Scientific Theory - Do Plants Feel Pain?

[Raven's Nest]

Sometimes, I think scientists don't understand the limitations of their own field.

Ok, I agree with virtually everything you said up to this point, but how exactly does this statement follow anything you said before or has been discussed in this topic? Why the sudden attack on scientists/scientific procedure? What does it have to do with anything? And on what basis do you make this accusation?

I know my response sounds a little out of proportion, but I am a scientist by training and profession, and accusing scientists, and in particular biologists, in general of having such massive ignorance in their own field of study is one of the most insulting things you could possibly say to me.

I think Crystal Shadow is talking about the clash between subjective evaluations of say a psychogist and the objective measurements of a scientist. It's not that your personal ability to perform and understand the science in your field is in question. More that there exists a limit where one can make objective claims and that scientists are not always capable of proving a subjective hypothesis with objective science and that this is due to a limitation of the current level of scientific knowledge within a specified discipline. A scientist might be unable to accept this limitation to the point where they start to ignore the potential limitations of their field of study, a type of confirmation bias if you will. It does however work both ways. A psychologist will never be able to be 100% sure of their claims whilst the ability to objectively prove them is beyond science's grasp, no matter how many people agree with them, this would be undoubtedly frustrating too. It'd be like being completely convinced you'd seen a ghost but had no way to conclusively prove it.

At least that's how I interpret it...

 

[Thedutchjelle]

Hehe, what a coincidence I'm reading this thread. I have a Neurophysiology/Brain anatomy exam friday :<. I saw another biologist in this thread. Hello!

As stated many times before by other users in this thread, plants lack a nervous system and therefore cannot feel pain. You could try to ask the same for bacteria, virusses, fungi and so on.

 

[CrystalShadow]

Sometimes, I think scientists don't understand the limitations of their own field.

The application of excessive scientific thought has never hindered the understanding of a quandary. After all, it lead to your solution.

That might be true, to an extent, insofar as I'm making statements that are consistent with the spirit of science. But that is not always how science is being used.

Sometimes, I think scientists don't understand the limitations of their own field.

Ok, I agree with virtually everything you said up to this point, but how exactly does this statement follow anything you said before or has been discussed in this topic? Why the sudden attack on scientists/scientific procedure? What does it have to do with anything? And on what basis do you make this accusation?

I know my response sounds a little out of proportion, but I am a scientist by training and profession, and accusing scientists, and in particular biologists, in general of having such massive ignorance in their own field of study is one of the most insulting things you could possibly say to me.

I know it sounds like an insult. And it might be a little mis-directed, in that those who abuse it aren't necessarily scientists. It was probably also an over-reaction on my part to frustration with certain groups of people.

I studied physics for a while. But I certainly don't have a degree.

The reason I say what I do is because I've noticed a tendency amongst some to claim science can answer anything, and within science as an institution, frequent appeals to authority, where claims are supported, or rejected not on their merits, but almost entirely on the credentials of who is involved in either supporting or rejecting a claim.

Dogmatic adherence to science is no better than dogmatic adherence to religion. But religions typically frame their statements in terms of 'divine truth' or some such thing which cannot really be challenged by rational means.

(Richard Dawkins gets on my nerves, to say the least.)

But, I guess that was a rather flippant way of expressing an underlying frustration with certain groups of people that sometimes don't acknowledge, or even recognise the limitations of their own beliefs.

What I was trying to get at was merely that the idea that science, given what it represents, can answer any question that might be posed, and even that the answers it finds to things are in any way representative of the truth of the situation (regardless of how well a theory or model correlates with observation) is not something that should be taken for granted.

And all too often, I come across statements which suggest people have forgotten this. So certain that their own particular theory is some kind of 'truth', and that anything can be explained given enough time, but failing to consider the most basic tenets that underlie how they arrive at these answers to begin with.

To be fair, this wasn't at all meant as an attack on biologists in particular.
And I expressed this in a rather inflammatory way.

It's just very frustrating sometimes to watch people make statements about things as if they have all the answers, when a basic understanding of how they arrived at even the knowledge they do have, suggests that is a rather dubious thing to be claiming.

But you're right. That was not the best way of expressing my frustration.

 

[Mikodite]

Funny there are people going on about how 'subjective' pain is. The problem with that argument is that, as some have assumed incorrectly, pain is not an emotional response, its a sense according to science. You see the five sense model came from Aristotle, and modern science now realizes that its too simple and have added at least five more that humans have. The ability to receive pain is one of them.

