I read at least 2 analyses smarter than mine today...and maybe 3, plus a very good one yesterday. Two were by Jon Haidt in his book. One comment by Orphan Wilde at his blog. Yesterday, another smart comment here grew into a post at Perfidy's..
Because you can read Perfidy and Orphan at their places, I'll just point out what Haidt said:
1. There are 3 deep foundations for morality:
A. Individualistic -- We are all individuals.
B. Communitarian -- We are first parts of a community, and 2nd individuals
C. Divine -- We are first of all vessels that the divine animates
I personally live and breathe A...and I'm pretty sure it's genetic. Certainly my mom and my youngest son live there as well. Everyone else in my family to a lesser extent, but the 3 of us (mom, son, me) are ready to pull out the drones for that proposition. I encountered position B in Europe in 1993/4, trying to explain American libertarians to communitarians in Europe...and hitting a conceptual, non-language barrier. The notion "Community is a convenient, sometimes useful fiction...it is JUST individuals" did not compute at all...it was too foreign. I ranted about the difference in perspective for years after that. I don't understand C, and as far as I can tell, I am incapable of understanding C.
So long as you treat humans as atomic units...one ethics falls out (Harm/Care, Fairness, Liberty/Oppression). Indeed, libertarians like me are effectively moral dwarfs because we bail mostly on Harm/Care and Fairness/Cheating as well, and live exclusively in the political realm of Liberty/Oppression ... but it turns out (unsurprisingly) we live very strongly in the moral realm of liberty/oppression as well, and are relatively unimpressed by either fairness or harm/care claims, as compared to anyone else.
On the other hand, if you treat people as first units in a community (I am not, dammit), then the next 2 tribalist ethical lines fall out pretty quickly. Authority/subversion and Loyalty/betrayal are huge here. Community-first-ers automatically see them...and individual-first-ers automatically are blind. More likely...folks with strong authority and loyalty receptors drift towards a communitarian view, and folks with weak authority & loyalty receptors drift individualist.
Divinity-approaches also include strong components of the sanctity/degradation ethic. While I have huge disgust responses to food and bodily fluids...I think I'm nearly entirely free of them with respect to other stuff. Which makes religion in general very emotionally flat to me, as it's primary added appeal is to the disgust/sanctity/degradation ethic.
Aside...this makes hbdchick's obsession with inbreeding/genetic stock ever so interesting. America (and Australia) were founded by the folks who couldn't fit in with authority, and so the american people's natural constitution should be measureably different than that of those who stayed behind (on the authority/subversion and loyalty/betrayal lines). Also...the nuclear family structure of specifically Anglo- culture led to the strongest pro-liberty line in all of humankind. Asians and americans of other european, ( especially scandinavian) descent should like the authority model a lot better.
Remember...conclusions come first...reasons come second. If you have strong moral tendencies in any direction, you tend strongly to reach the conclusions that match your tendencies. Your brain is good at finding reasons...and higher IQ doesn't help you find contrary reasons at all. As far as we can tell, IQ purely for ex-post-facto justification of preferences.