The Righteous Mind by Jonathan Haidt has some interesting ideas about the different moral values of people who are liberal v conservative (in US political terms).
He argues that there are 6 key moral foundations that people base their values on:
Care/harm: cherishing and protecting others.
Fairness/cheating: rendering justice according to shared rules.
Liberty/oppression: the loathing of tyranny.
Loyalty/betrayal: standing with your group, family, nation.
Authority/subversion: obeying tradition and legitimate authority.
Sanctity/degradation: abhorrence for disgusting things, foods, actions.
People who have more left wing/ liberal politics tend to prioritize the first three, and have much lower levels of disgust etc, whereas people with more right wing/conservative views tend to value all 6 more or less equally. He goes on to claim that this is partly due to the way our individual brain s work and that the neurotransmitters which predispose us to our political views are inheritable.
I haven't actually read the book, just read reviews, and it sounds a bit far-fetched in places, but throws out some interesting ideas.