What matters is not that the 1st scenario is much more lilely than the 2nd under the hypothesis that pain is experienced (it clearly is). The relevant question is whether the 1st scenario is much more likely under the hypothesis that pain is experienced than under the hypothesis that pain is not experienced (it’s relation to the second scenario is irrelevant, a red herring). And whether this is actually the case is much less clear.
This is what your footnote equation says too, so I’m not disagreeing with that, but I think the way you presented the argument in the text hides this, and might lead someone to misunderstand what it is they are being asked to judge is ‘much more likely’.
You can make an evolutionary argument for why we would expect an animal to react ‘vigorously’ to sustaining damage, and it is not clear why this evolutionary explanation requires the pain to be ‘experienced’. So someone could make an argument that the likelihood of scenario 1 is high under both hypotheses, in which case it should only cause a small change in your priors.
I thought the post was really interesting, thank you for sharing it! It has updated me towards thinking that there’s a higher chance insects might be sentient. But I think things are still a lot more complicated than suggested by this reply.
Would be interested to hear from those who’ve disagreed with this, since I think I’m just pointing out a mathematical mistake? Interested to be corrected if I’ve got something wrong.
Perhaps would help to give some example numbers. Suppose someone assigns, for an insect:
P(react vigorously given pain experienced) = 1
P(react vigorously given no pain experienced) = 0.5
(These numbers seem defensible to me)
This gives you a Bayes factor of 2, when updating your probability that pain is experienced after seeing evidence that insects react vigorously to some negative stimulus. This is not a ‘strong’ update.
I think this is a misapplication of Bayes rule.
What matters is not that the 1st scenario is much more lilely than the 2nd under the hypothesis that pain is experienced (it clearly is). The relevant question is whether the 1st scenario is much more likely under the hypothesis that pain is experienced than under the hypothesis that pain is not experienced (it’s relation to the second scenario is irrelevant, a red herring). And whether this is actually the case is much less clear.
This is what your footnote equation says too, so I’m not disagreeing with that, but I think the way you presented the argument in the text hides this, and might lead someone to misunderstand what it is they are being asked to judge is ‘much more likely’.
You can make an evolutionary argument for why we would expect an animal to react ‘vigorously’ to sustaining damage, and it is not clear why this evolutionary explanation requires the pain to be ‘experienced’. So someone could make an argument that the likelihood of scenario 1 is high under both hypotheses, in which case it should only cause a small change in your priors.
I thought the post was really interesting, thank you for sharing it! It has updated me towards thinking that there’s a higher chance insects might be sentient. But I think things are still a lot more complicated than suggested by this reply.
Would be interested to hear from those who’ve disagreed with this, since I think I’m just pointing out a mathematical mistake? Interested to be corrected if I’ve got something wrong.
Perhaps would help to give some example numbers. Suppose someone assigns, for an insect:
P(react vigorously given pain experienced) = 1
P(react vigorously given no pain experienced) = 0.5
(These numbers seem defensible to me)
This gives you a Bayes factor of 2, when updating your probability that pain is experienced after seeing evidence that insects react vigorously to some negative stimulus. This is not a ‘strong’ update.