I must stipulate that I found the investigation into the morality of animals quite amusing. It seemed very silly. If evolutionary biologists are to be the interpreters of morality they might take the time to consider philosophically the nature of what morality is as a concept in-itself, rather than to assume that a reductionist explanation of morality can be discovered by observing select animal interactions. Group behavior of animal groups tends to be for group survival. Female black widows eat their male partners because it promotes species survival. Animal groups have leaders and pay attention to their lead and disregard unimportant members, Lead geese in a wing follow the leader wherever. When the group splits a new leader arises in the new group and seeks to rejoin the lost wing.
Primates are group animals conditioned biologically through evolution to behave as a group and take pain cries seriously- it may mean the presence of a predator munching them. To remove primates from their natural environment and to regard their social interactions in a zoo as moral questions is quite silly. The group behavior is such that it promotes individual and group survival. It is amazing to watch schools of fish shift their position with simultaneous entropy because some lone fish in the school detected a threat. It is not a matter of the morality of fish.
While human behavior has some historical origins that are vestigial perhaps, the differentiation of human cultures as well as species variation among homo sapiens sapiens may have made some vestigial behavioral patterns differ. Yet human beings with intelligence and increased brain size developed thought that allowed them to choose to behave differently, willfully, rather than as a tribal member acting like a basketball team that was paid only if the entire team wins the first place championship trophy. If that were the case more selfless ‘morality’ would follow. Selfish players that just shoot to score and glorify themselves hogging the ball would be sold to other teams because the team wants to win and be paid.
Animals in the jungle-monkeys and chimps, had few defenses in soft bodies without useful claws as weapons. Group behavior; warnings and sharing, let the chimp D.N.A. continue. It did not teach them the morality of organized crime, kidnapping, murder, lying and so forth. Human morality arises at a higher level of self-awareness and thought. Though human morality has a social dialectical element that changes and evolves comparably to chimps and select other primates, it also has philosophical thought and a level of intentional, designed behavior that allows actual morality to be said to exist.
I have observed a wolf pack trotting along single file in a remote Alaska bay and saw the last wolf stop and look at me. I was armed with a large stick. It looked at me for a minute then trotted on to continue with the group. The wolf was not making a moral judgment. It may have been aware that I am human and not short. He was curious about a possible food source- they were probably hunting deer hoping to surprise one on the beach and variously through game trails in the wood. I thought as I observed the wolf that as the last in line he might not be regarded highly by the pack. If he had howled my presence the leader might have ignored him and thought “never cry wolf”, continuing on.
Harm and sympathy is different from fairness and reciprocity. The observations of select group behavior as being about fairness or reciprocity, one example was that of the Wall Street crash Occupy Wall Street protesters, with a minority of exceptions, might better be described as about proximal financial interest of those cheated or that lost money during the crash and/or those in support of a rival political system, yet few to none were objectively detached and making a moral protest about fairness and reciprocity I would guess. One might test that theory by determining if many quite economically independent and prosperous citizens were among the protesters. Even the WW I veterans bonus army march was more about actual financial injury to actual people than an abstract group of moral philosophers (excluding Cornell West in the Occupy Wall Street movement) protesting unfair political activity. https://www.britannica.com/event/Bonus-Army
The black hamlet fish’s hermaphroditic reciprocity was given as an example of fairness- I spoke too soon about sing fish as moral examples. Heterosexual reproduction I suppose is entirely unfair as it seems to be the way of mammals- suspected of having dubious ideas about morality. Reproductive method and sexual differentiation arose entirely before there was a semblance of moral awareness. The determination was that which best advantaged the species. I do not see the value to a course on human morality of animal behavior, except in so far as human behavior can be compared in the more rough aspects to that of animals. Modern American promiscuity for example, among females, is surpassed by that of female chimpanzees.
Something like disadvantageous inequity aversion could have several alternative explanations. One is that the last piece offered, of a good reward, might be what is in the short term memory, so an inferior piece might not be acceptable. Consider the dog that is fed steak every day; it might turn down dollar store dog chow for breakfast when it appears. I suppose that might be the dog morality of spoiled.
I would disagree with the principle that humans except with select brain lesions don’t accept unfair distributions. They do that all the time. Consider those that take immediate payouts from lottery winnings that are a fraction of what they would get if they waited and took payments. There are numerous examples in financial matters of individuals taking money that is less immediately than if they had waited for maturity. There is also the example of Congress giving the Bush II tax cuts to the rich permanently; the people were willing to accept virtually nothing while the rich and big banks got everything including zero-interest federal loans for years and years, from which they could issue their own e-dollars to loan at a rate of what five out of thin air bucks for every zero-interest federal dollar loaned to the banks. Ordinary people get nothing of that. What a scam.
On intraspecies aggression I would disagree that only humans and chimps are perps. Fish for example, eat other fish. Sometimes there isn’t much difference in species. Birds will eat other birds. If a bird dies o the beach, other birds will eat it. Among mammals peer aggression is usually dangerous because they are roughly equally armed and pawed. Mutually assured destruction and approximate balance have often kept wars from starting, though not always.
Humans have more empirical independence than animals to act self-deterministically regarding behavior for-others. Actors for instance are entirely false, yet true at once. They may enact violence for strange motives concerning thought or lack of it.
There was a old tired haggle-toothed bear that ate a photographic naturalist named Timothy Treadwell in Alaska a couple decades ago. The bear had trouble catching salmon evidently, but the humans looked like easy prey being trusting and on the ground. It was a hunger decision; not a moral one.
https://www.youtube.com/watch?v=Bhi-gBIJhAU audio of the bear killing the couple
On the chimp Gompe war it seems that because chimps- humans and chimps broke of evolutionary lines 16 million years ago- have better brain size, land tools for climbing and walking, group behavior and individuation the leads them to try out their capacities against other groups. There are numerous evolutionary reasons for the male competition, and killing of surplus males with the superior winning males having multiple reproductive opportunities with females. Humans developed a lot of technology and intelligence through war and territorial aggression. They are a little more progressed than chimps though, and have gone on a bit farther in the way of self-actualization to the point of leaving the group and being just an individual thinker and actor. Unfortunately mass social behavior and the mass social dialectic of humans in some cases has surpassed individual self-determination and occurs for macro-social leadership reason sometimes involving economics; why did President Obama stimulate and support wars from Libya to Syria that continue to this day?
There are many challenges to individuals and species in the contemporary human social environment. Mass political behavior through democracy or dictatorship of various kind isn’t intelligent enough to design human macro-infrastructure that is perfectly synergistic with the ecosphere and individual humans such that they become the best that they can be in the empirical world.
The Demonic males hypothesis exemplifies the environmental selection relation to animal behavior. It is not about morality at an advanced stage of consciousness. Applying the demon label to males is a hate label with religious connotations. Chimpanzees have no religion. They were not called unto salvation with the Lord Jesus Christ. Jesus has tried to renormalize human behavior. Aggressive godless academics reject that in preference for Wall Street wealth, war, and class racketeering forever more.
If humans were like bonobos then Neanderthal and Denisoven people might have triumphed.