According to the sources on wikipedia, Brain synapses in foetuses do not form until week 17, and the first evidence of âminimal consciousness and ability to feel painâ does not occur until week 30.
This comment from a pro-choice author on my post on abortion discusses lines of evidence for the different views on when fetal pain arises. It seems to corroborate Calumâs perspective that Wikipedia editors are biased. From one of its linked studies (Derbyshire et al): âOverall, the evidence, and a balanced reading of that evidence, points towards an immediate and unreflective pain experience mediated by the developing function of the nervous system from as early as 12 weeks.â
Even if we grant some moral weight to a 15 week old foetus (which Iâm dubious of), itâs hard to see a logical reason why it would approach the morally significance of an adult chicken.
A 15-week fetus has an order of magnitude more neurons than an adult chicken. (Red junglefowl, the wild relative of chickens, have 221 million neurons, while 13-week fetuses have 3 billion brain cells. Since humans have a near 1:1 neuron-glia ratio, a 13-week fetusâs neuron count should be an order of magnitude greater than a chickenâs.) A chicken also has an underdeveloped cortex relative to mammals, which somewhat corresponds to the fetusâs developing cortex.
If anything, Iâd bet in favor of a 15 week fetus having more moral significance than an adult chicken rather than less.
It is bad scientific practice to cite a single study, rather than look for systematic reviews, because you can just cherry pick the one that matches your preferred outcome. It was relatively easy to find this systematic review, which sifts through hundreds of papers and concludes that:
the capacity for conscious perception of pain can arise only after thalamocortical pathways begin to function, which may occur in the third trimester around 29 to 30 weeksâ gestational age, based on the limited data available
Regardless, the relevant point is whether or not this pain, if it exists, is comparable in moral weight to the suffering of animals, which occur in greater numbers.
I could take issue with the 1:1 equating of neuron count with moral worth (which would imply that elephants are more important than humans), but it doesnât matter, because even if I accept your reasoning and say that fetuses are 10 times as important as chickens, the ~70 billion chickens killed each year would still outweigh the 10 million human fetuses by three orders of magnitude. I could then point out that cows have much more neurons than chickens, and are killed at numbers of 300 million per year.
I didnât cite a single studyâI cited a comment which referenced several studies, and quoted one of them.
I agree with your caveat about neuron counts, though I still think people should update upon an order of magnitude difference in neuron count. Do you have a better proposal for comparing the moral worth of a human fetus and an adult chicken?
I think the argument that abortion reduction doesnât measure up to animal welfare in importance is an isolated demand for rigor. I agree that the best animal welfare interventions are orders of magnitude more cost-effective than the best abortion reduction interventions. However, you could say the same for GiveWell top charities, Charity Entrepreneurship global health charities, or any other charity in global health.
A more precise reference class would be global health charities that reduce child mortality, like AMF.
When you are working with statistical trends, that can be true. But it is perfectly legitimate to highlight a single study with a very clear finding which is difficult to disputeâe.g. the existence of a certain kind of neuron. Moreover, the study we both cited was not a primary study, but was a review of sorts, from the worldâs leading expert in this areaâin turn, he cited multiple studies to develop his arguments. The systematic review you mention is, at the very least, outdated, and doesnât really give any kind of convincing response to the arguments laid out in Derbyshireâs paper.
Put another way, I would take one well-argued paper over a million poorly argued papers. If a paper is well argued and cites relevant and convincing arguments/âdata, it really doesnât matter if there are other papers which say the same thing or not. Unless another paper actually responds to those arguments and shows why they are badâthe conclusions remain perfectly valid. In short, I do not think there is any such general principle in science as âit is bad practice to cite a single studyâ - that really depends on oneâs purposes and oneâs conclusions.
This comment from a pro-choice author on my post on abortion discusses lines of evidence for the different views on when fetal pain arises. It seems to corroborate Calumâs perspective that Wikipedia editors are biased. From one of its linked studies (Derbyshire et al): âOverall, the evidence, and a balanced reading of that evidence, points towards an immediate and unreflective pain experience mediated by the developing function of the nervous system from as early as 12 weeks.â
A 15-week fetus has an order of magnitude more neurons than an adult chicken. (Red junglefowl, the wild relative of chickens, have 221 million neurons, while 13-week fetuses have 3 billion brain cells. Since humans have a near 1:1 neuron-glia ratio, a 13-week fetusâs neuron count should be an order of magnitude greater than a chickenâs.) A chicken also has an underdeveloped cortex relative to mammals, which somewhat corresponds to the fetusâs developing cortex.
If anything, Iâd bet in favor of a 15 week fetus having more moral significance than an adult chicken rather than less.
It is bad scientific practice to cite a single study, rather than look for systematic reviews, because you can just cherry pick the one that matches your preferred outcome. It was relatively easy to find this systematic review, which sifts through hundreds of papers and concludes that:
Regardless, the relevant point is whether or not this pain, if it exists, is comparable in moral weight to the suffering of animals, which occur in greater numbers.
I could take issue with the 1:1 equating of neuron count with moral worth (which would imply that elephants are more important than humans), but it doesnât matter, because even if I accept your reasoning and say that fetuses are 10 times as important as chickens, the ~70 billion chickens killed each year would still outweigh the 10 million human fetuses by three orders of magnitude. I could then point out that cows have much more neurons than chickens, and are killed at numbers of 300 million per year.
I didnât cite a single studyâI cited a comment which referenced several studies, and quoted one of them.
I agree with your caveat about neuron counts, though I still think people should update upon an order of magnitude difference in neuron count. Do you have a better proposal for comparing the moral worth of a human fetus and an adult chicken?
I think the argument that abortion reduction doesnât measure up to animal welfare in importance is an isolated demand for rigor. I agree that the best animal welfare interventions are orders of magnitude more cost-effective than the best abortion reduction interventions. However, you could say the same for GiveWell top charities, Charity Entrepreneurship global health charities, or any other charity in global health.
A more precise reference class would be global health charities that reduce child mortality, like AMF.
When you are working with statistical trends, that can be true. But it is perfectly legitimate to highlight a single study with a very clear finding which is difficult to disputeâe.g. the existence of a certain kind of neuron. Moreover, the study we both cited was not a primary study, but was a review of sorts, from the worldâs leading expert in this areaâin turn, he cited multiple studies to develop his arguments. The systematic review you mention is, at the very least, outdated, and doesnât really give any kind of convincing response to the arguments laid out in Derbyshireâs paper.
Put another way, I would take one well-argued paper over a million poorly argued papers. If a paper is well argued and cites relevant and convincing arguments/âdata, it really doesnât matter if there are other papers which say the same thing or not. Unless another paper actually responds to those arguments and shows why they are badâthe conclusions remain perfectly valid. In short, I do not think there is any such general principle in science as âit is bad practice to cite a single studyâ - that really depends on oneâs purposes and oneâs conclusions.