Before I go on, I want to remind people of a branch of scientific research known as 'pure science', which is science for science's sake. There might be no applicable purpose for knowing whether or not a plant is capable of sensing pain other than maybe to prove/disprove the theory that you require a central nervous system (or any nervous system) to feel... period, and pain seems to be an easier one to test. All it would be doing is adding to what we know about biology.

Ok. We all know that plants have no brains. They have no nerves, and they have no synapses, and no means to store information. Now, does that mean that they are incapable of feeling... anything... at all, like pain? Seeing if a plant can detect pain is a step in figuring this out. Now, I think they are testing for this by taking a tree, hooking shit up to it, measure for a baseline reading, then presenting it something that would, by our own logic, hurt (like fire or chopping a branch), and check the readings for noticeable changes.

If the readings did change, and that becomes the consensus in repeats, well, that means the tree was reacting to the stimuli. Now, could that reaction, if be it the case, be the tree feeling pain? Remember that theories explain facts, a guess is a hypothesis.

Someone brought up that a tree doesn't need to feel pain because they are stationary and couldn't react in the face of harm if the circumstances brought themselves to that. Well, there are a lot of redundant functions that the human body engages in that are not necessary to survival and yet we waste resources on them anyways.

Course, I'm curious as to what they might find, for better or worse.

 

[emeraldrafael]

I would say they do, but not in the way we do.

They definitely suffer from negative enforcement, but I dont know about if you stepped on one if it would be the same as if I stepped on you.

Of course this is all leading up to the discussion, should plants get the same rights that animals do, and should people who enact "pain" on plants be punished? Cause I'm just waiting for it to get to the point where its a federal crime to cut your grass.

 

[Raven's Nest]

What? The concept of pain isn't exclusive to humans... Ever accidentally trod on a dogs paw? They yelp and might limp afterwards... Definitely a reaction to pain. My ex's mum accidentally burnt her dog with a cigarette once, obviously this hurt the dog and it's been afraid of cigarettes ever since...

OT: last I heard (and I study animal welfare), scientists aren't even sure if fish truly feel pain. I think there's a long way to go if you wanna prove that plants can, with their lack of brain and nervous system and all...

I refer to my post above. We can't communicate on an equal level with animals, and as long as they cannot relate their experience themselves, we are ascribing them feelings based on our own experiences. They are reacting to being exposed to harm, but we interpret their reactions in our idea of how reacting to pain looks like. Maybe that's why scientists are having trouble determining if fish feel pain or not. We can't read their reaction to something that should cause pain in a way that is meaningful to us. The dog reacts in a way similar to humans, but fish can't emote in the same meaningful way for humans as a dog. Of course something happens to a fish if it gets burned by a cigarette, but our concept of pain can't be easily applied to a fish, that's why we can't determine if it feels pain. You can't quantify pain in a meaningful way and apply it universally.

I'm not saying it's ok to harm animals, I'm just trying to put the concept in a context (and get people to stop wasting their time discussing "pain" and "plants" in realtion )

I understand your point and I'm aware of the danger of anthropomorphism when dealing with the subject. I believe however, that since the physiology of mammals are very similar and the level of response to a stimuli which we can reasonably predict, it's likely that mammals feel pain much in the same way we do. Animals have been observed to react to sources of pain so similarly to us, such as memory association and social awareness, it does seem likely that it triggers the same neurological patterns, indicating a similarity of feeling. It'll never be conclusive owing to the language barrier but it certainly seems likely. As long as you define pain in quantifiable terms relating to physical and observable mental responses that is.

I guess it would however, be unfair to call pain in animals a "symptom" of a problem.

 

[Heathrow]

[A greatly reduced number of words.]

You take offense to people and academia, these are not science.

 

[DrOswald]

Sometimes, I think scientists don't understand the limitations of their own field.

Ok, I agree with virtually everything you said up to this point, but how exactly does this statement follow anything you said before or has been discussed in this topic? Why the sudden attack on scientists/scientific procedure? What does it have to do with anything? And on what basis do you make this accusation?

I know my response sounds a little out of proportion, but I am a scientist by training and profession, and accusing scientists, and in particular biologists, in general of having such massive ignorance in their own field of study is one of the most insulting things you could possibly say to me.

I think Crystal Shadow is talking about the clash between subjective evaluations of say a psychogist and the objective measurements of a scientist. It's not that your personal ability to perform and understand the science in your field is in question. More that there exists a limit where one can make objective claims and that scientists are not always capable of proving a subjective hypothesis with objective science and that this is due to the current level of scientific knowledge within a specified discipline. It does howeve work both ways. A psychologist will never be able to be 100% sure of their claims whilst the ability to objectively prove them is beyond science's grasp.

