Thanks for this, which I read with interest! Can I see if I understood this correctly?
You were interested in finding a way to assess the severity of pains in farmed animals so that you can compare severity to duration and determine the total badness. In jargon, you’re after a cardinal measure of pain intensity.
And your conclusion was a negative one, specifically that there was no clear way to assess the severity of pain. As you note, for humans, we have self-reports, but for non-human animals, we don’t, so have to look for something else, such as how the animals behave. However, there is no obvious non-self-report method that would give us a quantitative measure of pain.
(from 1 and 2) We are forced to rely on our priors, that is, our intuitions, to make comparisons.
For what it’s worth, I agree with 1-3, but it does leave me with a feeling of hopelessness about animal welfare comparisons. Certainly, we have intuitions about how to do them, but we do not, as far I can see, have reason to think our intuitions are informed or reliable—what evidence would tell us we were wrong? So, I wonder if it would be true to say that making evidence-based (cardinal) animal welfare comparisons is not merely difficult (which implies they are possible) but actually not possible. I’m not sure what follows from this.
Even with humans, I wonder if self-reports of apparently cardinal pain intensities are just preferences over merely ordinal pain intensities, or otherwise imposing some cardinal structure that doesn’t actually exist in the pain itself. How could you tell?
Joel Michell argues that the theory of conjoint measurement provides indirect tests for whether psychological constructs are quantitative. I do not yet understand the approach in much detail or the arguments for alternative approaches.
I like your summary. I feel (slightly) less hopeless because I think…
Comparisons that involve multiple dimensions of pain are, in principle, possible. I think I would only regard them as impossible if I came upon evidence that pain severity is, in reality, an ordinal construct.
In one sense, I might be more pessimistic about this topic than many because I think it is plausible that many psychological constructs are ordinal.
Behavioral evidence could in theory license cardinal comparisons among different pains. Practical issues of feasibility (and permission from institutions) stand in the way, and I would grant that these will probably never be overcome.
Possibly, cardinal differences in severity are explicitly represented in the brain. If so, then in principle we could measure these representations, though I do not think that we ever will.
We may be able to prioritize between relieving severe pain and long-lasting pain without making direct cardinal comparisons, so long as we have a sense of just how many orders of magnitude pain severity can span. Many aspects of pain experience appear conserved across a large number of species. If we find that pain in humans or laboratory animals have a wide range of pain severity, then there is an above-chance possibility that farmed animals do too. There is also an above-chance possibility that the most severe pains on factory farms are close to the end of the negative side of the range, given that it is difficult to see the adaptive value of being able to represent threats more extreme than, say, being boiled alive.
I would agree that the point above is partly grounded in intuition that has only a vague relationship to a well-established theory of the evolution of pain. Hopefully, advances in this area will reduce our reliance on intuitions that are not grounded by a plausible scientific theory.
Thanks for this, which I read with interest! Can I see if I understood this correctly?
You were interested in finding a way to assess the severity of pains in farmed animals so that you can compare severity to duration and determine the total badness. In jargon, you’re after a cardinal measure of pain intensity.
And your conclusion was a negative one, specifically that there was no clear way to assess the severity of pain. As you note, for humans, we have self-reports, but for non-human animals, we don’t, so have to look for something else, such as how the animals behave. However, there is no obvious non-self-report method that would give us a quantitative measure of pain.
(from 1 and 2) We are forced to rely on our priors, that is, our intuitions, to make comparisons.
For what it’s worth, I agree with 1-3, but it does leave me with a feeling of hopelessness about animal welfare comparisons. Certainly, we have intuitions about how to do them, but we do not, as far I can see, have reason to think our intuitions are informed or reliable—what evidence would tell us we were wrong? So, I wonder if it would be true to say that making evidence-based (cardinal) animal welfare comparisons is not merely difficult (which implies they are possible) but actually not possible. I’m not sure what follows from this.
Even with humans, I wonder if self-reports of apparently cardinal pain intensities are just preferences over merely ordinal pain intensities, or otherwise imposing some cardinal structure that doesn’t actually exist in the pain itself. How could you tell?
Joel Michell argues that the theory of conjoint measurement provides indirect tests for whether psychological constructs are quantitative. I do not yet understand the approach in much detail or the arguments for alternative approaches.
I like your summary. I feel (slightly) less hopeless because I think…
Comparisons that involve multiple dimensions of pain are, in principle, possible. I think I would only regard them as impossible if I came upon evidence that pain severity is, in reality, an ordinal construct.
In one sense, I might be more pessimistic about this topic than many because I think it is plausible that many psychological constructs are ordinal.
Behavioral evidence could in theory license cardinal comparisons among different pains. Practical issues of feasibility (and permission from institutions) stand in the way, and I would grant that these will probably never be overcome.
Possibly, cardinal differences in severity are explicitly represented in the brain. If so, then in principle we could measure these representations, though I do not think that we ever will.
We may be able to prioritize between relieving severe pain and long-lasting pain without making direct cardinal comparisons, so long as we have a sense of just how many orders of magnitude pain severity can span. Many aspects of pain experience appear conserved across a large number of species. If we find that pain in humans or laboratory animals have a wide range of pain severity, then there is an above-chance possibility that farmed animals do too. There is also an above-chance possibility that the most severe pains on factory farms are close to the end of the negative side of the range, given that it is difficult to see the adaptive value of being able to represent threats more extreme than, say, being boiled alive.
I would agree that the point above is partly grounded in intuition that has only a vague relationship to a well-established theory of the evolution of pain. Hopefully, advances in this area will reduce our reliance on intuitions that are not grounded by a plausible scientific theory.