That’s a good point. I hadn’t really thought about the issue in those terms. I’ll bring it up with the rest of the team and see what they think. Thanks!
Thanks for the comment. You’re right. Entomophagy is just one segment of the farmed insect sector. There are huge numbers of insects farmed for animal feed. There are also huge numbers of insects farmed for pollination and huge numbers of insects farmed as biological control agents (e.g., parasitoids that prey on crop pests). Then there’s silk, honey, shellac, carmine and a number of other products derived primarily from farmed insects.
All told, there are dozens of different types of insects farmed commercially. (And I’m just counting insects; if you include all invertebrates, the number is probably in the hundreds.) Right now we’re working on a project to get a better understanding of the number of insects farmed for various purposes and the conditions in which these insects are reared. Appealing to the “yuck factor” may be a way to put the brakes on one fast-growing segment of the farmed insect industry, but there is a lot more basic research that needs to be completed before we will be in a position to recommend concrete interventions.
Good catch! I had terrestrial gastropods in mind, so I’ve changed the original post from “class Gastropoda” to “order Stylommatophora” (which includes Helix pomatia, the most commonly consumed snail) to reflect this focus.
Hi Gavin! Thanks for your comment. It raises an important but extremely difficult question. The short answer is that nobody really knows what to say about moral weighting. Slightly longer answer below.
First, on consciousness. Strictly speaking, I don’t think it makes sense to talk about consciousness occurring on a scale. An entity is conscious if and only if there is something it is like to be that entity. If there’s any phenomenology, no matter how faint or weird, the entity is conscious. If there’s no phenomenology, the entity is not conscious.
Nonetheless, there are some aspects of consciousness that admit of gradations, and these gradations are plausibly morally significant. I’m pretty comfortable asserting that human experiences are ‘richer,’ in some sense of the term, than fruit fly experiences, and this difference in ‘richness’ is part of what accounts for differences in the moral value of fruit fly and human experiences. But it’s not clear to me how to spell out the appropriate sense of ‘richness.’ It’s certainly not as simple as number of sensory modalities. (I don’t think Helen Keller’s experiences were worth less than my experiences.) Phenomenal intensity is probably part of the answer but again not the whole of it. Elements of cognitive, emotional, or social complexity may also help determine moral weight. Philosophers are accustomed to talking about the moral value of agency, autonomy, rationality, and self-awareness. Those things might also factor into moral weight.
As for how to determine moral weight in practice, it depends of course on how we resolve the theoretical question, but I think there’s also going to be ample uncertainty here. There are probably some rough characterizations we can make, but in general I think we know too little about most invertebrates to be able to say much about their (relative) cognitive, emotional, and social complexity. I would love to be able to spend a good chunk of my career investigating these questions!
Thanks for the research advice! I can safely say that I never would have specifically targeted German research from the 50s to the 80s on my own initiative. One worry, though: how many of those papers are exclusively in German?
Hey Gavin. Once again, thanks for the wealth of insights and references! I have a few thoughts in response, but at this point it might be more valuable if we scheduled a videochat. I’m going to send you a message in a few minutes.
Thanks for another fascinating comment. Although we haven’t been framing the subject in this way (the Braitenberg reference is new to me), we’ve been thinking about similar issues for a long time. At an early stage of the project we had a spreadsheet that attempted to judge the extent to which a handful of robots and AI programs exhibited the 53 features we investigated for invertebrates. We de-prioritized the spreadsheet because filling it in required too many subjective judgment calls and we worried that the methodology we used to investigate invertebrate sentience wouldn’t be applicable to non-biological organisms. Ultimately, this is a question we hope to return to. There is ample material to explore: functionalism (and its denial) in philosophy of mind, graded states of consciousness, “evolution” in artificial reinforcement learning, the analogy between nonhuman animals and robots, and many others.
Thanks for the references, Gavin! You truly are an inexhaustible resource. The paper on uncertainty monitoring in ants looks particularly impressive and relevant. I hope to give it a full read later this week. The ability of eusocial insects to incorporate diverse streams of information into an integrated decision-making framework is, to my mind, decent evidence that they are conscious.
(Also, I’m getting a session timed out error on the aphid link.)
Hi Sammy. I’m one of the researchers on Rethink Priorities’ invertebrate sentience team. Thanks for your comment. This is an issue our team has thought a lot about and plans to address explicitly in forthcoming work. I agree that our research would be more digestible if we provided an overall probability of sentience for each taxon. Unfortunately, assigning a “sentience score” is extraordinarily difficult. The 53 features we investigated are not equally important, and the context in which they are displayed often makes a substantial difference to their evidential weight. One would have to have an expert grasp on biology, philosophy, and neuroscience (as well as lots of time on her/his hands) to even justifiably begin such a scoring project. And because subjective experience is, well, subjective, strict calibration in this domain is necessarily impossible.
