Should you feel guilty about crushing bugs?
/As someone who has studied a variety of invertebrates before, during, and after getting my Ph.D., I am quite familiar with the dark side of this type of research: wholesale torture and murder of countless organisms in the name of SCIENCE! I remember one of my undergraduate advisors, Erika Iyengar, saying that she was going to “snail hell” for all the horrible things she had done to snails over the years. Entomologists are particular offenders, as they often kill thousands of bugs on a regular basis to collect their data. Some of the experiments I conducted in graduate school would be considered psychological warfare, were I ever to be put on trial by a panel of spiders. Arachnid judgment would be rather harsh, I think, and also an amazing movie idea.
The point of all this is that researchers who study invertebrates get to do horrific things to their subjects without oversight. The underlying assumption is that these creatures do not feel pain, or at least not pain as we understand and experience it. Clearly, insects and other critters respond to damaging stimuli and move away, known as nociception. The question is whether they feel pain. The difference between nociception and pain lies in subjective brain states (i.e., what something feels like), about which we actually know very little in humans and basically nothing in other organisms.
Bug brains are small and more widely distributed in their bodies than our brains, but these differences are only structural and cannot prove that bugs don't feel pain. What about function, the evil twin* of structure? Well, bugs clearly behave in ways to avoid damaging stimuli, but this only demonstrates nociception, not the internal experience of pain. Sure, bugs may do some non-human things when damaged, but that doesn't mean they don't experience pain as we do.
Behavior does not provide the insight sufficient (or necessary) to determine whether or not bugs have subjective, internal experiences of pain. Interestingly, robots and artificial intelligences can be programmed to behave in ways consistent with experiencing pain. Does this mean they feel pain? I think that question is as hard to answer as when the same question is asked about bugs. Arguments about the evolution of experiencing pain are not convincing to me, and rely on lots of assumptions for which I see little support. Furthermore, these arguments point towards human exceptionalism: why should we have evolved to feel pain, but not other species?
The author of the article (linked below) ends up at a question: “Are insects more like little people or are they sophisticated robots?”. Little people feel pain, whereas sophisticated robots do not. Unfortunately, but not surprisingly, there is no good answer to this question; we cannot know whether bugs feel pain. The author expresses hope that technological advances will provide more insight, but I think the whole endeavor is hopeless. Brain states are hallucinations created by emergent properties of self-referential neural architecture.
If you re-read this blog post and replace words like “bugs”, “insects”, and “critters” with “other human beings” you quickly realize a fundamental problem in philosophy. There is no way to tell that anyone other than yourself experiences pain or other subjective brain states. Sure, we can use words and body language as indicators of internal experiences, but they're just that: indicators. If something else (a bug, a chimpanzee, a computer?) could provide these indicators when we'd expect them, would we conclude the existence of pain as we understand it within our own bodies? Conversely, if these indicators did not appear in an otherwise seemingly normal person, would we conclude the absence of pain? This is a deep philosophical issue that has received much attention from philosophers, with no clear solution provided or in sight.
*structure and function are intricately linked and simultaneously shaped by evolution. One of them has to be evil, though. Right?