Motivation and emotion/Book/2024/Disgust and hygiene

Disgust and hygiene:
How does disgust influence hygiene behaviours and what are the psychological mechanisms involved?

Multimedia presentation (3 min)

Overview

Scenario Figure 1. The immediate feeling of disgust compels you to avoid touching anything and wash your hands thoroughly. Imagine entering a public restroom with many people inside, where you experience the smell of a foul odour. In this scenario, this strong emotion experienced is referred to as disgust. The reaction to this odour may induce behaviours to improve or maintain one's cleanliness or hygiene.

Disgust is an ancient survival mechanism that is hardwired into our system to protect us from sensed dangers by motivating avoidant behaviour(s). However, disgust is not a general reaction as some people are more sensitive to it than others, leading to different hygiene habits and behaviours (see Obsessive Compulsive Disorder ). Disgust shapes an individual's daily decisions, for example, avoiding a sticky subway pole or obsessive wiping down surfaces (Olatunji et al., 2007). This chapter reviews the root of disgust, its role as a protective mechanism, and how it informs hygiene behaviours to emphasise further how this important emotion can be utilised in public health and disease prevention.

Focus questions: How does disgust function as a protective emotional response? What are the psychological mechanisms linking disgust to hygiene behaviours? How do individual differences in disgust sensitivity impact hygiene practices?

Understanding disgust

Disgust is a defence mechanism to keep people safe from toxins and illness. Beyond just physical responses, social and moral disgust also affects our interactions and behaviour. People differ in how sensitive they are to disgust, and this motivates how they choose to avoid perceived contaminants and how they maintain their daily hygiene.

Origin

Disgust is an ancient emotions that protects us from dangerous substances that could ultimately result in death. The feeling of disgust closely relates to the behavioural immune system, which Schaller and Park (2011) defined as a mechanism that includes "psychological mechanisms of the detection and further avoidance of the organisms carrying pathogens.".

From an evolutionary perspective, disgust likely developed to avoid ingesting toxic or spoiled food, infectious agents, or other harmful environmental circumstances. Disgust has thus evolved from what may threaten the body to moral and social disgust, in which taboo practices or actions result in similar emotional reactions (Rozin et al., 2008). Most disgust evokes the perception of contamination or violation of body purity. For this reason, disgust can be considered an evolutionarily selected defence mechanism for minimising contact with pathogens.

Disgust as a defence mechanism

Disgust has evolved to be an important protective mechanism that humans have against potential sources of sickness. The avoidance behaviours motivated by disgust (for instance avoiding spoiled food and avoiding contact with sick people) play a crucial role in minimising the probability of infection and getting sick (Curtis et al., 2011). This behavioural action reduces contact with carriers of infection agents, especially when those agents would not otherwise be visible or even detectable, as in the cases of bacteria and viruses.

The cue for this emotion comes with sensory signals of possible danger such as fluids of the body, decaying flesh and filth. Research has also indicated that disgust is not solely confined to physical contamination but also to social behaviours. For example, some social-interpersonal actions, such as betrayal or any form of social norm violation, may be well reflected in triggering another variant of disgust, namely moral disgust, which is adaptive in maintaining social bonding and preventing destructive behaviour against the members of one's group (Tybur et al., 2009). Hence why, people avoid these physical and social contaminants to avoid falling sick and putting themselves in a given social order.

Disgust and Hygiene Behaviours

Disgust is an adaptive mechanism used to avoid illness. It motivates hygienic practices, like hand washing, which are essential for avoiding disease. Disgust can be divided into three domains: moral, sexual, and pathogen. Pathogen disgust is strongly associated with preventive measures taken to prevent illness.

How disgust drives hygiene practices

Concerning hygiene behaviours, disgust is a primary motivator, and cleaning, washing, or sanitising would help people avoid contamination. Various studies found that the more disgusting a person feels, the more he or she is interested in washing his/her hands or refraining from touching a dirty surface (Curtis & Biran, 2001).

Most significantly, it manifests itself in health settings in that health workers who perceive disgust sensitivity show more concern for hygiene practices such as washing their hands and wearing gloves (Stevenson et al., 2009). There is a remarkable automatism in the association of disgust and hygiene with the elicitation of a disgust elicitor. For example, dirt or bodily fluids prompting immediate action to remove the contaminant. This is why the disgust-based intervention-public health campaigns using images of germs or dirty hands are a very efficient way of enhancing hygiene behaviours, such as washing hands, in cases of outbreaks of infectious diseases.

The role of disgust in everyday hygiene choices

Disgust controls individual choices regarding standard hygiene behaviours. It might become an obsessive cleaning of items someone touches, washing hands, or simply avoiding sights and places perceived as filthy. Many individuals avoid public restrooms due to their relationship with dirt and germs. Individuals with a high propensity for Disgust also try avoiding food consumption in places perceived as unhygienic (Olatunji et al., 2007).

