It turns out that for most people, the default intention of “holding your arm straight” by tensing your muscles and resisting your partner is not very effective.
Notice the presupposition that "tensing your muscles" is the default way most that most people hold their arm straight? Notice how in the video you linked he explicitly specified "really tight" and didn't just say "don't let me bend your arm", letting people do what actually comes by default? They seem to always specify to make the arm tense, which is unsurprising because if you're not told to resist wrong, you might not resist wrong and then their trick won't work.
I tried it with my wife, only instead of saying "Hold your arm really tight" I just said "Don't let me bend your arm". As a result, she didn't foolishly contract her bicep to help me, and was able to resist just as well as when I told her to visualize stuff. It's not that visualizing firehoses is unusually effective, it's that you're getting bamboozled into doing it unusually ineffectively to start with.
But from what little bit of BJJ rolling I've done, my impression is yes, folk who don't know the unbendable arm trick end up struggling sometimes in ways they don't have to.
I should clarify what would actually surprise me.
Most people at a jiu jitsu gym don't really get jiu jitsu, and struggle in ways that they don't have to if they were to just learn jiu jitsu. This is unavoidable, as learning to jiu jitsu takes time, but it also means that even if BJJ has an equivalent concept of this Unbending Arm thing you should expect these results. I don't doubt that... (read more)
In Materialist Conceptions of God, I wrote about how one can interpret religious claims as hyperstititions, beliefs that become true as a result of you believing in them. Since then, I’ve stumbled on a very simple, practical example of a hyperstition that you can test out in two minutes with a willing partner. It’s the Aikido exercise Unbendable Arm (link goes to a 1 min video).
The goal of the exercise is to hold one of your arms straight while your partner attempts to bend it at the elbow. It turns out that for most people, the default intention of “holding your arm straight” by tensing your muscles and resisting your partner is not very effective. What works much better is consciously relaxing your arm while imagining a situation in which your arm happens to be extremely strong and straight through no intervention of your own. The suggestion in the video is to imagine that your arm is a firehose spewing water at a fire; the way it was first taught to me, I had to imagine my arm extending as a horizontal beam of golden light into the nearest wall and past it into the infinite horizon.
I highly recommend trying this exercise with a partner and noticing what you observe. The two things I noticed were
What is the epistemic status of “imagine an infinite beam of light”? It’s not a propositional claim, I’m not asserting that the beam of light actually exists or is actually infinite. But it certainly seems like the kind of mental operation I’d like to have access to. And if I stick purely to a pure scientific materialist understanding of the world, where anything I believe has to be intersubjectively verifiable, I’d simply lose access to this ability my body has, and be weaker as a result.
If I can make my arm stronger simply by holding holding a beam of light in my imagination, how much can a group of people accomplish if they hold a concept like “the kingdom of heaven” in their collective imaginations? Especially if they build magnificent cathedrals and paint beautiful paintings and write soul-shattering music as visualization aids? We don’t have to guess - we live in the world those people built!
Is the kingdom of heaven actually going to be as perfect as Christians imagine it? Is the lion really going to lie down with lamb? Is God really all-loving and omnipotent? Is that beam of light really infinite? That’s not really the point. Sometimes what’s important about a visualization is what it doesn’t include, what thought processes it forestalls or short-circuits. The beam of light probably needs to be infinite so my attention doesn’t latch onto its endpoint. God has to be all-loving so my attention doesn’t latch onto some bad thing that happened or could happen, distracting me from loving the people around me. In fact the most common use of the word “God” in common parlance seems to be as a stop-token, with a pragmatic meaning along the lines of “stop thinking propositionally / using your left brain / using near mode for a moment”. The clearest example is “Inshallah” - literally “if God wills it” - a verbal formula used to short-circuit worrying about things one can’t control.
Of course, there’s a huge gap between a visualization like Unbendable Arm, which you can toggle on and off in seconds, and a religious conviction like belief in the Resurrection, which many people hold to so strongly they are willing to die for it. I expect most religious people will say these are totally distinct and incomparable phenomena. And there is is certainly a distinction in kind, not merely in scale, which I’m still developing an understanding of. And yet… from where I’m standing, they feel like they share an essential nature - the nature of hyperstition, of using imagination to guide our predictive-processing-powered minds towards our goals.
P.S: If you do end up trying Unbendable Arm with a friend, I’d appreciate you leaving a comment or DMing me with your observations! even a simple “tried it, didn’t work for me” null result is helpful.