Haidt and his colleagues eventually recognized that their Moral Foundations Questionnaire was blinkered by liberal academic bias, failing to include a sixth moral foundation, liberty. They developed a liberty scale to probe this moral dimension. Unsurprisingly, the researchers found that libertarians dramatically outscored liberals and conservatives when it came to putting a high value on both economic and lifestyle liberty. Haidt and his colleagues conclude, “Libertarians may fear that the moral concerns typically endorsed by liberals or conservatives are claims that can be used to trample upon individual rights—libertarians’ sacred value.”
Next the researchers wondered, “Might libertarians generally be dispositionally more rational and less emotional?” On the standard inventory of personality, libertarians scored lower than conservatives and liberals on agreeableness, conscientiousness, and extraversion. Low scores on agreeableness indicate a lack of compassion and a proud, competitive, and skeptical nature. Like conservatives, libertarians are not generally neurotic, tending to be emotionally hardy. And like liberals, libertarians scored high on openness to new experiences, indicating that they have broad interests.
Libertarians scored lower than both liberals and (especially) conservatives on sensitivity to disgust. The authors suggest this tendency “could help explain why they disagree with conservatives on so many social issues, particularly those related to sexuality. Libertarians may not experience the flash of revulsion that drives moral condemnation in many cases of victimless offenses.”
Some of the more intriguing results involve the empathizer/systemizer scale. Empathizers identify with another person’s emotions, whereas systemizers are driven to understand the underlying rules that govern behavior in nature and society. Libertarians, unlike both liberals and conservatives, scored very high on systemizing.
I'm very skeptical of studies that purport to analyze the ethics of political groups. Too often, they serve merely to pathologize the groups that the study's authors dislike. And they rarely make any effort to distinguish between conservatives and libertarians, lumping them together instead. Haidt, at least, tries to make the distinction. Interesting results, that accord with my intuition.