Moral foundations theory (MFT) posits that human moral reasoning is based on innate, modular foundations, including care, fairness, loyalty, authority, and sanctity/purity.  According to MFT, political differences reflect variations in moral foundations: care and fairness matter more to liberals and loyalty, authority, and purity matter more to conservatives.

Unsurprisingly, MFT has found a receptive audience among progressives, who sometimes argue there’s no point in engaging political opponents on the merits of their beliefs because disagreements boil down to core values and progressive values are clearly superior. Fairness versus authority? No contest. Care versus purity? Please.  

MFT has been criticized as arbitrary, simplistic, reductionist, biased, essentialist, and lacking in explanatory power.  For more on these criticisms, check the references below. In this post, I’ll focus on the tendency of some commentators to overstate MFT research findings. For instance, in Behave: The Biology of Humans at Our Best and Worst, Robert Sapolsky concludes a discussion of MFT with the claim that “…conservatives heavily value loyalty, authority, and sanctity.” Say what!?

Yes, MFT has generally found that self-described conservatives value loyalty, authority, and sanctity more than self-described liberals, but that doesn’t mean conservatives value these moral foundations “heavily”. In fact, the research says otherwise. For instance, check out the results from Iyers et al:

_2019 MFT Means.png

To make sense of the above table, we have to go to the Moral Foundations Questionnaire. Part 1 of the questionnaire consists of statements, such as “Whether or not someone showed a lack of respect for authority”, with the instruction “When you decide whether something is right or wrong, to what extent are the following considerations relevant to your thinking? “ In Part 2, questionnaire takers are asked to indicate their level of agreement or disagreement with a series of sentences such as “Respect for authority is something all children need to learn”. A ‘3’ on the MFQ answer form means “somewhat relevant” to the items in Part 1 and “slightly agree” to the items in Part 2. Conservatives scored a mean of ‘3’ on all the moral foundations, a rather dispassionate moral profile. Hardly a heavy endorsement of anything.


Davis, Don E.,Rice, Kenneth,Van Tongeren, Daryl R.,Hook, Joshua N.,DeBlaere, Cirleen,Worthington Jr., Everett L.,Choe, Elise (2016) The moral foundations hypothesis does not replicate well in Black samples. Journal of Personality and Social Psychology, Vol 110(4), DOI: 10.1037/pspp0000056

Iyer R, Koleva S, Graham J, Ditto P, Haidt J (2012) Understanding Libertarian Morality: The Psychological Dispositions of Self-Identified Libertarians. PLoS ONE 7(8): e42366.

Liao S.M. (2011) Bias and Reasoning: Haidt’s Theory of Moral Judgment. In: Brooks T. (eds) New Waves in Ethics. New Waves in Philosophy. Palgrave Macmillan, London

Sapolsky, R.M. (2017) Behave: The Biology of Humans at Our Best and Worst.  Kindle Edition. New York, NY: Penguin Press

Suhler, C. L. and P. Churchland (2011). "Can Innate, modular "foundations" explain morality? Challenges for Haidt's Moral Foundations Theory." Journal of cognitive neuroscience 23(9): 2103-2116; discussion 2117-2122. DOI: 10.1162/jocn.2011.21637

Links to Prior ETPS Posts:

The Moral Foundations Questionnaire: an Apple Predicting Itself

Moral Intuitions, Political Identity, and the Feedback Loop

What Matters to Libertarians, Liberals, and Conservatives, Part IV