”.
If you redistribute information, it is wholly your responsibility to check that information for correctness.