Deterministic thinking meets the fallacy of the one-sided bet

Kevin Lewis asked me what I thought of this news article:

Could walking barefoot on grass improve your health? Some science suggests it can. . . .

The idea behind grounding, also called earthing, is humans evolved in direct contact with the Earth’s subtle electric charge, but have lost that sustained connection thanks to inventions such as buildings, furniture and shoes with insulated synthetic soles.

Advocates of grounding say this disconnect might be contributing to the chronic diseases that are particularly prevalent in industrialized societies. There is actually some science behind this. Research has shown barefoot contact with the earth can produce nearly instant changes in a variety of physiological measures, helping improve sleep, reduce pain, decrease muscle tension and lower stress. . . .

One reason direct physical contact with the ground might have beneficial physiological effects is the earth’s surface has a negative charge and is constantly generating electrons that could neutralize free radicals, acting as antioxidants. . . .

Research also suggests physical contact with the Earth’s surface can help regulate our autonomic nervous system . . .

While many clinical studies have demonstrated beneficial physical changes when participants are grounded, studies tend to be small and are done indoors using wires that connect to ground outlets. . . . Still, since being outdoors is proved to be good for you, it probably would not hurt to try it yourself to see if you notice any benefits. So how do you ground? Simply allow your skin to be in contact with any natural conductors of the earth’s electricity, working up to at least 30 minutes at a time (unfortunately, studies do not seem to have addressed how often grounding should occur). . . .

Vagal tone is often assessed by measuring the variation in your heart rate when you breathe in and out, and in one study, grounding was shown to improve heart rate variability and thus vagal tone in preterm infants. In another small study of adults, one two-hour session of grounding reduced inflammation and improved blood flow. . . .

If you have concerns about whether it is sanitary to walk barefoot outside, there are options. Keep a patch of lawn off-limits to your dog. Or put a blanket or towel between your skin and the ground; natural fibers such as cotton and wool do not interfere with grounding. You can even wear leather-soled shoes. . . .

Leather-soled shoes, huh? But no socks, I guess. Unless the socks are made of cotton or wool or, ummm, leather, I guess that would work? Seems like some magical thinking is going on here.

My response is, as always, that these things could help for some people and situations and be counterproductive at other times. I don’t think the deterministic framing is helpful.

Also, there seems to be some admirable skepticism in the following quote:

If you do notice you are more relaxed, or you are sleeping better, or you have less pain or fatigue – is it the grounding or a placebo effect?

But here they’re making the fallacy of the one-sided bet, by implicitly assuming that the effects can only be positive. If grounding has real physical effects, then I doubt they’d always be positive.

P.S. I see lots of silly science stuff every day, including ridiculous claims, not at all supported by data (just a lot of studies with N=40, p=0.04, and more forking paths than a . . . ummm, I dunno what). Just today I came across a published paper that included a pilot study. Fine . . . but don’t’ja know it, they found statistical significance there too and made some general claims. Which is not what a pilot study is for. (But now surprise they found some p-values below 0.05, given the flexibility they had in what to look for.) Anyway, we see this All. The. Time. Even in prestigious journals. I usually don’t bother posting on these bits of routine cargo cult science. When posting, the idea is to make some more general point. As above.

33 thoughts on “Deterministic thinking meets the fallacy of the one-sided bet

  1. We already knew that walking barefoot was relaxing—we learned that from Die Hard! The interesting thing is that it worked even in a highrise, suggesting it is the freedom of the feet and toes that matters, not “grounding” per se.

    Of course, we would have to include on our Informed Consent document that a potential risk from barefoot therapy is that you may have to run across a room full of broken glass if the building gets attacked by international terrorists.

    Also, speaking as someone who goes barefoot a lot both outside and around the house, I can say that while I find it personally relaxing, my husband thinks it’s gross, suggesting it’s a zero-sum game.

  2. What makes this deterministic thinking? Something like this having a mix of good and bad effects just implies interactions. “Determinism” doesn’t seem like the best word for the failure to consider interactions/complexity, ja?

  3. I think the true causal pathway, if there is any, between walking barefoot and improved health is through improved posture, proprioception, and correct movement patterns in legs/hips/back. Show me the DAG!

  4. > Leather-soled shoes, huh? But no socks, I guess. Unless the socks are made of cotton or wool or, ummm, leather, I guess that would work? Seems like some magical thinking is going on here.

    If there is magical thinking going on it’s on the broad “touch the ground” thing, not on the leather-soled shoes bit in particular. Don’t you agree that they will be more conductive than rubber-soled shoes? (On the other hand, the “natural fibers such as cotton and wool do not interfere with grounding” is a bit misleading, the conductivity of those fabrics depends on the humidity and I think if they’re dry they are quite good insulators.)

  5. > So how do you ground? Simply allow your skin to be in contact with any natural conductors of the earth’s electricity

    What about “artificial” conductors of the earth’s electricity? Taking a bath could be enough unless you have PVC plumbing.

