Disgust probably evolved as a mechanism to prevent us from ingesting dangerous substances, but it is also strongly linked to our sense of right and wrong.
According to research published in the journal Emotion in 2009, those who are more easily disgusted are also more likely to make implicit unfavorable moral judgments about homosexuals.
The study was conducted by Yoal Inbar, David A. Pizarro, Joshua Knobe, and Paul Bloom.
For their study, Inbar and his colleagues had 44 students from the University of California, Irvine read one of two scenarios. The first scenario described a music video that had the effect of encouraging gay men to French-kiss in public. The second scenario was almost identical, but instead of encouraging gay men to kiss, the scenario only states that the music video encouraged “couples” to French-kiss in public.
Although a participant’s sensitivity to being disgusted did not effect whether they explicitly considered homosexual men kissing in public to be right or wrong, it did seem to effect whether they considered the director of the music video to have intentionally encouraged gay kissing in public or not.
The scenario presented to the participants only described the music video as having the effect of causing gay men to kiss in public; it did not describe whether this effect was intentional or not.
Previous research has found “that people are more inclined to say that a behavior was performed intentionally when they regard that behavior as morally wrong.”
Inbar and his colleagues’ finding suggests that although disgust sensitivity may not effect explicit judgments about gay men, it may effect implicit and automatic judgments.
Furthermore, a second experiment conducted by Inbar and his colleagues found that disgust sensitivity was associated with negative implicit associations with homosexuality.
This second experiment used a test called the Implicit Association Test, which has been used to examine automatic associations with particular ethnic, social, or sexual groups.
“The Implicit Association Test, or IAT, is a computer task in which participants are asked to pair exemplars from one of two target categories with strongly positively or negatively valenced words,” as Inbar and his colleagues explain.
They found that compared to heterosexuality, the participants overall tended to associated homosexuality with negative words. As disgust sensitivity increased, so did the negative associations.
Neither experiment found that disgust sensitivity was associated with explicitly condemning homosexual behavior, but both studies found that it was associated with unconsciously or implicitly judging it.
But why is there an association between being easily disgusted and making implicit negative judgments about gay men?
Inbar and his colleagues note that humans may have evolved a “behavioral immune system” to avoid contact with groups of people that violated certain norms about food preparation, cleanliness, and sexual behavior.
“Individuals belonging to unfamiliar groups, especially those who engaged in unusual practices regarding food, cleanliness, and sex, posed a higher risk of carrying novel (and therefore particularly dangerous) infectious agents,” as they explain.
“Because gay people almost by definition engage in ‘unusual’ sexual behavior, one would expect more negative reactions to this outgroup on the part of those who are particularly disgust sensitive.”
Inbar and his colleagues also note that although disgust sensitive individuals may make these automatic negative judgments, they are capable of consciously overriding their intuition.
“It so happens that our fairly liberal sample of college students may be strongly motivated to reject initial intuitive judgments in certain domains because of a conflict with their conscious views of egalitarianism.”
Reference:
Inbar, Y, Pizarro, D.A., Knobe, J. & Bloom, P. (2009). Disgust sensitivity predicts intuitive disapproval of gays. Emotion, Vol 9, No 3: 435-439.