Morality is an “emergent property” of evolution. Seeing that all humans are largely the same in the major particulars of brain and mind — which includes our ability to develop a conscience — it’s no surprise that the same (or similar) moral sensibilities and attributes would emerge across the globe, even for communities that don’t know each other.
Here’s a plain fact: No theist who has ever lived — yeah, I’m about to make a huge claim — has been able to show a super-natural essence (deliberate hyphen for emphasis) of moral behavior that inextricably leads back or can be traced to some Celestial Being, who, as believers contend, is said to be a Moral Lawgiver. Sorry, but there is zero evidence that a Celestial Moral Lawgiver squirts or injects morality into human beings. I use “crude” language here — squirts, injects — only to dramatically underscore the ridiculousness of the theist’s view: the belief that humans are only moral creatures because we’ve been somehow given our sense of morality by an outside (and unseen) source. An objective source, one might say.