Most Valuable Idea
If we look at personality traits liberals and conservatives care about harm & fairness (conservatives a little bit less). However conservatives naturally care more about purity (connects to conscientious in OCEAN personality trait model) and about the group (authority and in group loyalty)(there are a few animals that cooperate (wolf, dolphins, primates). Haidt encourages us to step out of the trap of binary thinking and think about this divide as complementary forces (yin-yang).
Humans are the only ones that did it in such a scale. So maybe it makes sense to preserve the values of group cooperation.
Conservatives think that societal order is not a default state but a fragile state that is hard to develop.