From this article by Kathleen McAuliffe:

Using a far cruder tool for measuring sensitivity to disgust — basically a standardized questionnaire that asks subjects how they would feel about, say, touching a toilet seat in a public restroom or seeing maggots crawling on a piece of meat — numerous studies have found that high levels of sensitivity to disgust tend to go hand in hand with a “conservative ethos.” That ethos is defined by characteristics such as traditionalism, religiosity, support for authority and hierarchy, sexual conservatism, and distrust of outsiders.

Using a far cruder tool for measuring sensitivity to disgust — basically a standardized questionnaire that asks subjects how they would feel about, say, touching a toilet seat in a public restroom or seeing maggots crawling on a piece of meat — numerous studies have found that low levels of sensitivity to disgust tend to go hand in hand with a “liberal ethos.” That ethos is defined by characteristics such as a dislike of tradition, low religiosity, a lack of support for authority and hierarchy, sexual exploration, and trust of outsiders.

In social science and popular writing about social science, liberal views are always the norm and conservative views are always deviations from that norm, deviations in need of explanation. Liberal views don’t need to be explained — after all, they’re so obviously correct.