Most of what each of us learns, whether moral or anything else, we learn via social osmosis.

I went to Catholic schools and we were taught our Catechism, which gave us all the moral absolutes very early in life. Protestant churches taught about morality in Sunday school.

In the United States I can think of no other place where morality is taught, of course, it is taught in the home but this is the parent passing on what they were taught in Sunday school or by the nuns or by social osmosis.

Our (American) culture has kept its hands off of teaching morality because everyone is reluctant to trespass on the territory that religion has classified as its own.