  6. “The idea behind grounding, also called earthing, is humans evolved in direct contact with the Earth’s subtle electric charge, but have lost that sustained connection thanks to inventions such as buildings, furniture and shoes with insulated synthetic soles.”

    I love this example of the use of evolution to push the naturalistic fallacy to the limit. We also evolved in an environment where large predators ate humans. Maybe that has a health benefit. We should release a pack of man-eating lions on the West Side of NYC and see what happens.

  7. The TED Talk, the book:

    Grounded: How Going Barefoot (Literally and Figuratively) Transforms Your Health and Life

    And the back-cover summary refers to “groundbreaking research.”

    Which makes me wonder whether the bestseller/”big fix” industry has a few cynical editors cackling in the back rooms.

    • Thank you Andrew for the link to the compendium of statistical fallacies, trips and sorceries.
      Very useful and entertaining.

      Sorry for going off piste. That page also led me to discover a paper with really low probabilities. (~10^-85!!).
      http://www.stat.columbia.edu/~gelman/research/published/probdecisive2.pdf
      A fun read.

      This bit makes me rethink expected payouts for targeted small scale voter fraud:
      “We can also consider the incentives for campaigns and voter organizers. We estimate that turning out 1,000 additional voters for your side (or persuading 500 people to change their vote) in New Mexico would have a 1.3% chance of flipping the state in the event (with probability 1.2%) that its electoral votes are
      equivalent to a charitable contribution. Fowler (2006) gives experimental evidence relating altruism to voter turnout.
      decisive, which combine to a 1 in 6,000 chance of swinging the national election. The same effect could be attained at the national level by persuading 10,000 random supporters to vote or by persuading 5,000 random supporters of the other side to switch.”

      • Yes, probabilities of 10^-85 or even lower are easy to obtain. For example, consider the probability of going to a roulette table in Vegas and rolling 00 a hundred times straight. I have no problem with probabilities of 10^-150 or whatever. What I have problems with is people using a low p-value to reject straw-man null hypothesis A and use that as evidence in favor of a preferred alternative hypothesis B.

        Regarding your last point: If a political organization has no scruples and no risk of getting caught, they might as well do all sorts of fraud, large and small, wherever they can. The choice of whether to do fraud and, if so, how much, is determined by the tradeoff between expected election wins, on one hand, and scruples and fear of getting caught, on the other. But, yeah, the probability of a vote being decisive, or of 1000 votes being decisive, is not such a difficult calculation, once you frame it correctly.

  8. Isn’t there some linguistic confusion here about grounding? People who work with sensitive electronic equipment ground themselves without going outside or connecting to plumbing. They don’t risk getting hookworm, either.

        • Ground is ground. You may reduce problems with static by touching random things but that’s not the same as grounding. A proper ESD workstation will have everything connected to a common point ground.

        • That’s my point. Electrical grounding is not the same as earthing. But the quoted discussion confuses the two.

          BTW, for grounding our houses we ultimately have Benjamin Franklin to thank. Lightning rods are grounding rods.

        • What is electrical grounding then, if it’s not connecting to the AC ground (or maybe an auxiliary ground) which is connected to the actual earth?

        • Electrical grounding does not require connection to the earth. “Grounding is the process of removing the excess charge on an object by means of the transfer of electrons between it and another object of substantial size.” (https://www.physicsclassroom.com/class/estatics/Lesson-2/Grounding-the-Removal-of-a-Charge)

          I was unaware that earthing is also used to refer to electrical grounding. My mistake. I used it to refer to the general idea the article is about.

          —-

          By contrast, the article states: “One reason direct physical contact with the ground might have beneficial physiological effects is the earth’s surface has a negative charge and is constantly generating electrons that could neutralize free radicals, acting as antioxidants. You may think of antioxidants as coming from food. . . . Still, it is interesting that we may be able to get them directly from the earth, too.”

          That, OC, is idiotic. By what means do electrons that contact your skin enter all the cells of your body? I doubt if eating dirt will help, either. Besides, in electrical terms grounding neutralizes the body’s electrical charge. There are no excess electrons to interact with free radicals within cells.

          The article also states: “While many clinical studies have demonstrated beneficial physical changes when participants are grounded, studies tend to be small and are done indoors using wires that connect to ground outlets.” This experimental setup obviously relies upon the idea of electrical grounding as a way of coming in contact with the earth. Why not also include an experimental condition where the wires connect to a large metal plate or something? That would provide electrical grounding without connection to the earth. That matters because the theory is that not coming into contact with the earth is problematic. But if discharging static electricity is the answer, well, we do that all the time, right? The mystique is gone.

          The article continues: “So how do you ground? Simply allow your skin to be in contact with any natural conductors of the earth’s electricity, working up to at least 30 minutes at a time (unfortunately, studies do not seem to have addressed how often grounding should occur).”

