in Charlottesville (March 19, 2012). Haidt's research on morality has led to publications and theoretical advances in four key areas.
Moral disgust Together with
Paul Rozin and
Clark McCauley, Haidt developed the Disgust Scale, which has been widely used to measure individual differences in sensitivity to
disgust.
Moral elevation With Sara Algoe, Haidt argued that exposure to stories about moral beauty (the opposite of moral disgust) cause a common set of responses, including warm, loving feelings, calmness, and a desire to become a better person. Haidt called the emotion
moral elevation, as a tribute to
Thomas Jefferson, who had described the emotion in detail in a letter discussing the benefits of reading great literature. Feelings of moral elevation cause increases in milk produced during lactation in breastfeeding mothers, suggesting the involvement of the hormone
oxytocin.
Social intuitionism Haidt's principal line of research has been on the nature and mechanisms of moral judgment. In the 1990s, he developed the
social intuitionist model, which posits that moral judgment is mostly based on automatic processes—moral intuitions—rather than on conscious reasoning. People engage in reasoning largely to find evidence to support their initial intuitions. Haidt's main paper on the social intuitionist model, "The Emotional Dog and its Rational Tail", has been cited over 7,800 times.
Moral foundations theory In 2004, Haidt began to extend the social intuitionist model to identify what he considered to be the most important categories of moral intuition. The resulting
moral foundations theory, co-developed with Craig Joseph and Jesse Graham, and based in part on the writings of
Richard Shweder, was intended to explain cross-cultural differences in morality. The theory posited that there are at least five innate moral foundations, upon which cultures develop their various moralities, just as there are five innate
taste receptors on the tongue, which cultures have used to create many different cuisines. The five values are: Later, in
The Righteous Mind, a sixth foundation,
Liberty/oppression, was presented. More recently, Haidt and colleagues split the fairness foundation into equality (which liberals tend to endorse strongly) and proportionality (which conservatives tend to endorse strongly). In this work, they also developed the new revised Moral Foundations Questionnaire-2 which has 36 items, measuring Care, Equality, Proportionality, Loyalty, Authority, and Purity. He has also made the case for Ownership to be an additional foundation.
"The elephant and the rider" One widely cited metaphor throughout Haidt's books is that of the elephant and the rider. His observations of
social intuitionism, the notion that intuitions come first and rationalization second, led to the metaphor described in his work. The rider represents consciously controlled processes, and the elephant represents automatic processes. The metaphor corresponds to Systems 1 and 2 described in
Daniel Kahneman's
Thinking, Fast and Slow. This metaphor is used extensively in both
The Happiness Hypothesis and
The Righteous Mind. ==Political views==