The Social Origins of Disgust

Joshua Rottman, Jasmine M. DeJesus, and Emily Gerdin
Forthcoming in The Moral Psychology of Disgust (Nina Strohminger and Victor Kumar, Eds.)

Despite being perfectly nutritious, consuming bugs is considered gross in many cultures
(Ruby, Rozin, and Chan 2015). This disgust reaction carries severe consequences. Considering
the negative environmental impacts of the growing consumption of beef, poultry, and fish, the
United Nations Food and Agriculture Organization has identified eating insects as a sustainable
solution for maintaining protein-rich diets (van Huis et al. 2013), but the prevalent disgust
reaction to this initiative presents a substantial hurdle. What is the function of such an irrational
response, one that may continue to endanger the natural environment? Do people experience
disgust toward insects because of perceived disease risks? Are people reacting to the reminder
that they are eating an animal, in the same way that many people react negatively to eating a
whole fish (with its head and eyes) compared to a fish fillet? We argue that social risks may
instead be motivating this reaction. More broadly, moving beyond the example of entomophagy,
we claim that disgust is much more deeply enmeshed in social and moral considerations than has
been previously acknowledged.

The scientific study of disgust has been predominantly concerned with uncovering its
ultimate adaptive purpose. Theories about the function of disgust abound, ranging from the
abhorrence of disorder and ambiguity (Douglas 1966) to an existential recoiling from reminders
of mortality and animality (Becker 1973; Goldenberg et al. 2001; Nussbaum 2004). However, a
clear front-runner has emerged amongst these diverse proposals: Disgust evolved because it has
helped humans to avoid physical contact with poisons, parasites, and pathogens. In this chapter,
we propose an alternative to the recurrent claim that disgust evolved for the sole purpose of
facilitating the avoidance of toxins and infectious disease (e.g., Chapman and Anderson 2012;
Curtis 2011; Curtis and Biran 2001; Davey 2011; Rozin and Fallon 1987; Rozin, Haidt, and
Fincher 2009; Schaller and Park 2011; Stevenson, Case, and Oaten 2009; Tybur et al. 2013).
Because this paradigmatic idea posits a purely physical (i.e., non-social) reason for the existence
of disgust, we refer to it as the “Physical Origins” hypothesis.

The book chapter is here.

Individual Differences in Moral Disgust Do Not Predict Utilitarian Judgments, Sexual and Pathogen Disgust Do

Michael Laakasuo, Jukka Sundvall & Marianna Drosinou
Scientific Reports 7, Article number: 45526 (2017)
doi:10.1038/srep45526

Abstract

The role of emotional disgust and disgust sensitivity in moral judgment and decision-making has been debated intensively for over 20 years. Until very recently, there were two main evolutionary narratives for this rather puzzling association. One of the models suggest that it was developed through some form of group selection mechanism, where the internal norms of the groups were acting as pathogen safety mechanisms. Another model suggested that these mechanisms were developed through hygiene norms, which were piggybacking on pathogen disgust mechanisms. In this study we present another alternative, namely that this mechanism might have evolved through sexual disgust sensitivity. We note that though the role of disgust in moral judgment has been questioned recently, few studies have taken disgust sensitivity to account. We present data from a large sample (N = 1300) where we analyzed the associations between The Three Domain Disgust Scale and the most commonly used 12 moral dilemmas measuring utilitarian/deontological preferences with Structural Equation Modeling. Our results indicate that of the three domains of disgust, only sexual disgust is associated with more deontological moral preferences. We also found that pathogen disgust was associated with more utilitarian preferences. Implications of the findings are discussed.

The article is here.

Sick in the head? Pathogen concerns bias implicit perceptions of mental illness

By Erick M. Lund and Ian A. Boggero
Evolutionary Psychology 12(4): 706-718

ABSTRACT

Biases against the mentally ill are historically and cross-culturally pervasive, suggesting they may have an evolutionary basis. The prevailing view is that people seek to distance themselves from the mentally ill because they are perceived as dangerous, violent, and incompetent. However, because of similarities between sickness behaviors and symptoms of some mental disorders, it was hypothesized that mental illness stigma could be partially explained as a function of behavioral immune system biases designed to avoid potential sources of contagion. In two experiments, it was found that mental illness was implicitly associated more with disease than danger. In Experiment 1, this implicit association was exacerbated among people who have had their biological immune system activated by a recent illness. In Experiment 2, experimentally priming disease salience increased implicit association between mental illness and disease. Implications for the evolutionary origins of prejudice and the prevention of mental illness stigma are discussed.

The article is here.