alt Hacker News>That has to be the universal one, no?
Not at all.
Some believe one should come to forgive their enemies. Some believe that one should purge one's enemies from life itself. Some believe that one should have no enemies.
Some believe that material wealth is fine to a point, some believe that the desire of possesing material wealth is a source of discontent, some believe that it is the source of many or all other discontents.
Some believe that wanting to improve one's station is a source of discontent.
Some are fine with removing life if it is inconvenient (like bugs) where others value the life of a bug equally to their own.
Some are okay with their friends and family members murdering foreigners actively engaged in warfare that threatens their own life and livelihood. Some are okay with their friends and family killing the friends and family of the enemy combatants. Some are okay with killing anyone just generally in the vicinity of enemy combatants. Some say literally poisoning the well is a step too far, but that we had to write that down is evidence of other's believing differently. Some believe it's okay to murder people, communities, and entire populations because they'd rather use the land for themselves, or maybe their noses are too long and their skin is indistinguishably different.
Rereading your comment, I see the "in group" disclaimer. What's the in group? Some believe it's just their family, the people on the block, the people who have lived within a certain number of miles for a certain number of years, citizens governed by a particular government, the citizens governed by a group of governments, the people living on a particular continent, people in general, humans in general, life in general, or everything. There are people to whom no human should ever murder another for any reason. You might agree with that in theory, but would you allow a conquering force that is literally raping your friends and family to simply do so unquestioned? Would you feel vindicated striking back? There are some who have decided that the morally correct thing to do is to simply quit the land and or life itself rather than to fight back, because to them murder is wrong period.
The good life is deeply personal and absolutely not universal.
But it all comes down to an expectation of some altruism. Yes you may vilify the out group but are the basic dynamics of helping your fellow person out really so different across space and time? I don't think so. Every culture has villages and relies upon others for mutual benefits. That is what I am talking about with this sort of universal baseline level of morality. Yes there could be a spectrum of acceptable cruelty but generally you have to think about these things in terms of a playground scenario vs the context that leads to a military operation involving poisoning a well. Would you play with someone who slapped you in the face and pulled your hair on the playground? No, and that is universal.