I believe that Jonathan Haidt’s Moral Foundations Theory as described in his book The Righteous Mind, in the many academic research papers he’s published, and in talks he’s given, many of which are available online, indicate that Moral Foundations perform the following functions:
1) They are the primary colors of the moral spectrum from which every morality can be comprised,
2) they are the color receptors of the moral eye – one for each primary color – which evolved in us because the primary colors are…
3) …the necessary ingredients – the tools in the tool kit – of human groupishness (i.e., cooperative society, civilization.)
4) They are evolved pattern recognition modules of (e.g., not unlike the ability to perceive patterns in color blindness charts) of social behavior, circumstances, and situations that correspond with the adaptive challenges and opportunities surrounding human groupishness,
5) evolved threat/opportunity detection modules that assess the perceived patterns,
6) modules of constant, automatic, subconscious “fast” cognition that can send signals upward into consciousness when a threat/opportunity is detected (i.e., intuition)
7) modules of occasional, conscious “slow” reason, with which we justify, defend, and attempt to persuade others that our intuitions are the right ones.
8) They structure the space of our thinking, which means that they define the limits and the extent of:
a. our capability to perceive, understand, and articulate, the social world, and therefore
b. the closed epistemic system that is a moral matrix.
9) Key components of fundamental human nature.