The bit about EQ was particularly interesting.(Encephalization Quotient is the ratio of the volume encapsulated by the brain to the volume of the animal. It serves as a stand-in for IQ in extinct species. Humans have an EQ between 5 and 8.)
It should be possible to examine current organisms, and classify them based on EQ and whether they have opposable thumbs. For each category, we could look at what fraction display abilities like tool use, communication, vocabulary size, and passing the mirror self-recognition test.
For example, perhaps the average EQ=1 animal without opposable thumbs has a vocabulary of 2 (alarm cries and mating signals) and doesn’t pass the mirror test. On the other hand, maybe half of EQ=4 animal with opposable thumbs display rudimentary tool use.
The actual range of abilities would give us our probability distributions for speculating about extinct animals. After some math to account for gaps in the fossil record 65+ million years ago, we should be able to estimate the probability that certain dinosaurs could use tools or pass the mirror test.
The hard part is determining the probability of developing civilization, given that a species displays certain marks of intelligence. We only have 1 data point, and anthropic principle makes it almost useless.
EQ is NOT the whole story. As I just noted above in another comment, there is amazing work on brain architecture coming out of the lab of Dr. Suzana Herculano-Houzel, a scientist studying neural structure across the vertebrates. I recommend her book, “The Human Advantage” and all the papers to have come out of her lab recently.
Three important things:
1 - Neural scaling laws differ from clade to clade. In a generic mammal, a brain 10x as large has only 4x as many neurons so there is diminishing returns to brain mass probably due to the need to maintain long connecting fibers. Primates break this relationship—all primate brains are roughly equally densely packed, and indeed are as densely packed as a generic mammal brain from a very small mammal. Something changed in primate embryonic development upwards of 50 megayears ago predisposing large primates to have much larger numbers of neurons (Practical example: turns out the cerebrum of an elephant is roughly equivalent to that of a chimp and the largest whales probably correspond to early homo erectus).
2 - Humans are actually incredibly generic primates. All of the pieces of our brains fall right on the primate trend lines in terms of size and cell number—our cerebrum is not oversized, its just that the cerebrum grows faster than other parts with increasing brain size across all the primates. We just happen to have the largest neuron number. And also, humans fall right on the body size to encephalization quotient trendline of all the primates, with only 3 primates falling off the trendline—chimps, gorillas, and orangutans are below the trendline with brains much smaller than you’d expect for their body sizes. She hypothesizes, for very sound reasons explored in their papers and her book, that this was due to energy constraints because brain tissue is energetically expensive, and that humans were able to get back onto the generic primate trendline and have brains as big as you’d expect for a primate of our body mass once we started cooking and could support the energy requirements of brain tissue.
3 - Birds are another clade that breaks the usual brain scaling laws. Their neurons do not get bigger with increasing brain size, much like primates, except that their neurons are ~6x as small as primate neurons. Thus, it turns out that corvids and parrots are packing brains equivalent to many monkeys that their EQ would never suggest.
As a side note, this might also be interesting, purely from a utilitarian standpoint. If insect suffering matters, that would completely dwarf all human moral weight, since there are 10^18 of them but only 10^9 of us.
However, perhaps we don’t care morally about animals which can’t pass the mirror test, on the assumption that this means they have no self-image, and therefore no consciousness. They could feel pain and other stimuli, but there would be no internal observer to notice their own suffering.
If that’s the case, animal welfare might still dominate over human welfare, but by a smaller margin. Doing what I described in the previous comment would let us estimate the value of future life in general, if we can determine to within an order of magnitude or so how much we value animals with various traits. This is critical for questions like whether terraforming mars is net positive or net negative.
I agree with you about the numbers: If there were say 10^15 insects then their moral weight might be in question. However there are actually more like 10^18, which is huge even for very small per-insect weightings.
