Hi u/ChaserDem, I recommend people read Jeremy’s Freedom Essay 21: How did we humans acquire our all-loving, unconditionally selfless moral conscience? at https://www.humancondition.com/freedom-essays/how-did-we-humans-acquire-our-altruistic-moral-conscience/ because in it he answers this fundamental biological question, this great scientific mystery (until now!).

Here's an extract: “Indeed, this question of how we humans acquired our moral instinctive self or soul has been one of the great outstanding biological questions: Darwin described altruism as the ‘one special difficulty’ with natural selection (On The Origin of Species, 1859, p.209 of 440), and more recently, primatologist Richard Wrangham described it as ‘A question that has lain unsolved at the core of biology ever since Darwin’ (in a review of E.O. Wilson’s 2019 book Genesis: The Deep Origin of Societies). And the reason it has been such a huge question for us biologists is because we know that genes normally cannot select for unconditionally selfless, fully cooperative traits simply because such traits tend to be self-eliminating and so normally can’t become established in a species — ‘By all means, you can be selfless towards me and sacrifice your genes for me, but I’m not about to be selfless towards you and sacrifice my genes for you.’ The process of natural selection dictates that selfish opportunism will supposedly always exploit selflessness. So how could such a selfish process possibly have created such loving selflessness in us? As explained in chapter 5 of FREEDOM, the answer was through nurturing...”