Why are we not allowed to kill

[rory_20_uk]

Not to kill one's group is an evolutionary advantageous thing to do as then all can be looking out at threats rather than all looking every way. The the powerful ones who are expendible (men) can be stationwed at the rim whereas the weaker, more important ones (women, children) stay safe in the middle.

It's not the killing that has made us number 1, it's the eating. We can eat most things everywhere, and can even make food grow where it otherwise isn't to further boost numbers.

I'd say this is why we also are fine with "hunting" each other in "packs" as that is what is also an evolutionary advantage. Only killing what is perceived to be part of the "pack" is when we revile killings. Else they're a glorious victory.

This of course emcompasses armies in one sense, but also gang warfare where they'll happily kill each other's members for power and position.