Despite the above difficulties, Rethink Priorities is considering reporting our best guesses about the probability of sentience for our studied taxa. We are still figuring out the best way to present these preliminary estimates. We want the estimates to be viewed as hypotheses to be further refined (or perhaps completely abandoned) as more evidence comes in rather than hard conclusions that our work definitively supports. One concern is that interested parties might skip straight to our (uncalibrated, somewhat unjustified, extremely speculative) numerical estimates without taking the time to understand the nuance and intricacy of the issue. Personally, I worry that assigning sentience scores sacrifices too much in the name of digestibility.
Nonetheless, it’s not as if our currently published findings are completely silent on the matter. Clearly, there is better evidence for sentience for cephalopods and arthropods than there is for annelids and nematodes. Stay tuned for our invertebrate welfare cause profile (slated to go up in late July) for more on the implications of our research.
Thanks Gavin! I’ve added Beyond Boundaries to my reading list.
The potential connection between BCI and self-recognition is fascinating. Offhand, do you know any references for insect neural interface studies that might be comparable to the monkey example you describe?
(Apologies for the delayed response; I’ve been traveling the last few days.)
Again, thanks so much for the thoughtful and thought-provoking comments! My background is in philosophy, where the science of these issues gets handled at a rather superficial level, so it’s a pleasure to be able to correspond with someone with such a deep knowledge of the field.
The distinction between operant conditioning and operant conditioning with an unfamiliar action is somewhat arbitrary. We were trying to capture the fact that some types of learning require more cognitive flexibility than others. Perhaps the distinction between elemental and non-elemental learning is a more important one. There are probably a number of other important distinctions that I’ve either glossed over or just missed completely. I think it would be interesting to see a taxonomy of learning abilities and an analysis of which learning abilities give the strongest evidence for valenced experience. I certainly agree with you that contextual learning provides stronger evidence of cognitive flexibility than many other types of learning.
I’m interested to hear more about why you think novelty-seeking behavior might be evidence for the capacity for valenced experience. I suppose the fact that novelty salience can override innate preference is further evidence of behavioral plasticity. Is that what you had in mind or were you thinking of something more specific?
Definitely interested to hear your thoughts about navigation.
Gavin, if you have the time, I’d love to see references for those abilities. We’ve got another round of invertebrate posts coming out in mid-to-late July, and most if not all of your examples can be used to bolster the case that arthropods in general and insects in particular deserve a close look from the effective animal advocacy movement. Thanks for your contributions!
Thanks for the examples; keep them coming! Whether or not they possess the capacity for valenced experience, eusocial insects truly are remarkable creatures. Do you have an easy reference for the cuckoo bumblebee behavior? I’ve got a running list of amazing things different invertebrates do, and I’d love to add it to the list.
(On the subject of videos, check out the video I’ve linked in footnote 53. It always brings a smile to my face.)
Thanks for the compliment and especially for the thoughtful reply. I’ll take your comments in turn.
In the third part of the mini-series on features potentially relevant to invertebrate sentience, we discuss a number of learning indicators, including both classical and operant conditioning. That post is going up June 12. I would be interested to hear your take on the relevant sections.
There is certainly not going to be a perfect correlation between lifespan and potential for learning. (Indeed, there might not be any correlation at all.) The claim that we’re defending is that, in general, longer-lived organisms would benefit more from learning abilities than shorter-live organisms. We expect there to be exceptions both ways (i.e., relatively short-lived organisms that would benefit from learning abilities and relatively long-lived organisms that wouldn’t). Much depends on context of various kinds. Your point about the learning abilities of monarchs vs. bees is well-taken. In future work (to be published mid-July), we take an especially close look at eusocial insects, which are pretty amazing.
Your question about warning pheromones is a great example of a difficulty that has hounded us for the length of the project. Classifying and assessing complex behaviors is context-sensitive. I think you’re right that warning pheromones could fall into at least three categories. (Or maybe different pheromones fall into different categories?) Assessing the evidential force of these features is often even more context-sensitive. A behavior that looks like good evidence for sentience in one context doesn’t always look like good evidence for sentience in a different context. (e.g., a human reporting “I am in pain” is normally great evidence of painful experience. A very simple robot programmed to utter the same sounds is not great evidence of painful experience.)
Unfortunately, I don’t have any hard data to back up that claim, just extensive anecdotal evidence from roughly seven years interacting with professional philosophers and philosophy graduate students. And my anecdotal evidence skews heavily toward the US, so I’m not in a position to even hazard a guess about the prevalence of philosophy PhDs with STEM backgrounds in continental Europe. Sorry!