The feeling of disgust likely evolved as a mechanism to detect and avoid pathogens in the environment, but it also may explain why some people are more socially conservative than others, according to newly published research.
The study by John A. Terrizzi Jr., Russ Clay, and Natalie J. Shook will be published in the February issue of the Personality and Social Psychology Bulletin.
The researchers sought to examine why women are more likely than men to endorse the socially conservative attitudes of collectivism and religious fundamentalism. Both attitudes encourage cooperation with one’s own social group and the shunning of outsiders.
Women on average tend to adhere to social and religious norms, and practice within-group reciprocity more than their male counterparts. This and other observed sex differences in social conservatism have been attributed to differences in socialization processes. While men are taught from childhood to be independent and assertive, women are taught from childhood to be interdependent and cooperative. While men are taught to be leaders, women are taught to be caregivers.
“Females are more likely to exhibit forms of social conservatism that involve ingroup cohesion and outgroup avoidance (e.g., collectivism), which is consistent with the culturally accepted gender role of the female caregiver,” the researchers explained in their study.
Though socialization patterns do help explain how the sex differences in social conservativism emerge, the new study suggests there is also a biological basis to the differences.
Across four separate studies, the researcher found that those who were more easily disgusted and more afraid of contamination were more likely to be both female and socially conservative. The four studies were comprised of 980 undergraduate students in total.
The link between disgust and conservativism is bolstered by previous studies.
Research published 2012 in Social Psychological and Personality Science found disgust sensitivity was positively associated with political conservatism and the intention to vote for Republican president John McCain. Another study published 2011 in PLoS One found conservatives had stronger physiological reactions than liberals when shown gross pictures. Research published in the journal Emotion showed that disgust sensitivity was associated with unfavorable moral judgments about same-sex relationships.
But why do women tend to be more easily disgusted than men? The researchers think this can be attributed to evolution.
Men and women are both vulnerable to pathogens in the environment. However, the sexes face a distinct imbalance when it comes to reproduction. Women must bear approximately 9 months of pregnancy, while men’s “initial investment can be as little as the amount of time that it takes for copulation,” the researcher explained.
Women therefore have more to lose from mating with a bad partner. They also need to avoid exposing their gestating offspring to pathogens. Women with heightened feelings of disgust would have been more likely to avoid sickly mates and keep their fetus healthy, and consequentially more likely to pass on their genes.
Disgust, in turn, encourages “the preference of ingroup members over outgroup members, because outgroup members pose a greater disease threat,” the researchers wrote. This preference towards members of one’s own group manifests itself as socially conservative attitudes, like religious fundamentalism.
“In other words, disgust sensitivity prepares individuals to have a negative perception of others who may be a source of contamination and to avoid them.”