          This again is idiotic. As anyone who has gotten a shock from a doorknob knows, electrical discharge (grounding) is instantaneous. 30 minutes? Sitting or walking in a park for 30 minutes may well be beneficial, but not because of electrical grounding.

        • That’s a very strange definition, to say the least.

          http://file.yizimg.com/110970/20161212-174038618.pdf

          ANSI/ESD (Electrostatic Discharge Association) S6.1-2005

          Standard for the Protection of Electrostatic Discharge Susceptible Items

          Grounding

          “The single most important concept in the field of static control is grounding. Attaching all electrically conductive and dissipative items in the workplace to ground allows built-up electrostatic charges to equalize with ground potential. A grounded conductor cannot hold a static charge.

          “Electrically interconnecting all electrically conductive and dissipative items (bonding) allows charge to equalize across these items without actual contact to ground. This provides static control in areas where ground may not be accessible, such as in a field service environment. (…)

          “5.1 ESD Grounding/Bonding Reference Point

          “The application and the physical environment will dictate the choice of the actual grounding system that will provide the best overall ESD protective system. The user of this document must select from the following systems in order to establish the ESD grounding /bonding reference point (see paragraph 5.1.1, 5.1.2, and 5.1.3).

          “5.1.1 AC Equipment Ground
          Within an EPA, the AC equipment ground is the preferred ground when available. The equipment grounding conductor electrically bonds the AC equipment ground to the ground bus at the main service equipment panel of the facility. AC equipment within the EPA and all of the ESD technical elements will be at or near the same electrical potential when this system is used. See Figure 1, Figure 1A, Figure 5 and Figure 6.

          “5.1.2 Auxiliary Ground
          Some facilities require the use of a separate or supplemental ground system. When this is the case, the auxiliary ground shall be bonded to the AC equipment ground when possible. In the event that it is not possible to electrically bond the two ground systems, it should be noted that AC equipment and the ESD technical elements might be at significantly different electrical potentials. See Figure 2.

          “5.1.3 Equipotential Bonding
          Electrically interconnecting all of the ESD technical elements, the personnel within the work area, and the equipment under service, equalizes electrical charges between the items to allow safe handling of ESD susceptible items. See Figure 3.”

    • “A link between atherosclerosis and helminth infections has never been examined. Based on the present knowledge of immune and infectious mechanisms related to atherosclerosis, it is proposed that chronic helminthic infections can have a significant bearing on the epidemiology of cardiovascular diseases.”

      https://www.researchgate.net/publication/7955564_Can_worms_defend_our_hearts_Chronic_helminthic_infections_may_attenuate_the_development_of_cardiovascular_diseases

      Even when it was the grounding, I knew it was the worms.

  9. Strange definition? It’s basic physics.

    Besides, your quoted material agrees that grounding does not require actual connection to the earth.

    ““Electrically interconnecting all electrically conductive and dissipative items (bonding) allows charge to equalize across these items without actual contact to ground.”

    • Note that they call that bonding, not grounding.

      But, hey, you may define things as you want.

      Why would anyone expect “grounding” to have anything to do with a connection to the “ground”, anyway…

  10. A question of perspective. By normal standards this study is not convincing and rightly so in my opinion. Why? Science says rules are true everywhere and everytime but of course that is not so.All theories are false but some are useful is a good truism. In applied knowledge ( tech/eng’g) for something to be true many conditions (steps) must be met very precisely which makes the realization possible only under very narrow conditions.
    So this study claims some generality and fails. Is it possible that there could be very specific and narrow situation where the claim is possible? Yes, possible but very unlikely to be discovered, so not really useful.

    From personal experience I can say that human bodies can interact/affect charge distribution and if observes may be useful in guiding decisions re health choices. Charge and energy interaction remains a deep mystery not really demistified since Rutherford and Planck 100 years ago. My guess is that most will consider the claim from personal experience and will reject it. Not wrong in a practical sense.

  11. Could walking barefoot on grass improve your health?
    Only if you apply enough snake oil.

    Seriously, what does ‘improve’ even mean? I could try to measure it in million different ways, a fail miserably. To be honest, nutrition ‘science’ and similar fields suffer from the same problem. Their dependent variables are dime a dozen and there is synergistic effect impossible to untangle to even begin to talk about the main cause.

    There is no evidence for the harmful effects of PM2.5, EMF/cell phone radiation, etc. either, but for some of those things it might be wise to err on the side of caution. Kinda hard to ‘un-microwave’ a piece of meat once it’s done.

    Grounding sounds like a good idea for posture/stability, if nothing else. Just don’t step on a rusty nail (or a hypodermic needle here in CA).

  12. There is a real physical effect of grounding, insofar s walking barefoot in many parts of Australia is giving extra access to animals that will attempt to kill you if you step on them.

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