A study published in the February issue of Science argues that the evolutionary roots of moral disgust may be linked to our reaction to poison and disease:
In the study, the scientists examined facial movements when participants tasted unpleasant liquids and looked at photographs of disgusting objects such as dirty toilets or injuries. They compared these to their facial movements when they were subjected to unfair treatment in a laboratory game. The U of T team found that people make similar facial movements in response to both primitive forms of disgust and moral disgust . . . .
“These results shed new light on the origins of morality, suggesting that not only do complex thoughts guide our moral compass, but also more primitive instincts related to avoiding potential toxins,” says Adam Anderson, principal investigator on the project and the Canada Research Chair in Affective Neuroscience. “Surprisingly, our sophisticated moral sense of what is right and wrong may develop from a newborn’s innate preference for what tastes good and bad, what is potentially nutritious versus poisonous.”
So people make similar facial movements when they are morally repulsed or when they taste something sour. Ergo, morality is really just a primal self-defense mechanism to avoid drinking poison. Whew. Scientific reductionism sure makes life easier.