At least that's how I interpret it...

Well, yeah, the inability to prove something with objective measurement and reasoning happens all the time, but that doesn't mean that scientist don't understand this fact. Which is was crystalshadow said. Perhaps he didn't mean that, but it is what he said.

I should apologize for getting so annoyed at what was probably just a grammar error. It is just that this is a bit of sore subject for me. I come from a highly religious community and there is always a small minority of such groups that think science is a tool of the devil and are very loud about it. Claims of scientists as a group are evil/incompetent sometimes get to me.

So, sorry for derailing the thread.

P.S. Psychology is a field of science. It uses qualitative measurement more often than quantitative, but psychologists are no less scientists for that fact.

 

[kortin]

You obviously don't watch the mythbusters *rolls eyes*

 

[CrystalShadow]

[A greatly reduced number of words.]

You take offense to people and academia, these are not science.

scientists aren't science either.
(They're people that make use of science.)

But yeah. That's kind of the whole point of what I was getting at really.

 

[FarleShadow]

You obviously don't watch the mythbusters *rolls eyes*

because if Mythbusters say it, IT MUST BE TRUE! *Massive sarcasm*

Seriously though, Plants can't feel pain, because feeling pain requires both detection of a painful stimulus AND a reaction to it, since plants exhibit neither. (I guess you could technically count Apical dominance as an incredibly crude way of doing it, but that's not the same)

Someone mentioned the Acadia tree, reacting to leaves being eaten by producing tannins and letting other trees know of foragers in the area as if it indicated a pain response system. I would argue that the second part, which causes other trees to start producing tannins could just be a secondary effect of the original evolution. They're just picking up on the signal as it wafts on the breeze and are mistaking it as damage. Unless you're invoking a designer. Then go away.

 

[chunkeymonke]

"Pain" is an abstract social construct relating to human experience and human perception. It makes no sense to try to quantify it and analyze it in a natural-science discourse.

I think your talking about emotional pain
Real pain is very scientific and no way social its your brain sending sharp signals to your nerves to force you to be aware of harm to your body

 

[Raven's Nest]

Well, yeah, the inability to prove something with objective measurement and reasoning happens all the time, but that doesn't mean that scientist don't understand this fact. Which is was crystalshadow said. Perhaps he didn't mean that, but it is what he said.

I should apologize for getting so annoyed at what was probably just a grammar error. It is just that this is a bit of sore subject for me. I come from a highly religious community and there is always a small minority of such groups that think science is a tool of the devil and are very loud about it. Claims of scientists as a group are evil/incompetent sometimes get to me.

So, sorry for derailing the thread.

P.S. Psychology is a field of science. It uses qualitative measurement more often than quantitative, but psychologists are no less scientists for that fact.

Ooh I can barely imagine the frustration of operating as a logical, reasonable scientist whilst surrounded by an ignorant and spiteful community like that. You have my condolences. Here in the UK there is virtually no questioning science as valid so long as it has been reviewed by it's peers.

I know psychology can be pretty scientific when it wants to be but it's a little too inconsistent I find. In fact, the last psychologist I encountered (who was counselling my ex-girlfriend) was so adamant that it was all the mothers fault (can't believe she has come up twice in this thread), that she practically ignored every counterpoint she was told in order to satisfy her own theory... Not very scientific I have to say.

 

[Damien Granz]

Sensing stimuli and feeling a specific emotion or sensory range are not the same thing.

Plants can sense light, and will grow towards light. This does not mean that they have eyes and the ability to see, even though 'sensing light' is about what eyes do. They're similar, but it's not exactly the same.

Similarly, my web camera can be blinded by a bright light in the same way that a human eye might, but not sense pain because it has no way to process the data. A webcamera might 'react' to damaging data (such as bright light), by refocusing its lenses automatically to compensate for flare so that it might better see in bright conditions, but that still doesn't mean that it has the capability to sense pain.

Most animals do have this capability, but plants lack a brain or nervous system capable of interpreting the data.

So unless somebody can prove that whatever rudimentary stimulus response is also capable of collecting and retrieving data in the way that an animal's brain can, then there's no reason to assume they can sense pain.

