A Cognitive Perspective On Plant Pain

Why does pain exist?

As a vegan, I sometimes hear people bring up that food requires other organisms to die. Worse, I sometimes get the proposal that plants suffer too, despite that this is a really massive jump to a conclusion. The idea isn’t one that I totally reject with closed-mindedness, though the nuances to this topic are really important. This post will be an exploration of why pain exists and whether or not plants, insects, or other animals experience such feelings. Whether or not you believe in plant pain, you might find the reasoning about why we feel pain interesting.

Pain seems to play a role in strongly arousing our attention, like a spotlight. Think back to a time you were minding your business and then were suddenly confronted with agonizing pain. This likely caused you to suddenly lose reception of your current task and a sudden flood of awareness on the painful situation.

How might this be adaptive?

You are constantly assessing the importance of various goals you have by weighing them against each other. Some of these goals may be the urge to eat, the urge to use the restroom, the urge to finish your homework assignments or get ahead at your job, and the urge to address pain. The way we experience pain seems to have layers, where one of these layers is something we can call valence. This term valence is the feeling of good or bad, pleasure or suffering. The way we seem to calculate what is most important for us to attend to is through a valence system. This is useful because the urge to eat, the urge to use the bathroom, and the urge to address pain all seem to be very qualitatively different problems and valence is the tool that allows us to generalize some sense of importance to these disparate problems.

When we experience pain, there is a sudden strong increase in negative valence, which causes us to desperately seek relief. This can often rapidly become our most important problem to attend to, thus we lose attention for whatever else we were observing and attend to the pain to attempt to resolve it. This is adaptive because addressing pain is often about addressing our survival or health. Rather than our body expecting us to rationally assess bodily damages, we have this instinct that we call pain. Pain does not require any rational assessment, it is simply a sudden urgency to negative valence.

Why do we feel these things at all?

It seems that we experience these seemingly conscious sensations is so that we can factor them in our complex decision making. We make decisions that deal with widely differing behaviors and responses and we compare our goals with each other to calculate which are the most important to address first. This is because we cannot solve all of our problems simultaneously. We cannot easily use the restroom, while eating, while doing work, while addressing pain, while etc. We often have to make choices because we only have so many arms and only so much capacity to act simultaneously. This lack of a capacity for simultaneous action may have led to the evolution of decision making processes using the brain. The way we experience valence helps identify the degree of importance that each decision has.

There are also many things about our body that we do not decide on. For example, we do not consciously make decisions about our heart rate, our blood flow, our cellular responses to immune threats, and many other seemingly automatic and reflexive processes. These are things that were able to be automated by our body.

Consider what cannot or seemingly simply does not get automated in our body. Our walking seems to be mostly a conscious effort. Eating and chewing seems to be a conscious and even complex task. When we chew, we are often directing where the foo is, which muscles to move, an so on. It doesn’t seem reasonable for us to assume that animals do these behaviors we often see as simplistic in an unconscious way. We should probably assume that animals only unconsciously behave in the ways we unconsciously behave, as it seems more likely. That said, it could be possible that humans somehow evolved to be especially conscious about things like chewing or walking, but why would that be the case?

I think we use our intelligence to create new automatic and reflexive behaviors via learning. The purpose of learning is to reduce our need for conscious effort by automating all of our responses to the most predictable elements of some situation so that we don’t need to continuously address every detail of the problem every time. These reflexes that we create with learning are not necessarily motor reflexes, but probably even cognitive and even perceptual ones.

Moving back to plants, it doesn’t seem that plants have a need to use pain. They are not trying to decide whether they use their motor behavior to address pain or address hunger. They likely have some reflexive response that occurs when they have pain, regardless of the context, or perhaps with only some minor consideration of the context (perhaps assessing if it is heat damage versus being eaten).

However, I have imagined it to be possible for plants to generate something like sentience as a network of individual plants. Each plant could hypothetically operate like an individual neuron and a network of plants could operate like a brain in slow motion somehow. This is very speculative and I am not really convinced of this at the moment. It is a fascinating idea to me though.

As for non-human animals, I think many or very close to all experience something like pain or at least something like fear. I am less sure about insects, but I think we underestimate insects generally. Rather than lacking features like consciousness or perception, I think that they might have a potently simplified version of these. You could imagine that we have motor choices that include moving our hand in 3-dimensional space in a very fine-tuned way, potentially involving millions of possible choices, but perhaps an insect has 8 distinct choices instead, as opposed to having no choices and being a kind of “biological robot”.

Lastly, regardless of whether plants feel pain, the animals we kill for food are fed very many plants and they are spending the calories on metabolism, growing, and just being alive, so it is ineffective to eat animals as a method of protecting plants from pain or suffering.

What do you think about this topic?

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