Thanks for the pushback, Henry!

The welfare ranges are extremely broad for the animals they do cover, and that's with questionable assumptions. I don't see how extending these to microbes would clarify anything.

I have come to believe this is a very fair objection. I believe you have acknowledged the uncertainty in RP's welfare ranges much better than me in the past. At the same time, RP extending their welfare range table to soil animals and microorganisms (which does not involve calculating welfare ranges; it would just be a literature review) would help decrease the uncertainty about their (expected hedonistic) welfare.

Imagine you knew all this information about nematodes. Still the fundamental question will remain how their "suffering" or "joy" compares to ours and how morally important it is.

Great point. I would currently prioritise decreasing the uncertainty about how the welfare of soil animals and microorganisms compares with that of humans over investigating ways of increasing their welfare. I asked RP 2 days ago about whether they "have any plans for projects decreasing the uncertainty of interspecies comparisons of expected hedonistic welfare".

I remain very puzzled how you ever see us getting low enough error bars on the joy/suffering of microscopic worms that we could make decision based on it.

I do not know about any intervention which robustly increases welfare, and I am not confident this will ever change. However, I do not think people should give up on increasing welfare before much more effort is put into decreasing the uncertainty about interspecies comparisons of expected hedonistic welfare.

Good to know you are considering it! You can try to mitigate social desirability bias by asking the humans to reply as if the question were really about real life situations.

Hi Wladimir.

In the Welfare Footprint framework, pain intensities are defined as absolute measures, meaning that one hour of Excruciating pain in humans is assumed to be hedonically equivalent to one hour of Excruciating pain in shrimps, if shrimps were capable of experiencing Excruciating pain.

How do you account for the possibility of an experience being neutral in the Welfare Footprint Framework (WFF), including due to lack of sentience? I believe the probabilities assigned to annoying, hurtful, disabling, and excruciating pain, and satisfaction, joy, euphoria, and bliss should add up to 1 - "probability of the experience being neutral", where "probability of the experience being neutral" >= "probability of sentience".

You have entries for "no pain" and "no pleasure" under WFF, as represented below. Are you modelling a lower probability of sentience by increasing the probability of painful experiences involving "no pain", and by increasing the probablity of pleasurable experiences involving "no pleasure"? If not, are your estimates for the time spent in time conditional on sentience? I think it would be better if you replaced the entries for "no pain" and "no pleasure" with a single entry for "no pain or pleasure (neutral experience)" such that the probabilities of all potential categories of experience add to 1.

Do you have any plans for projects decreasing the uncertainty of interspecies comparisons of expected hedonistic welfare? I think much more work on this is needed before concluding some interventions robustly increase animal welfare. I do not know about any intervention which robustly increases animal welfare due to potentially dominant uncertain effects on soil animals and microorganisms. Even neglecting these, I believe there is lots of room to change funding decisions as a result of more research on interspecies comparisons of expected hedonistic welfare. I understand Ambitious Impact (AIM), Animal Charity Evaluators (ACE), and the Animal Welfare Fund (AWF) use the welfare ranges you initially presented, or the ones in Bob Fischer's book as if they are within a factor of 10 of the right estimates (such that these could 10 % to 10 times as large). However, I can easily see much larger differences. For example, the estimate in Bob's book for the (expected) welfare range of shrimps is 8.0 % that of humans, but I would say one (not the only) reasonable best guess is 10^-6, the ratio between the number of neurons of shrimps and humans.

Thanks for the good points, Aditya! I wonder how one would increase the funding and researchers available for such research.

Thanks for the comment, Henry!

On 1, Rethink Priorities (RP) could extend their welfare range table to cover soil ants, termites, springtails, mites, nematodes, and some microorganisms. I would also like to see much more work informing interspecies comparisons of expected hedonistic welfare. RP's research agenda about interspecies welfare comparisons has some question about that. There could also be more research related to @Wladimir J. Alonso's and @cynthiaschuck's post on whether primitive sentient organisms feel extreme pain. "This discussion is part of a broader manuscript in progress, focusing on interspecific comparisons of affective capacities—a critical question for advancing animal welfare science and estimating the Welfare Footprint of animal-sourced products".

On 2, it would be helpful to have detailed descriptions of the life-fates of soil animals and microorganisms. Ideally, there would be a quantitative break-down of how organisms of a given species in certain conditions spend their time. For example, how much time they spend eating, drinking, mating, being eaten, being crushed, sleeping, and having certain diseases. I know about a private project proposal to investigate the life-fates of springtails, mites, or nematodes.

I know about 2 project proposals for researching the welfare of soil animals. They are not public, but one will most likely start next year. I hope there will be more related projects. People are welcome to fill this very short form if they are interested in funding research informing how to increase the welfare of soil animals.

Thanks for comment, Elijah!

I did not find a free version of Elizabeth's article Developing Valid Behavioral Indicators of Animal Pain, but I have now read this summary from Gemini, and this related article by Elizabeth. I agree with her that nociception does not necessarily imply sentience, but I do not rule this out. Here are some paragraphs I like from the article “All animals are conscious”: Shifting the null hypothesis in consciousness science by Kristin Andrews which relate to the article from Elizabeth you shared.

