Disgust and Morality
"[T]he idea that disgust plays a deeper role in people's everyday behaviour emerged only recently. It began when researchers decided to investigate the interplay between disgust and morality. One of the first was psychologist Jonathan Haidt at the University of Virginia in Charlottesville, who in 2001 published a landmark paper proposing that instinctive gut feelings, rather than logical reasoning, govern our judgements of right and wrong.
Haidt and colleagues went on to demonstrate that a subliminal sense of disgust - induced by hypnosis - increased the severity of people's moral judgements about shoplifting or political bribery, for example. Since then, a number of studies have illustrated the unexpected ways in which disgust can influence our notions of right and wrong."
Read more here: The yuck factor: The surprising power of disgust