Didn't intend to be a tease or dangle the bait. Just wanted to point out that many assertions are testable. I will also add editorially that I personally believe that all testable assertions should be tested. Since gnomad asked - we find the "hit" rate to be exactly what one should expect from random chance. That is - exactly zero effect. BUT - LH makes an excellent point about the effects of experimental controls on experimental results. Sorry for the long cut and paste, but here is Feynman's version of what LH said above:
"...there have been many experiments running rats through all kinds of mazes, and so on — with little clear result. But in 1937 a man named Young did a very interesting one. He had a long corridor with doors all along one side where the rats came in, and doors along the other side where the food was. He wanted to see if he could train rats to go to the third door down from wherever he started them off. No. The rats went immediately to the door where the food had been the time before.
The question was, how did the rats know, because the corridor was so beautifully built and so uniform, that this was the same door as before? Obviously there was something about the door that was different from the other doors. So he painted the doors very carefully, arranging the textures on the faces of the doors exactly the same. Still the rats could tell. Then he thought maybe they were smelling the food, so he used chemicals to change the smell after each run. Still the rats could tell. Then he realized the rats might be able to tell by seeing the lights and the arrangement in the laboratory like any commonsense person. So he covered the corridor, and still the rats could tell
He finally found that they could tell by the way the floor sounded when they ran over it. And he could only fix that by putting his corridor in sand. So he covered one after another of all possible clues and finally was able to fool the rats so that they had to learn to go to the third door. If he relaxed any of his conditions, the rats could tell.
Now, from a scientific standpoint, that is an A-number-one experiment. That is the experiment that makes rat-running experiments sensible, because it uncovers the clues that the rat is really using — not what you think it's using. And that is the experiment that tells exactly what conditions you have to use in order to be careful and control everything in an experiment with rat-running."
So, we need to do a lot more staring experiments to find what clues the rats...I mean kids are really using. I suspect that those clues exist because as olddude mentioned above, a bit of law enforcement training enhances the effect.