You are evolved to care about other beings, even if they’re unrelated, as well as yourself because of the iterated game theory inherent to living in the same social group. It’s a social compact.
Evolutionary ethics explains how human moral instincts arose over millions of years or primates being social animals, the last few million of which we were living in tribes of 25–100 people, which may or may not have got on with a few of their nearby tribes — so the size of the entire cooperating society was less than a thousand people (generally, under Dunbar’s number).
How we choose to apply those instincts in a society consisting of nation-states of tens-to-hundreds-of-millions of people, almost all of which nation-states are to various degrees either allied and trading with each other on a planet with a human population of about eight billion people, is a matter of sociology and politics. It’s pretty noticeable that “sense of fairness” is somewhat strained in any nation-state with a Gini coefficient significantly over 0, and is significantly more so across nation states. Objectively, international income redistribution via aid from rich to poor states has always been a lot less than that from rich to poor individuals within the same state. Similarly, most people find civil wars even more abhorrent than international wars.
However, evolutionary ethics pretty clearly doesn’t apply across species, with the arguable exception of animals we’ve domesticated long enough that we have to some extent symbiotically co-evolved with them (probably dogs, arguable cattle). Even pet animals, the non-humans most socially integrated into our societies, have very few rights compared to humans in basically all human societies: they are treated as moral patients to some degree, but they don’t carry equal moral weight to a human.
You are evolved to care about other beings, even if they’re unrelated, as well as yourself because of the iterated game theory inherent to living in the same social group. It’s a social compact.
Evolutionary ethics explains how human moral instincts arose over millions of years or primates being social animals, the last few million of which we were living in tribes of 25–100 people, which may or may not have got on with a few of their nearby tribes — so the size of the entire cooperating society was less than a thousand people (generally, under Dunbar’s number).
How we choose to apply those instincts in a society consisting of nation-states of tens-to-hundreds-of-millions of people, almost all of which nation-states are to various degrees either allied and trading with each other on a planet with a human population of about eight billion people, is a matter of sociology and politics. It’s pretty noticeable that “sense of fairness” is somewhat strained in any nation-state with a Gini coefficient significantly over 0, and is significantly more so across nation states. Objectively, international income redistribution via aid from rich to poor states has always been a lot less than that from rich to poor individuals within the same state. Similarly, most people find civil wars even more abhorrent than international wars.
However, evolutionary ethics pretty clearly doesn’t apply across species, with the arguable exception of animals we’ve domesticated long enough that we have to some extent symbiotically co-evolved with them (probably dogs, arguable cattle). Even pet animals, the non-humans most socially integrated into our societies, have very few rights compared to humans in basically all human societies: they are treated as moral patients to some degree, but they don’t carry equal moral weight to a human.