I can't believe something so simple could be so effective!

(or: late night infomercial rubbish)

The title is the catchphrase from a certain infomercial for a certain shoe insert, you know the one. Another notable comment: "Could it be that it creates a force field that ..." Answer: no. It cannot possibly be because that's not what "force field" means.

What they do is show you loads of people doing something called a "balance test" where subjects are easily shifted off balance unless they are wearing the special inserts. Here is what it looks like:



... this is an old con exploiting misconceptions about how well we balance, as well as a bit of basic physics. In general, humans are unstable - particularly with their feet together - which is why toy soldiers need a wide base to stand up. We balance by shifting our weight and generally moving about.

Look carefully at the video again: the subject is in an unstable, but sustainable, position. In the first test the seller pushes down and a bit away from his body, thus directing the force away from his feet, pulling him over. In the second, she pushes down and towards his body, basically directing the force down to his feet and improving his stability. Nothing to do with the inserts.

This method has been used to sell a wide variety of junk. It is so effective it works in even less stable stances like, standing on one leg. Here's how it generally works:



Skeptics have been facing this sort of thing for a while now. While the basic testing method (double blind) shows up the fallacy, it is generally not very convincing if you don't know how it works. You just can't believe such a simple con can be so effective!

This is because, if you have experienced the test, it is very convincing. We are just not used to doubting our own experiences, and it is unpleasant to do so. On top of this, skeptics deliberately avoid using methods which encourage the willing suspension of disbelief. Skeptics want you to question everything, the advertiser does not. So the skeptic will always appear the less believable of the two.