Animals Feel Pain Because Something Hurts
Feeling pain alerts an individual that something harmful isn't quite right.
Posted Jun 17, 2018
Because of my interests in the cognitive and emotional lives of nonhuman animals (animals), I was pleased to learn of an essay by Dr. Mirjam Guesgen titled "Animal pain is about communication, not just feeling." And, as I was reading it, a few comments popped into my email inbox with questions about some of what Dr. Guesgen wrote. There was some overlap in these notes, so here I just want to make a few comments because I expect Dr.. Guesgen's essay will be widely read because the topic of nonhuman animal pain is very popular and important. Her essay is available online, so here are a few thoughts about her stimulating piece, some of which might also be seen as correctives.
Dr.. Guesgen is correct in writing that pain "is an experience in itself, something that we subjectively feel." So, too, do other animals. She goes on to write, "But when it comes to the way non-human animals suffer, scientists have been surprisingly reluctant to consider that it’s anything more than a mere byproduct of being hurt." This isn't so. Perhaps some scientists take this point of view, but many others realize that there has been direct selection for animal pain and it is not an evolutionary byproduct.
Simply put, pain has evolved because it works to alert an individual that they're being harmed and that something is wrong. In his classic book The Nature of Selection: Evolutionary Theory in Philosophical Focus, renowned University of Wisconsin philosopher, Dr. Elliott Sober, distinguishes between two evolutionary processes, namely, selection for and section of different traits. Basically, when a trait is selected for it is targeted directly and when a trait appears coincidentally as a byproduct, there has been selection of that characteristic. So, for example, if a polar bear's coat was warm but not heavy, it would have been selected (the published paper can be seen here), but if it were heavy but not warm, it would not have been selected. Warmth, rather than weight, was selected for.
Adopting Dr. Sober's views of different types of selection, it's most likely that there has been selection for the ability to feel pain, and selection of the different ways in which pain is communicated to others. The ways in which pain is communicated are byproducts of direct selection for the ability to feel pain. Of course, it's the expression and communication of pain that are used to recognize and to assess pain in various animals, and these assessments are used to develop guidelines, regulations, and laws that are supposed to benefit the nonhumans.
Clearly, there's survival value in an individual being able to feel pain, and there's no reason why the ability to feel pain wasn't directly selected. And, it's essential to realize that nonhumans, similar to humans, show individual differences in how they openly express or mask pain. I've seen this in many different species including dogs, cats, and wild coyotes.
In putting forth her interesting idea that in addition to alerting an individual that something harmful is happening, it's also possible that something is being communicated to other individuals, Dr.. Guesgen considers various reasons why there has been "resistance to seeing non-human suffering as a kind of communication." One reason rests on timeworn and thoroughly incorrect and inane views of other animals as unfeeling machines. Suffice it to say, there's a rather sizable literature about how a wide variety of nonhumans communicate pain, and those who ignore the incredibly clear ways in which other animals express and communicate their pains are in deep denial about what solid science has clearly demonstrated, time and time again.
In her discussion of reasons why there has been resistance to viewing animal suffering as a kind of communication, Dr.. Guesgen also writes, "the extent to which animals are thoughtfully evaluating a situation and making decisions is unclear." This isn't so, and there are reams of data that show that a wide variety of nonhumans thoughtfully evaluate different situations and make informed decisions about what to do in these specific settings.
She also postulates, "If pain has evolved to be communicative, you’d expect social animals to show pain more than solitary ones, because they have someone to communicate with." This is an interesting idea that Dr. Guesgen notes needs further study. However, I would be very surprised to learn that this is so. The communicative aspects of feeling pain are most likely reflexive reactions -- perhaps facial expressions, vocalizations and scents -- that are byproducts of direct selection for the the ability to feel pain. They arise coincidentally -- there has been selection of these signals. In addition, the words "social" and "solitary" are difficult to define precisely, and some so-called social animals do very well on their own, and some so-called solitary animals can live harmoniously with others in different ecological conditions. If the communicatory aspects of "feeling pain" are coincidental traits (for which there has been selection of), it's more likely that "social" and "solitary" species wouldn't show any significant differences in the levels of pain they express overtly. However, they might show differences in the social situations in which they let others know they're in pain, if they're able to make this choice.
Lastly, Dr. Guesgen hypothesizes, "You might also expect natural selection to favour behaviour that’s honest, rather than manipulative, since showing pain risks revealing yourself as weak to predators." This is a very interesting suggestion that really needs to be studied further. Earlier in her essay she writes, "Indeed, many of the animals that show pain on their face, like rabbits, mice or sheep, are vulnerable prey animals." Other animals, including predators, also express their pain in different ways. It's also important to note that when an individual reveals she or he is in pain they also could be communicating this message to other group members and they could be putting themselves at a disadvantage. And, of course, animals who might not have evolved the ability to communicate pain or other feelings, still can feel pain and other emotions.
Thanks to Dr. Guesgen for writing her essay and for her debunking of outdated mechanistic views of other animals. My view is that we know considerably more than she suggests about nonhuman pain and the cognitive and emotional capacities of other animals. When Elliott Sober's ideas about different forms of selection are applied, the evolution of nonhuman pain is clearly explained: pain evolved because it alerts an individual that something is not quite right and she or he needs to get out of that situation. The ways in which it's communicated to others is coincidentally selected and may well have important communication/signal value, but they're not the main reason pain has evolved.
Please stay tuned for more discussions of why pain in other animals has evolved, not if it has evolved. Charles Darwin's ideas about evolutionary continuity make this abundantly clear. While there's no doubt that other animals feel deep and enduring pain, there's still much to learn about other aspects of these subjective and highly personal feelings. Pain matters to individual animals and it must matter to us.