 

[kortin]

You obviously don't watch the mythbusters *rolls eyes*

because if Mythbusters say it, IT MUST BE TRUE! *Massive sarcasm*

Seriously though, Plants can't feel pain, because feeling pain requires both detection of a painful stimulus AND a reaction to it, since plants exhibit neither. (I guess you could technically count Apical dominance as an incredibly crude way of doing it, but that's not the same)

Someone mentioned the Acadia tree, reacting to leaves being eaten by producing tannins and letting other trees know of foragers in the area as if it indicated a pain response system. I would argue that the second part, which causes other trees to start producing tannins could just be a secondary effect of the original evolution. They're just picking up on the signal as it wafts on the breeze and are mistaking it as damage. Unless you're invoking a designer. Then go away.

So wait, you require your people to be in lab coats? Because someone says it, doesn't make it true at all. The mythbusters could be wrong, anyone could be wrong. I'm sorry, but we have no technology to prove this "theory" or disprove it.

 

[NezumiiroKitsune]

Plant's cannot feel pain. Growing towards more favourable conditions is a tropism. All the answers to your question's are answered in studying tropism's. The experiment with heated grates would be impossible to perform to encompass all plant life; it would depend on the plant's enzyme's optimal temperature, which would vary depending on where the plant is native to.

Pain is a more complex response than tropism's. It's a not fully understood emotional and sensory response, which is why it's debatable that lobsters feel anything when they're thrown into boiling water.

 

[Harry Mason]

"Pain" is specific to the nervous system. Saying that the act of something responding to stimulus is automatically a pain response is preposterous.

Cities respond to stimulus. Everything from natural disasters to changes in economic climate can change the topography, organization and infrastructure of a city, but I'm not going to say that a city expanding around say, a mountain or other development is a "pain" response!

 

[OldGus]

Now take a person who for all intents and purposes is a vegetable. Their nervous system ceases to function, so they cannot have a reactionary response to outside stimuli, even though their immune system will still heal itself. (Or vice versa in some cases). So then would this mean a nervous system is required to feel pain?
-snip-
Let?s talk plants. They have no nervous system, yet they seem to react to stimuli through other methods; http://www.zeenews.com/news641166.html (interesting tidbit on reactions to light, memory and resistance to disease). So they have certain chemical reactions in ways which mimic other life forms in their need for survival and resistance to pain (as defined as physical suffering due to injury or illness).

We also came up with 2 plausible additional experiments to test plant reactions to things deemed ?harmful? to all life. The first was to put a crawling plant (one that grows upward toward light the shortest distance possible) next to two equally spaced and sized grates. One would be super heated to the point of burning anything it touches, the other left at room temperature. We surmised that the plant would choose the less lethal path when growing. The 2nd experiment was to put 2 plants in 2 separate sound proof rooms. The first would receive 30 decibels (whispering) of music while the other would receive 115 decibels (rock concert). We surmised that the 115 decibel plant would wither and die sooner than the 30 decibel plant (as studies have already indicated various sounds affect plants). It became obvious with every experiment (that didn?t involve killing the plant strait away), that plants reacted in the same way other life forms do to damages.

So then we went back to ?feeling? pain. Since ?feel? is defined as a perception or sensation to something, the chemical reaction seemed to suffice in saying; ?since plants chemically react to damaging stimuli through some sensory methods (even if not quite fully understood), then plants must feel pain?. Am I personally convinced? Not entirely, although scientifically speaking, the statement has merits.
-snippity-

An expansion to determine the feeling of pain would be to find, document, and determine how and why exactly a plant reacts to something that is not either helpful or detrimental to it. The sound part gets close, but consider that sound at high enough volumes does damage people regardless of if they can hear it or not. It must be assumed then that sound does have some biological effect on living organisms as it clearly has a biological effect even on organisms that can't hear it (super-low frequency sound waves at 115 decibels or higher can still affect humans.) What might be better with a sound experiment is to see if plants have taste in music, so to speak. In other words, keep the decibels the same, but play two or more different types of sound: yelling, polite conversation, classical music, techno, maybe even a jet engine versus a V8. A response in this test would show that a plant has a reaction to a stimulus that is not based purely on survival (consider that not all taste or pain responses with humans are based on survival. In fact, for many people there are things that "taste bad" but are still nutritionally vital.)
Now, consider another side to try and carry over-- for an example with humans, electricity and capsaicin. Both in low doses do not affect health, but do produce a pain response. Admittedly with electricity, that is because it directly stimulates the nervous system by forcing an electrochemical response. The test for this would be simple... find something that the plants react to by trying to avoid contact with, but at the same time, prolonged exposure at the same levels produces no visible negative effects. In other words, a plant that successfully avoids exposure is similarly or nearly as healthy as a plant that doesn't avoid exposure.
Now, as far as the implications of such a study, I would hope it would point out to anyone paying attention that yes, we do need to respect what we eat. Period. Then, I hope that people would make the logical conclusion that if you respect what you eat, which in either case includes sustainability such that you don't just eat what you like til it's gone, then its ok to eat that, regardless of if it is a plant or animal.