Disgust influences consumer behaviour toward hygiene products such as disinfectants, hand sanitisers, and anti-bacterial soaps. Selling these products often depends on appealing to people's disgust sensitivity by overemphasising that one cannot see most hazards presented by germs and dirt. Thus, people make hygiene choices based on physical cues, such as visible dirt or perceived threats, such as invisible germs.

Psychological mechanisms of disgust

Disgust sensitivity: individual differences

Disgust sensitivity defines the degree to which an individual is disgusted by something. Individuals vary significantly in their susceptibility to disgust; this variation affects their hygiene practices. Individuals with high disgust sensitivity would be pretty observant of hygiene practices such as frequently washing hands, avoiding public restrooms, and cleaning the environment (Tybur et al., 2009). Individual differences may be traced to genetic causes and variations in early life experiences. One earlier hypothesis was that individuals who grow up in an environment where the perceived threat of contamination is high, for example, poor sanitation, develop heightened disgust sensitivity that extends well into adulthood (Stevenson et al., 2009).

Cognitive and Behavioural Links Between Disgust and Hygiene

The cognitive and behavioural links between disgust and hygiene intervenes to evoke the relationship between disgust and hygiene behaviours through behavioural and cognitive factors. Cognitively, it operates on a system of learned associations whereby given stimuli-for instance, dirt and bodily fluids-become associated in the mind with contamination and diseases. These cognitive associations then translate to avoidance behaviours wherein one would be disinclined to touch contaminated things or quickly wash one's hands after touching such things (Olatunji et al., 2007). It appeases the protective mechanisms against harm through behavioural means. The responses include hygiene behaviours like cleaning and disinfection and avoidance of direct contact with unclean surfaces. Hygiene behaviour is habitual over time through continuous learning from past experiences that have reinforced a relationship between disgusting stimuli and hygiene.

Evolutionary Perspective on Disgust and Hygiene

Most likely, Disgust has evolved as a protection against pathogens. Following the evolutionary theory, Disgust as supposed to be an adaptative reaction to avoid contamination: for example, spoiled foods, body fluids, and signs of disease - Schaller & Park, 2011. Immediately, this feeling of Disgust appeals to specific actions - for example, avoiding contaminated objects or cleaning to minimise chances of infection. This view has been instigated further by studies pointing out that disgust sensitivity is greater among individuals considering health and cleanliness a priority (Oaten et al., 2009).

Neural Mechanisms of Disgust

FMRI studies have also localised the activation of disgust to the anterior insula (Figure 2) and basal ganglia, brain regions involved in visceral and motor reactions. In this way, the disgust response can arise from emotive and physical responses, such as washing hands or avoiding objects perceived as contaminated (Calder et al., 2001).

Figure 2: Imaging of insular cortex, neural area related to disgust.

Cognitive-Behavioural Theories of Disgust

Cognitive theories support that feelings of disgust occur when an individual appraises the immediate environment for threats. For instance, Tybur et al. 2013 support that the emotional reactions of disgust include the cognitive appraisal of the risk of contamination; therefore, automated appraisals guide behaviours, including avoiding contact with contaminated objects and washing hands following exposure to unhygienically presented environments.

Disgust Sensitivity in Hygiene Behaviours

In literature, it has been highlighted that disgust sensitivity could be considered an essential predictor of hygiene behaviour; an individual reacts with greater sensitivity while increasing their engagement in behaviours of a preventive health character: hand washing, avoidance of public restrooms to avoid infectious diseases, etc. (Stevenson et al., 2009). This is true in environments where the perceived risk of contamination is high, such as hospitals or public transportation (Curtis & Biran, 2001).

Disgust as a Multidimensional Emotion

Disgust can be divided into several domains, including:

Pathogen Disgust: It is concerned with contamination and disease avoidance.

Social Disgust: the breach of social norms due to cruelty and deception.

Sexual Disgust: Related to inappropriate or unclean behaviours (Tybur et al., 2013).

This is important in the conceptualisation of these domains since different types of disgust variably influence hygiene behaviours. For example, whereas pathogen disgust is directly related to behaviours such as washing one's hands, moral disgust contributes to keeping oneself distant from others or avoiding certain public facilities (Curtis et al., 2011).

Real World Application

Disgust and Public Health Interventions

Our understanding of disgust has been used in public health communications to promote healthy hygiene behaviours. The disgust created from correct handwashing technique initiatives, either featuring dirty hand images or of contaminated surfaces, makes hygiene practices more probable among the populace, as shown by Reynolds and Seeger (2005). This was particularly important during pandemics, such as the Coronavirus Disease of 2019, when contamination avoidance was a critical factor in public health, as the World Health Organization (World Health Organization, 2020) showed.

