BTW, although this is a silly and reductionist way to argue (history rarely yields much to universalizing regressions), it is perfectly possible to make the same argument in a subtle way, and to agree with what seem like their three basic points:
1) That there is, or at least was for a long time, a distinctive culture of honor in much of the South;
2) That that made men quicker to take offense and more prone to violence (as well as many other well known traits); and
3) That this was a culture that was transmitted overseas during the principle Scotch-Irish migrations.
^^^^^^^
CB: Probably , a complementary reductionist (but valid) argument, with this component a stronger influence than the history back in Britain, is that the Southern culture was prone to violence because so much violence had to be deployed to conquer the Indigenous Peoples and suppress and work the African slaves. The honor thing is just a shockingly hypocritical and phony rationale. Honor !? these were the most dishonest people in the colonies. Their whole system was a big lie. Although Calhoun came right out and said what it was; just that it was virtuous.
It's the new mode of production in the colonies, not so much the old one in Britain ,that is mainly determinitive : historical MATERIALISM, in this case. Concrete analysis of the concrete situation in the colonies.