The bit about EQ was particularly interesting.(Encephalization Quotient is the ratio of the volume encapsulated by the brain to the volume of the animal. It serves as a stand-in for IQ in extinct species. Humans have an EQ between 5 and 8.)
It should be possible to examine current organisms, and classify them based on EQ and whether they have opposable thumbs. For each category, we could look at what fraction display abilities like tool use, communication, vocabulary size, and passing the mirror self-recognition test.
For example, perhaps the average EQ=1 animal without opposable thumbs has a vocabulary of 2 (alarm cries and mating signals) and doesn’t pass the mirror test. On the other hand, maybe half of EQ=4 animal with opposable thumbs display rudimentary tool use.
The actual range of abilities would give us our probability distributions for speculating about extinct animals. After some math to account for gaps in the fossil record 65+ million years ago, we should be able to estimate the probability that certain dinosaurs could use tools or pass the mirror test.
The hard part is determining the probability of developing civilization, given that a species displays certain marks of intelligence. We only have 1 data point, and anthropic principle makes it almost useless.
EQ is NOT the whole story. As I just noted above in another comment, there is amazing work on brain architecture coming out of the lab of Dr. Suzana Herculano-Houzel, a scientist studying neural structure across the vertebrates. I recommend her book, “The Human Advantage” and all the papers to have come out of her lab recently.
Three important things:
1 - Neural scaling laws differ from clade to clade. In a generic mammal, a brain 10x as large has only 4x as many neurons so there is diminishing returns to brain mass probably due to the need to maintain long connecting fibers. Primates break this relationship—all primate brains are roughly equally densely packed, and indeed are as densely packed as a generic mammal brain from a very small mammal. Something changed in primate embryonic development upwards of 50 megayears ago predisposing large primates to have much larger numbers of neurons (Practical example: turns out the cerebrum of an elephant is roughly equivalent to that of a chimp and the largest whales probably correspond to early homo erectus).
2 - Humans are actually incredibly generic primates. All of the pieces of our brains fall right on the primate trend lines in terms of size and cell number—our cerebrum is not oversized, its just that the cerebrum grows faster than other parts with increasing brain size across all the primates. We just happen to have the largest neuron number. And also, humans fall right on the body size to encephalization quotient trendline of all the primates, with only 3 primates falling off the trendline—chimps, gorillas, and orangutans are below the trendline with brains much smaller than you’d expect for their body sizes. She hypothesizes, for very sound reasons explored in their papers and her book, that this was due to energy constraints because brain tissue is energetically expensive, and that humans were able to get back onto the generic primate trendline and have brains as big as you’d expect for a primate of our body mass once we started cooking and could support the energy requirements of brain tissue.
3 - Birds are another clade that breaks the usual brain scaling laws. Their neurons do not get bigger with increasing brain size, much like primates, except that their neurons are ~6x as small as primate neurons. Thus, it turns out that corvids and parrots are packing brains equivalent to many monkeys that their EQ would never suggest.
As a side note, this might also be interesting, purely from a utilitarian standpoint. If insect suffering matters, that would completely dwarf all human moral weight, since there are 10^18 of them but only 10^9 of us.
However, perhaps we don’t care morally about animals which can’t pass the mirror test, on the assumption that this means they have no self-image, and therefore no consciousness. They could feel pain and other stimuli, but there would be no internal observer to notice their own suffering.
If that’s the case, animal welfare might still dominate over human welfare, but by a smaller margin. Doing what I described in the previous comment would let us estimate the value of future life in general, if we can determine to within an order of magnitude or so how much we value animals with various traits. This is critical for questions like whether terraforming mars is net positive or net negative.
I actually drew up a spreadsheet to estimate this: https://docs.google.com/spreadsheets/d/1xnfsDuC0ddUxvKekGLJ5QA5nrXxzked7K-k6jqUm538/edit?usp=sharing
I agree with you about the numbers: If there were say 10^15 insects then their moral weight might be in question. However there are actually more like 10^18, which is huge even for very small per-insect weightings.