- 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.
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.
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.
|Species||Mean moral weight relative to humans|
|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|
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 .