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Sickness behaviour – useful concept or psycho-humbug?

Discussion in 'General ME/CFS News' started by Woolie, Nov 22, 2017.

  1. Valentijn

    Valentijn Moderator Staff Member

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    But hunger is a biological state. It's a "feeling" in that it's perceived, not in that it's an emotion.
     
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  2. Hip

    Hip Established Member (Voting Rights)

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    Agreed, but this biological state causes effects in the brain and mind, which in turn modifies behavior.

    Surely the idea of biological factors modifying behavior is a pretty straightforward one.
     
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  3. Valentijn

    Valentijn Moderator Staff Member

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    Yes, but it is ultimately the biology driving the behavior. Any mental aspect is so trivial and automatic as to be inconsequential except in the case of illness (anorexia). It isn't the mental state which modifies behavior - it's the biological need for fuel and the biological drive to fill that need.
     
  4. Hip

    Hip Established Member (Voting Rights)

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    Myself, I would say it is the mental state which actually carries out the modification in behavior. Although hunger is underpinned by a biological process which affects the brain, I think it's only when that effect on the brain enters into your mental awareness (either consciously or unconsciously — because we can also be unconsciously aware of many things) that behavior can be modified.

    As my working definition, the mind corresponds to (and integrates) the areas of the brain that we can become consciously aware of. For example, if you have an itch or pain in your foot, that info is transmitted to the brain, and then as the next step, enters into conscious or unconscious awareness (your mind). You may as a result, either consciously or unconsciously, scratch your foot.

    Thus if any of areas of the brain that we can become consciously aware of are altered by some physical biological process such as a hunger hormone, then it will in turn enter the mind. But if a biological process alters some part of the brain that we can never become consciously aware of, then it will never enter the mind.

    An example of a biological process affects the brain, but does not enter into the mind is the control of blood pressure by the medulla oblongata in the brainstem. This part of the brain receives information about the current blood pressure level from various baroreceptors in the body, and then in response sends outputs to the body in order to control and maintain blood pressure. But we are entirely unaware of this biological process in the brain, because although it enters the brain, it never enters into the mind. Thus not everything that enters the brain enters the mind.

    So generally speaking, I think a biological process that affects the brain can only modify behavior if it enters the mind (by which I mean it enters into conscious or unconscious awareness).

    The only counter-example I can think of, where a biological process affects the brain, and may alter behavior without entering the mind, is pheromones (pheromones are chemicals in the air which we can detect with a special organ, but which we are not aware of).
     
    Last edited: Nov 26, 2017
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  5. Barry

    Barry Senior Member (Voting Rights)

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    I just have a real problem with any statement that evolution purposefully designs anything, be it a turn of phrase or otherwise.
    To me the feeling of hunger is a symptom of the body needing more fuel, provoking the behaviour of eating. Fear is a symptom of being confronted by danger, provoking various danger-handling behaviours. Falling in love is probably a bit more complex, :), but probably does still come down to a whole raft of 'symptoms', provoking an even greater range of behavioural responses ... :):).
     
  6. Valentijn

    Valentijn Moderator Staff Member

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    Yet single-celled organisms and many multi-cellular organisms without a brain need nutrition, and will alter behavior to get it. Since they manage to feed themselves and survive without a brain, it would seem that a brain is not particularly necessary to respond to hunger, except to the extent it's needed to coordinate a more complicated physical reaction.
     
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  7. chrisb

    chrisb Senior Member (Voting Rights)

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    We will soon be getting on to the fascinating subject of spandrels.
     
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  8. Barry

    Barry Senior Member (Voting Rights)

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    Seems we just have :).
     
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  9. Inara

    Inara Senior Member (Voting Rights)

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    What's a spandrel? Only get a translation that doesn't make sense (sorry for spoiling your joke).
     
  10. Hip

    Hip Established Member (Voting Rights)

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    Sure, but such simple organisms have a very much reduced repertoire of behavioral responses compared to higher animals, and many behavioral responses of simple organisms are no more complex that say the mechanical response of a thermostat. Whereas the behavioral repertoire of higher animals is far richer and infinitely more complex, not to mention highly adaptive and creative, and thus it may require the power of consciousness to run all this incredibly complex behavioral action.



    Maybe purposeful is not quite the right word, but there are intelligent processes and intelligent choices going on in evolution.

    Intelligent choices are intrinsic to sexual selection. When people think of Darwinian evolution, they usually think of natural selection (survival of the fittest). But in the Origin of Species, Darwin proposed two mechanisms of evolution: natural selection and sexual selection.

    Sexual selection brings intelligence into evolution. For example, if you choose your spouse, your reproductive mate, on the basis of having the quality of being good breadwinner, it is your intelligent choice that will promote their genes into the next generation.
     
    Last edited: Nov 26, 2017
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  11. chrisb

    chrisb Senior Member (Voting Rights)

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    I had rather hoped that we might have someone here better qualified to comment. It is an idea in evolutionary biology created by Gould and Lewontin. A spandrel was originally an architectural term for part of an arch which is not structurally significant and which is available for ornamentation.

    The idea, as I understand it, is that whilst nature is selecting for certain characteristics, there may come along with those other inessential characteristics for which a use is found. Not all characteristics are therefor adaptive. Some may be almost coincidental.
    The most primitive animals are capable of feeding themselves. It may be that we do not need "hunger" to survive.

    I recommend that reference is made to a better source.
     
  12. Inara

    Inara Senior Member (Voting Rights)

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    Thanks, @chrisb, I already looked online and understood the idea. Your reference to Gould and Lewontin helped hereby.
     
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  13. Scarecrow

    Scarecrow Senior Member (Voting Rights)

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    Sexual selection refers to the selection of characteristics that don't directly enhance survival but lead to greater mating success, e.g. the croak of a male frog won't help to evade predators or find food but it will attract females. There's nothing intrinsically intelligent about it. It's really just a special type of natural selection.
     
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  14. Mij

    Mij Senior Member (Voting Rights)

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    I hope this isn't too off topic, but found it quite interesting.

    https://www.sciencedaily.com/releases/2017/09/170921141252.htm

    "At first glance, humans seem to have very little in common with Cassiopea, a primitive jellyfish. Cassiopea is brainless, spineless, and spends essentially its entire life sitting upside down on the ocean floor, pulsating every few seconds. However, Caltech scientists have now discovered that, as different as our daily schedules may seem, humans and jellyfish actually start and end their days with the same behavior: sleep. This finding that jellyfish sleep implies that sleep is an ancient behavior, largely untouched by millennia of evolution".
     
  15. Hip

    Hip Established Member (Voting Rights)

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    My understanding is that sexual selection will tend to choose characteristics that demonstrate the health, fitness or capabilities of the animal. The classic example is the plumage of a peacock: a healthy plumage indicates a healthy peacock. So here sexual selection of a lustrous plumage is a form of quality control.

    In the human world, for some people, an expensive car may indicate their prospective partner's financial health and breadwinning abilities. So that may play the role of a shiny plumage.

    I guess though in animals such as peacocks, their predilection for a healthy plumage may be more of a hardwired intelligent response than a thoughtful one. But in humans, sexual selection almost certainly involves complex intelligent thought. Whether such complex thought might also be present in the sexual selection process of the more intelligent animals is a matter for debate, but I would guess that the smarter animals may be well be fairly astute when it comes to choosing a reproductive partner.
     
  16. Inara

    Inara Senior Member (Voting Rights)

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    I have to admit that doesn't hold for me. But it worked someday, so... :)

    Honestly, I would doubt that's true for all cases. But I may misunderstand you - if I read "complex intelligent thought" I imagine myself sitting around, pondering about the pros and cons about a man. If I fell in love, I didn't know why, I just had a crush. True, someday I thought about whether it would be smart to succumb. At the same time I think that there are people who don't select due to a feeling, but due to "facts" like looks, status, money and so on.

    Personally, I think that this 'sexual choice' is well-thought by nature; it finds a good gene match, I'd say. And this doesn't happen consciously.
     
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  17. Scarecrow

    Scarecrow Senior Member (Voting Rights)

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    Yes, the theory goes that it indicates that the male is showing good health by being able to display such extravagant plumage, which is energetically costly and makes him conspicuous to predators.

    But if evolution was really intelligent, females wouldn't bother with all that show, they'd just choose really fit but plain males. Then their immediate offspring would be more likely to survive because they would be less conspicuous to predators. Unfortunately, other females wouldn't want to mate with their drab sons. So male peacocks end up looking ridiculous or magnificent depending on the beholder's point of view.
     
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  18. Barry

    Barry Senior Member (Voting Rights)

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    Yes. The point about natural selection is the survival of species, not individuals within that species. Obviously the two often align, though not always. Greater mating success does not improve the chances of the individual's survival, but does for the species. Indeed for the male Black Widow it can seriously reduce his chances, but overall the species' survival benefits from the procreation effort.
     
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  19. Hip

    Hip Established Member (Voting Rights)

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    I would also like to think that I would be more guided by the intuitive chemistry of falling in love, rather than by the various material and non-material benefits a prospective partner might bring into my life. However, I wonder if even in the most "pure" and romantically inclined individuals, there may still be an unconscious and intuitive appraisal of their prospective partner's social and professional standing, and that a positive appraisal of their qualities may actually fuel the emotion of love.
     
    Last edited: Nov 26, 2017
  20. Hip

    Hip Established Member (Voting Rights)

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    But how would the females know which peacocks are fit and healthy, unless they have some way of gauging that? The peacock's plumage provides a gauge of heath, so that makes it useful. But agreed that it is a bit of clumsy and energetically expensive way of sending a signal of health. Maybe there are better signals used in other animal species.

    I saw this amazing documentary about bowerbirds recently, which decorate their nest with any type of blue item, in order to impress the female. See some bowerbird nest pictures here. Hard to figure out how such a practice started, but one might speculate it could be a measure of eyesight acuity or mental determination (since blue items are rare in the natural environment, and thus hard to find).
     
    Last edited: Nov 26, 2017
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