Ryan Ritter and Jesse Preston have extended this literature to show that religious beliefs that contradict one's own also leave a bad taste in the mouth, literally.
The genius in this study is the cover story. Eighty-two Christian student participants were told they were taking part in two separate investigations: one a marketing survey requiring that they taste two different drinks; the other a study of handwriting and personality. The participants first tasted a lemon-based drink and rated it. Then, ostensibly to allow their palates to refresh, they completed the handwriting task, which involved them copying out either a neutral text (an intro to a dictionary); a section from Richard Dawkins' The God Delusion (in which he describes the God of the Old Testament as "arguably the most unpleasant character in all fiction"); or a section from the Qur'an (from Surah 47: 1-2). A personality questionnaire helped embellish the cover story. Finally, the students tested the second drink and rated it. A handful of participants guessed the true purpose of the study and were excluded from the analysis.
In reality the two drinks were identical and the key measure was how the participants responded to the drink after exposure to religious beliefs that contradicted their own. The findings were clear: the Christian participants reported finding the drink far more disgusting after they'd written out a passage from either Richard Dawkins or from the Qur'an. In contrast, their ratings of the drink were unchanged after writing out the neutral passage.
A second study was similar to the first, but this time some of the participants had a chance to clean their hands with an antiseptic wipe after writing out a passage from the Qur'an, from Dawkins, or from the Bible. Once again, exposure to Dawkins or the Qur'an (but not the Bible) heightened participants' disgust reaction to the drink, unless, that is, they had a chance to clean their hands.
Other ratings of the drink, such as bitterness or sourness, were unaffected so this was a specific effect on disgust. Also, general negative affect was unable to explain the results.
"The present research provides evidence that contact with rejected beliefs elicits disgust," the researchers said. "Whereas the majority of past work on moral purity has focused on disgust in response to morally questionable objects and actions, these data suggest that contact with outgroup religious beliefs may be an equally threatening source of impurity, and can literally leave a bad taste in the mouth."
Future research is needed to see if it's necessary for people to write or say rejected religious beliefs in order to experience disgust (perhaps by provoking the feeling that they've violated their own sanctity) or if instead mere contemplation of the material suffices. Ritter and Preston also plan to test the reactions of people from other religious groups and the effect of rejected non-religious beliefs - in all cases they predict morally rejected beliefs will elicit physical disgust.
RS Ritter and JL Preston (2011). Gross gods and icky atheism: disgust responses to rejected religious beliefs. Journal of Experimental Social Psychology, 47 DOI: 10.1016.j.jesp.2011.05.006
Post written by Christian Jarrett for the BPS Research Digest.