What is a "default" human mode, though ? As I said on a sibling thread, there do exist examples of apparently successful social engineering efforts. For example, in most of the developed world, outright slavery was not only eliminated but rendered morally repugnant, and this change does not show any signs of reversal. To use an older example, monogamy became the social norm sometime during the Middle Ages (IIRC), and it persists as such to this day -- despite the fact that humans are biologically capable of polygamy.