When Kahneman gave a presentation to the Israel Air Force about the psychology of training, he claimed the virtues of rewards verse the negative impact of punishment. One seasoned instructor replied: "On many occasions I have praised flight cadets for clean execution of some aerobatic maneuver. The next time they try the sasme manuever they usually do worse. On the other hand, I have often screamed into a cadet's earphone for bad execution, and in general he does better on his next try. So please dont tell us that reward works and punishment does not, because the opposite is the case."

What is the possible purely statistical cause of the observed phenomenon that has nothing to do with feedback?