Given the determinate development of their nervous systems, 30-some years ago it was taken as given that C. elegans are too simple to learn. However, once researchers turned to examine learning and memory in these tiny animals, they found an incredible amount of flexible behavior and sensitivity to experience. C. elegans have short-term and long-term memory, they can learn through habituation (Rankin et al., 1990), association (Wen et al., 1997), and imprinting (Remy & Hobert, 2005). They pass associative learning tasks using a variety of sensory modalities, including taste, smell, sensitivity to temperature, and sensitivity to oxygen (Ardiel & Rankin, 2010). They also integrate information from different sensory modalities, and respond differently to different levels of intoxicating substances, “support[ing] the view that worms can associate a physiological state with a specific experience” (Rankin, 2004, p. R618). There is also behavioral evidence that C. elegans engage in motivational trade-offs. These worms will flexibly choose to head through a noxious environment to gain access to a nutritious substance when hungry enough (Ghosh et al., 2016)—though Birch and colleagues are not convinced this behavior satisfies the marker of motivational trade-offs because it appears that one reflex is merely inhibiting another (Birch et al., 2021, p. 31).

C. elegans are a model organism for the study of nociceptors, and much of what we now know about the mechanisms of nociception comes from studies on this species (Smith & Lewin, 2009). Behavioral responses to noxious stimuli are modulated by opiates, as demonstrated by a study finding that administration of morphine has a dose-dependent effect on the latency of response to heat (Pryor et al., 2007). And, perhaps surprisingly, when the nerve ring that comprises the C. elegans brain was recently mapped, researchers found that different regions of the brain support different circuits that route sensory information to another location where they are integrated, leading to action (Brittin et al., 2021).

Even if we grant the author's low confidence in nematodes' having marker five (motivational trade-offs), current science provides ample confidence that nematodes have markers one (nociceptors), two (integrated brain regions), four (responsiveness to analgesics), and seven (sophisticated associative learning). Given high confidence that nematodes have even three of these markers, the report's methodology would have us conclude that there is “substantial evidence” of sentience in nematodes.

The presence of pain markers in C. elegans and in other animals presumed to be unconscious has led to a rejection of some of these markers; for example, Elizabeth Irvine concludes that given the assumption that C. elegans are not conscious, the evidence that they possess nociceptors, engage in motivational trade-offs and show associative learning invalidates these three markers, and raise questions about others (Irvine, 2020). Irvine's worry about a marker's validity would only be strengthened were we to find evidence of it in a brainless animal, such as the sea sponge Porifera, since brainless animals appear to be even worse candidates for sentience. So let us turn to look at the sea sponge.

From the perspective of the lay observer diving through a reef, sponges themselves do nothing. However, sponges reproduce by creating larvae that swim from the parent and later sink and crawl to find a place to settle and metamorphosize into a new sponge. Our current knowledge of sponge larvae behavior is quite slight. What we do know is that the larvae demonstrate negative phototaxis, and their settlement time is increased by the introduction of substrates such as rubble and biofilm into the environment (Wahab et al., 2011). If it were to turn out that sponges engage in motivational trade-offs between light levels and rubble when it comes to selecting a place to settle, would that finding offer more evidence against motivational trade-offs as a marker, should it offer some evidence that sponges are sentient, or should that data imply neither? According to the sentience report's methodology, the answer is neither, but such evidence should not lead us to reject the marker of motivational trade-offs, either. Rather, high confidence in the presence of zero to one markers should lead us toward agnosticism about sentience in the species, and high confidence in one marker coupled with good research that fails to find the other seven markers should lead us to conclude that sentience is unlikely. On the sentience report's approach, and contra Irvine, the markers themselves are not open to being invalidated.

I skimmed the article Disentangling perceptual awareness from nonconscious processing in rhesus monkeys (Macaca mulatta) by Moshe Ben-Haim and others. I liked it, but I believe Kristin's criticism of defining markers of consciousness applies all the same.

I would like the focus to be on comparisons of expected hedonistic welfare across species and substrates (biological or not) instead of their probabilty of sentience. Relatedly, Rethink Priorities (RP) has a research agenda about interspecies welfare comparisons more broadly (not just under expectational total hedonistic utilitarianism).

Thanks for the additional context!

But regardless of the specific assumptions and whether that leads to 1.3x or 2.5x more birds in cages in China for meat than birds in cages for eggs globally, it probably doesn't really matter in terms of the general purpose of the post.

Agreed.

Great post, Jakub and Weronika!

• Anima International became increasingly worried that any effort to displace carp consumption may lead to increased animal suffering due to salmon farming requiring fish feed.

One could argue banning live carp sales is good due to improving attitudes towards animals, even if it may decrease the welfare of farmed animals. I think the case for chicken welfare reforms increasing animal welfare accounting for effects on non-target beneficiaries is also very uncertain. I estimate the effects on soil animals are much larger than those on chickens, and I have very little idea about whether the effects on soil animals are positive or negative. It might still make sense to prioritise banning live carp sales less relative to chicken welfare reforms if one is concerned about effects on non-target beneficiaries, and increasing animal welfare robustly. However, in this case, I think it makes much more sense to prioritise chicken welfare reforms less (at the margin) relative to understanding effects on soil animals, and decreasing uncertainty about interspecies welfare comparisons.

Overal I think more people who have insights on cause prio should be saying: if I had a billion dollars, here's how I'd spend it, and why. 

I see some value in this. However, I would be much more interested in how they would decrease the uncertainty about cause prioritisation, which is super large. I would spend at least 1 %, 10 M$ (= 0.01*1*10^9), decreasing the uncertainty about comparisons of expected hedonistic welfare across species and substrates (biological or not). Relatedly, RP has a research agenda about interspecies welfare comparisons more broadly (not just under expectational total hedonistic utilitarianism).