Summary
- This analysis estimates the expected moral weight of the beings of various species relative to humans for various types of moral weight distributions.
- The mean moral weight is close to 1 for all the considered species, ranging from 0.5 to 5 excluding the lognormal and pareto distributions (for which it is even higher, but seemingly inaccurate).
I welcome comments about how to interpret the results.
Methodology
The expected moral weight of the beings of various species relative to humans was determined from the product between:
- The probability of the beings of the species having moral patienthood, as defined by Luke Muehlhauser here, which was set to the values provided in this section of Open Philanthropy's 2017 Report on Consciousness and Moral Patienthood.
- The mean of a distribution whose 10th and 90th percentiles were set to the lower and upper bounds of the "80 % prediction interval" guessed by Luke Muehlhauser here for the moral weight of various species relative to humans conditional on the respective beings having moral patienthood (see "Moral weights of various species").
- The mean of the distribution was computed from the quantiles as described here.
The expected moral weight might depend on the theory of consciousness. The above product is implicitly assumed to represent the expected weighted mean of the moral weight distributions of the various theories of consciousness. These are, in turn, supposed to produce (summable) moral weight distributions. Potential concerns about calculating expected moral weights are discussed here.
Results
The mean and median moral weight of various species relative to humans for uniform, normal, loguniform, lognormal, pareto and logistic distributions were calculated here, and are presented in the tables below[1].
Species | Mean moral weight relative to humans | |||||
---|---|---|---|---|---|---|
Uniform | Normal | Loguniform | Lognormal | Pareto | Logistic | |
Chimpanzees | 0.900 | 0.900 | 0.490 | 3.27 | 0.900 | |
Pigs | 1.40 | 1.40 | 0.765 | 13.1 | 1.40 | |
Cows | 2.00 | 2.00 | 1.14 | 132 | 2.00 | |
Chickens | 4.00 | 4.00 | 2.41 | 1.50 k | 4.00 | |
Rainbow trouts | 4.55 | 4.55 | 3.00 | 28.4 k | 4.55 | |
Fruit flies | 2.50 | 2.50 | 1.95 | 2.46 M | 2.50 |
Species | Median moral weight relative to humans | |||||
---|---|---|---|---|---|---|
Uniform | Normal | Loguniform | Lognormal | Pareto[2] | Logistic | |
Chimpanzees | 0.900 | 0.900 | 0.0402 | 0.0402 | 0.00111 | 0.900 |
Pigs | 1.40 | 1.40 | 0.0335 | 0.0335 | 495 | 1.40 |
Cows | 2.00 | 2.00 | 0.0179 | 0.0179 | 99.1 | 2.00 |
Chickens | 4.00 | 4.00 | 0.0179 | 0.0179 | 49.5 | 4.00 |
Rainbow trouts | 4.55 | 4.55 | 0.00798 | 0.00798 | 8.67 | 4.55 |
Fruit flies | 2.50 | 2.50 | 0.00192 | 0.00192 | 0.310 | 2.50 |
Discussion
The results suggest animals and humans have a similar moral value. The mean moral weight is close to 1 for all the considered species, ranging from 0.5 to 5 excluding the lognormal and pareto distributions.
The lognormal distributions do not seem to represent the moral weights accurately. Their heavy right tails imply high mean moral weights, which would arguably require frequent strong experiences. However, as noted here by Jason Schukraft, "it appears unlikely that evolution would select for animals with a non-contiguous range that was exclusively extraordinarily strong because extremely intense experiences are distracting in a way that appears likely to reduce fitness".
The pareto distributions are not reasonable representions of the moral weights, as they lead to mean moral weights of infinity.
Loguniform distributions appear to be the best choice amongst the 6 studied types of distributions:
- Being positive, they prohibit negative moral weights.
- Having mean larger than the median, they are compatible with the intuition that the moral weight is a product (not a sum) of multiple dimensions (for example, clock speed of consciousness, unity of consciousness, and unity-independent intensity of valenced aspects of consciousness).
- Being bounded, they prevent unreasonably large mean moral weights.
- ^
The probability of pigs being moral patients is not provided in this section of Open Philanthropy's 2017 Report on Consciousness and Moral Patienthood. However, it was assumed to be equal to that of cows and chickens (80 %).
- ^
1 equals .
As a disclaimer, I came in with the preconception that one should assign near-zero probability of animals being of more moral relevance than humans.
After reading the arguments, I have found little to no convincing arguments contradicting this.
It's true that we should be uncertain as to how animals experience the world. However, I don't feel that the uncertainty in moral value should be thought of as ever exceeding human's moral value.
To illustrate my current understanding of the best way to think about this topic, I think all your probability distributions should probably be modeled as never exceeding 1 for every animal, as the probability of such an outcome is so low it's not worth considering. I think of it like the probability that you can build a perpetual energy-creating machine violating the laws of physics, or the probability that tomorrow the sun does not rise because the earth stopped rotating.
Perhaps, it could analogized as the same moral probability that causing suffering is a good thing, all things considered. One might argue that the human brain is extremely complicated, and morality is complicated, so we should put some weight on moral views that prefer to cause infinite suffering for eternity. Perhaps one could argue that some people enjoy causing others to suffer, and they might be right, and so suffering might be intrinsically good. I think this argument has about as much supporting evidence as the concept that animals could be more morally relevant than people. However, again, I would say the probability of such an outcome is so low it's not worth considering.
Although it's true we do not know the details of how animals experience consciousness, this is not enough to overturn the intuition all humans share about the morality of killing people versus animals -- one is simply entirely different than another, and there is no instance in which it is better to kill an animal than a person. This conception has apparently been held constant for many cultures throughout human history. In some cases some animals were revered as gods, but this was less about the animals and more about the gods. In some cases animals and living things were seen as equally valuable as humans. I think this is unlikely, but not impossible, but the key point is that killing was seen as wrong in all cases, and not that animals were seen as more valuable than humans.
Suffering is not the only relevant moral consideration. See "The Righteous Mind" by Jonathon Haidt -- humans probably share a few more moral foundations than purely care/harm, including authority, fairness, sanctity, etc. Some may view these as equally morally relevant. My point is here, it's questionable whether we have equal moral responsibility over nonhuman animals as we have to humans, depending on how you construct your moral frameworks. If you look at how human brains are wired, the foundations of our conceptions of morality are built with in-group vs out-group. So, the moral status of animals based on understanding of human psychology which is our best way to guess at a "correct" moral framework would indicate that as things become less like us, our moral intuitions will guide us as valuing these things less.
I think you may have come to your probability distributions because you are a sequence thinker and are using your intuitions to argue for each part of a sequence which comes to some conclusion, where the proper thing to do when coming to some conclusion about whether to spend on an animal welfare charity or not is to use cluster-style thinking.
I hope that this is seen as a respectful difference in perspective and not at all a personal attack. I think it is useful to question these sort of assumptions to make moral progress, but I also think we need a lot of evidence to overturn the assumption that humans are more or equally morally relevant than animals, in large part due to the pre-existing moral intuitions we all probably share. There don't appear to be sufficient arguments out there to overturn this position.
Okay, that was enough philosophizing, let me put in a few more points in favor of my position here: