Magic tricks are all to do about the independent variable, that is the thing or things you manipulate to get an intended result. But magic is all about one thing, namely the unlikely or impossible variable that the eye does not see but cannot resist believing. Of course the magician doesn't allow you in on the trick, but nonetheless lets you know it is a trick. In other words, there is more than one independent variable than meets the eye, and indeed, as the magician cautions, seeing should mean disbelieving.
As any magician will tell you, the folks who are easiest to fool have the greatest interest in being fooled, or in believing that sleight of hand is of slight importance, and that magical accomplishments reside in the import of magic words. Indeed, scientists are the easiest to fool mainly because they have a vested interest in extraordinary causes. So, rather than believing that crop circles are caused by pranksters, that ESP is a mere magician's trick, or that 'hypnotic' behavior can be caused by ordinary motives, a 'scientist' would demur, and write articles, found journals, and avert the eyes of millions to a new intellectual movement that following the footsteps of Galileo and Darwin will revolutionize the world. And so in the large we have the trick of human behavior reduced to a magic word that is no more than a metaphor, and 'reinforcement', 'selfish genes', and 'intrinsic motivators' change behavior like, well abracadabra.
So, dear reader, I am sure that you personally think that you are quite resistant to this intellectual flimflam. To which I say that you too have a need to believe. So, here's an intellectual trick for you, one that has been foisted upon the most banal and brilliant minds. Indeed, I will even reveal its secret to you, which a magician would only hint, and a con man (or should we say scientist?) conceal or deny.
First, get in a quiet place, and eliminate all intrusive thoughts and distractions. Pronounce the magic word abracadabra, and keep doing so for the next twenty or so minutes. Voila! You will feel relaxed, alert, supercharged! And it's all because you've learned to meditate, or more plainly, elicit a relaxation response. Since repeating a nonsense word seems to be the only independent variable that correlates with these great states of mind, it stands to reason that the magic is all in the word, and that nature had conspired to hard wire a relaxation response to the trivial neural buzz of a thought.
So where you may ask are the hidden variables in a psychological space so hermetically sealed? Why in the quiet of course. Doing nothing and thinking of nothing is an independent variable, since it represents the escape not only of conscious thoughts, but also of the nonconscious arousal or anticipation of imminent things. In a resting state, thinking becomes more acute, our muscles are relaxed, and a magic word is merely a redundant and unnecessary key. Indeed, if abracadabra caused good feelings, it wouldn't matter where you mumbled the words, but common sense reveals that perseveration in thinking doesn't help much when you are in traffic, watching TV, or awaiting the gallows. Magic words you see still need repose to work their magic, but repose only needs itself. But without magic meditation is a non thing, or nothing really. That's the bad thing about behavior when it is made plain. It can't make a living for a magician, and it can't for a psychologist either. So economics if not truth dictates that we will always have magic, and for psychology, the eternal verity of magic words.
For more on the parlor trick of meditation, I have more than a few things to say, as you may find here.