Now, off topic a bit... and this is really off topic enough that I'm just gonna do this...

Spoiler

I understand going vegan for health reasons (such as a protein allergy-- yes, they do exist), but I do take issue with vegans who say their choice not to eat dairy or eggs is because it is harmful to the animals. I call bull. We're talking the equivalent of chicken periods and mammalian wet-nurse-ery. Anyone who knows anything about "where your food comes from" 101 knows that A: eggs have to be tested to see if they were fertilized, because not many people like a chicken fetus (no, not all eggs are chicken fetuses, get over your ignorance if you really think this) in their omelet, and B: If Bessie don't get milked at her usual time, well, she tends to complain more than if she is milked. So, unless those same people are willing to hold half-funerals for every period a woman has and to openly condemn the practice of wet-nursing infants, then they really don't have a leg to stand on in my book.

 

[OldGus]

Someone brought up that a tree doesn't need to feel pain because they are stationary and couldn't react in the face of harm if the circumstances brought themselves to that. Well, there are a lot of redundant functions that the human body engages in that are not necessary to survival and yet we waste resources on them anyways.

Something else to bring up on this point... trees may not be able to move, but they are able to make themselves more poisonous (since the usual threat to trees is being eaten). furthermore, they can release clouds of chemical messengers warning surrounding trees that a leaf-eater is in the area, prompting them to up the tanin levels in their leaves.

 

[CrystalShadow]

Funny there are people going on about how 'subjective' pain is. The problem with that argument is that, as some have assumed incorrectly, pain is not an emotional response, its a sense according to science. You see the five sense model came from Aristotle, and modern science now realizes that its too simple and have added at least five more that humans have. The ability to receive pain is one of them.

Before I go on, I want to remind people of a branch of scientific research known as 'pure science', which is science for science's sake. There might be no applicable purpose for knowing whether or not a plant is capable of sensing pain other than maybe to prove/disprove the theory that you require a central nervous system (or any nervous system) to feel... period, and pain seems to be an easier one to test. All it would be doing is adding to what we know about biology.

Ok. We all know that plants have no brains. They have no nerves, and they have no synapses, and no means to store information. Now, does that mean that they are incapable of feeling... anything... at all, like pain? Seeing if a plant can detect pain is a step in figuring this out. Now, I think they are testing for this by taking a tree, hooking shit up to it, measure for a baseline reading, then presenting it something that would, by our own logic, hurt (like fire or chopping a branch), and check the readings for noticeable changes.

If the readings did change, and that becomes the consensus in repeats, well, that means the tree was reacting to the stimuli. Now, could that reaction, if be it the case, be the tree feeling pain? Remember that theories explain facts, a guess is a hypothesis.

Someone brought up that a tree doesn't need to feel pain because they are stationary and couldn't react in the face of harm if the circumstances brought themselves to that. Well, there are a lot of redundant functions that the human body engages in that are not necessary to survival and yet we waste resources on them anyways.

Course, I'm curious as to what they might find, for better or worse.

That doesn't really help much. The experience of pain is subjective irrespective of if it can be considered a sense or not.

I can certainly make measurements about my response to blue light; What frequency is it that I perceive as blue? Is this the same frequency that another person would call blue?
How does my brain process the information coming into my eyes?

Even the algorithms involved, information about how the visual input is used, and so on...
We could determine and measure all of this, and still not be able to answer the basic question:

What is it like to see the colour blue?
Is your experience of something blue the same as mine, or totally different?

That's what's subjective here. Not the processes.

We could know everything there is to know about how neurons work, what kind of electrical signals correspond to pain, and so on, and still not know what it's like to experience it.

And since the experience of pain is what separates, say, a robot that has some kind of damage reporting mechanism, and routines to reduce it damaging itself,
And a living being that feels pain, and suffers mentally because of it...

But, since it's already clear that what we can measure about pain in humans relates to having a central nervous system, it's difficult to see how you could determine if there's anything similar going on in plants that could legitimately be called 'pain'.