Disgust in Educational and Public Spaces

Disgust can be utilised as an educational tool to enhance hygiene behaviour in children and the public. The concept of germs and contamination, combined with graphics that could create a moderate degree of disgust, is successful in hygiene handwashing in schools (Reynolds & Seeger, 2005). Similarly, visual reminders in public places such as bathrooms, airports, or other transportation hubs may also increase hand-washing or the use of hand sanitisers, especially when combined with themes of disgust about dirty hands or contaminated surfaces.

Disgust in Healthcare Settings

In the context of health, disgust serves as a crucial means for healthcare practitioners to act with good hygiene practices. Since they are in frequent contact with potentially contagious substances through bodily fluids, Personal Protective Equipment (PPE) (like gloves, masks, or hand sanitisers) is used. Acting according to proper hygiene guidelines, results in the safety of medical workers and their patients.

Over time, health professionals may become somewhat "desensitised" to disgust, whereby hygiene practices over time tend to worsen rather than improve (Davey, 2011). Hence, regular training and intervention programs pointing out the importance of hygiene are also relevant to practice consistency and safety.

Public health communications that express the disgusting nature of any infection/contamination have also been shown to increase health care professional's chances of practicing good hygiene. For example, hospitals that employ visual suggestions on the need for good hygiene practices and against contamination (such as through the display of fliers and posters showing pictures of germs) often record heightened levels of compliance to good hygiene practices (Curtis et al., 2011).

Disgust and Hygiene Across Cultures

Not every culture equally perceives disgust hygiene behaviour, for example, in more societies where pathogens are less common, through an exaggerated sense of disgust, people adaptively develop a tendency to avoid infection and therefore, have a likelihood of developing sickness (Stevenson et al., 2009). For instance, it has been highlighted that in cultures where food-borne illnesses are more common, hygiene behaviours regarding food avoid contaminants, such as uncooked or spoiled food are less practiced (Tybur et al., 2013). This also has implications for the public health campaigns themselves: Any promotion of hygiene practices must be framed with an awareness of cultural differences.

Besides variation in pathogen disgust, there is also variation in moral and sexual disgust that may indirectly influence hygiene practices. For instance, strict moral codes about purity and cleanliness in some cultures may fire stronger disgust responses and, hence, more frequent, or more elaborate hygiene rituals (Curtis & Biran, 2001). The understanding of such differences in the sensitivity of disgust are of importance for the development of public health programs that effectively promote hygiene behaviour accommodating for different cultures.

Disgust sensitivity in vulnerable populations

Sensitivity can be extreme in certain populations, for example, germaphobes or those afflicted with obsessive-compulsive disorder (OCD). Individuals with OCD often demonstrate a heightened disgust sensitivity, especially to contamination-related stimuli. Such heightened disgust sensitivity might give rise to compulsive cleaning and hand-washing behaviours, which, although, in the short-term alleviating anxiety, might become damaging to relationships, work etc. (Olatunji et al., 2007). For such populations, a clear understanding of the operation of disgust becomes very important for the building of treatments to manage these extreme responses without causing further distress.

[[File:Obsessive Compulsive Disorder (8970250666).jpg|thumb|Figure 3: Sorting M&M's by colour code is a common Complulsive behaviour

Case Study based on Person with OCD (Kaye, 2021) Steve is a 56-year-old male who generally has always felt anxious. Contamination and mistake-related fears over time mounted. Compulsions started, such as repeatedly washing one's hands and checking locks and windows. He develops anxiety about illnesses that he knows are irrational, but he checks and rechecks many things numerous times daily. It interfered with his work life and family life. Symptoms worsened, and John sought treatment. Fortunately, these compulsive behaviours subsided with the help of CBT incorporating ERP, hence helping him get his life back.

Quiz

1 What happens when someone has a strong sense of disgust?

	They avoid things that seem dirty or dangerous
	They become curious about gross things
	They ignore hygiene completely
	They want to touch everything

2 Why might people from different countries react differently to the same disgusting thing?

	Because everyone has the same experiences
	Because of different cultural backgrounds and traditions
	Because they all watch the same movies
	Because they all live in the same climate

Conclusion

Disgust is an adaptive emotional response developed to prevent individuals from coming into contact with dangerous substances or acquiring infections. According to psychological theories and studies, disgust is an adaptive emotion that fosters cleanliness to help prevent illness (Curtis et al., 2011). The two psychological mechanisms linking disgust to hygiene are through cognitive appraisal leading to avoidance behaviours of perceived contamination. However, such behaviours depend on variations in the degree of sensitivity to disgust. Individuals susceptible to disgust are likely to show frequent hygiene practices, whereas individuals of low sensitivity may require another approach to motivate (Tybur et al., 2013; Olatunji et al., 2007). Appreciation of this function of disgust does have some potential to help health promotion campaigns more effectively respond to individual differences with more effective health promotion.

See also

Disgust (Wikipedia)

Hygiene (Wikipedia)

Obsessive-compulsive disorder (Wikipedia)

References

Society of Clinical Psychology. Society of Clinical Psychology