Motivation and emotion/Book/2019/Disgust and vegetarianism and veganism

Overview
Meat dishes are very common cross-culturally, yet the environmental impact of meat consumption is possibly the most significant cause of environmental degradation, including waste, energy and water consumption, greenhouse gas emissions, and biodiversity loss (Palomo-Velez, Tybur, & van Vugt, 2018). While meat is enjoyed by many people now, the longer-term cost through environmental degradation will be shared by all, therefore reducing meat consumption seems vital. A body of research found that persuasive arguments about health concerns, environmental degradation, and animal welfare have limited effectiveness. Researchers were looking for alternative strategies to reduce motivation to eat meat (Palomo-Velez, Tybur, & van Vugt, 2018).

Animal welfare concerns have been found to be a major factor in becoming vegetarian and vegan in Australia, and elsewhere in the world (Healey, 2012). However, many vegetarians, especially health-focused vegetarians, revert back to omnivores within a few years (Healey, 2012). Several studies have found that ethically motivated vegetarians have stronger empathetic feelings towards animals that are suffering; in some cases, stronger than those felt towards humans that are suffering (Filippo et al., 2010). Other studies have found that disgust is felt by vegetarians and vegans towards meat (Fessler et al., 2003), but that they are not more sensitive to disgust than omnivores (Haidt, McCauley, & Rozin,1994). A key theoretical question is whether disgust leads to vegetarianism or vice versa. There have been a number of studies to show it is likely that vegetarians and vegans first take a moral stance about animal killings and maltreatment, and further that eating meat is immoral, and instantly or over time develop disgust to reinforce their stance (Rozin, Markwith & Stoess, 1997; Hamilton, 2006). Though Hamilton (2006) found that the relationship between avoidance and aversion is more complex. There is also evidence that evoking disgust can be an effective means of convincing omnivorous people to give up meat; as strong as evoking empathetic feelings through showing images of animals suffering in the production of meat (Palemo-Valex, Tybur & van Vugt, 2018). This suggests that disgust is an effective method of maintaining vegetarianism and veganism, and of reducing motivation to consume meat.

What is disgust?
Darwin described disgust "as something offensive to the taste" The word dis-gust, means "bad taste" in Latin (Rozin & Fallon, 1987). Rozin, Fallon (1987) classify disgust is a basic emotion.

Facial and physiological characteristics of disgust
Facial expression of disgust is characterised by closed nostrils (to avoid a smell) and opened mouth (to expel the revolting food). Human infants and rats distinctively open their mouth when given a bitter taste (Rozin & Fallon, 1987) (Picture) Physiological characteristic of disgust is nausea (to discourage digestion) (Rozin & Fallon, 1987).



Features of disgust

 * 1) a mental state (revulsion-offense-disgust)
 * 2) perception of a possible contamination from the source of disgust
 * 3) feeling of nausea
 * 4) facial expression of disgust
 * 5) rejection of the imagined source of disgust (Rozin, Markwith, and Stoess, 1997)

An evolutionary role of disgust
Curtis (2011) takes the approach that disgust is a system that evolved to avoid infectious diseases. Curtis & de Barra (2018) outline the emerging consensus that disgust evolved in order to enable animals to reduce their risk from diseases. That behaviour is a way of avoiding parasites with, in many cases, limited costs in terms of not being able to eat.

A role of disgust for individuals and societies

 * Disgust causes stress for the person who is caring for the sick and elderly
 * Disgust plays a role in the justice system by helping people to distinguish right from wrong.
 * The abuse of disgust leads to increasing racism amongst groups of people that historically had a high likelihood of coming into contact with diseased individuals (Curtis, 2011)

See more on disgust

Who is a vegetarian and types of vegetarians
The term "vegetarian" can describe a variety of food choices generally including plant food and avoiding all or some animals (Preylo and Arikawa, 2015). Some literature defines vegetarians as never eating meat, poultry or sea food (Preylo and Arikawa, 2015). Other authors consider people as pure vegetarians if they also avoid milk and eggs, and identify the ones who consume mild and eggs as Lacto-Ovo-Vegetarians or Lacto and Ovo Vegetarians if they include only milk or eggs in their diet (Healey, 2012). People who in addition to milk and eggs include sea food identified as Pesco-Vegetarians (or Pescetarians) and people who include chicken are identified as Pollo-Vegetarians). Flexitarians occasionally eat meat (Healey, 2012). Vegans are Pure Vegetarians who also avoid animal derived products, such as wool and leather.

Reasons for becoming a vegetarian
There are many reasons people become vegetarians, including health, moral/ethical, environmental, economical reasons. Most common being a moral or ethical reason and a health reason (Palomo-Vélez∗, Tybur, van Vugt, 2018). Moral vegetarians are concerned about animal welfare. About 150 million land animals are killed in slaughter-houses each day (Zampa, 2019). Animals suffer from anticipation of being killed and from pain and fear during damaging living conditions in factory farms and transportation (Healey, 2012). Moral vegetarians believe that animals sufferings are unnecessary, hence they choose not to participate in inflicting suffering and killing the animals by not consuming the meat (Healey, 2012). Palomo-Velez, Tybur, & van Vugt (2018) gathered the repeated evidence that meat consumption is a major contributor to environmental degradation. Environmental concerns and animal welfare concerns together form moral arguments against meat production (Palomo-Velez, Tybur, & van Vugt, 2018). Fox & Ward (2008) conducted a qualitative study to investigate motivations for becoming vegetarians.

Billy firstly was concerned with animals rights: "I saw the ‘Meet Your Meat’ video and began to research animal rights/ways vegetarianism can help the environment. I realised that I love animals dearly and couldn’t call myself an animal rights supporter and eat meat. It seemed so contradictory. So, one day I just decided to become vegetarian."

Jane and Victoria were exposed to horrifying scenes: "I went vegetarian after dissecting a chicken in seventh grade science class, and noticing that chickens were similar in build up to humans. I went vegan shortly after, because of animal rights, and because I felt that I was being hypocritical to be vegetarian in order to stop animal abuse, but still support it in other major ways. (Jane)

"I became a lacto-ovo vegetarian when I was 13 years old, because I was sitting in my living room eating an Italian sub, and the thought came to me that an animal is not being honoured by sitting between two slices of bread. It made me so very sad that the reason that animal was born was to die. Three months ago I adopted a vegan diet because I think too much about where things come from, and was tired of feeling grossed out every time I ate dairy or eggs. The guilt was too much". (Victoria)

A link between positive attitude for animals and empathy for people
Preylo and Arikawa (2015) used a scale The Pet Attitude Scale-Modified (PAS-M) to examine attitudes towards pets and to some extent towards animals in general and The Interpersonal Reactivity Index (IRI) to measure empathy among 139 USA adults; with seventy two of them being vegetarians, including lacto-ovo, ovo, vegans and fruitarians, and 67 were non-vegetarians. The researchers found a strong correlation between positive attitude for animals and empathy for people. Vegetarian men showed more empathic concerns, high level of perspective taking, were more likely to imagine themselves in someone else’s position and have better attitudes towards pets.

See more on veganism

What role does disgust play in vegetarianism and veganism?
The relationship of disgust and vegetarianism is complex. Disgust is often associated with meat, for example pork to Muslims and Jews. Emotivist's theory suggested vegetarians and vegans are more sensitive to disgust than omnivores, but experimental evidence suggests this is not the case. Some vegetarians and vegans develop disgust towards meat over time that reinforces their moral position of not eating meat, but not all vegetarians and vegans do so.

Moral vegetarianism in understanding a relationship between emotions and moral believes
A relationship between emotions and moral beliefs has been a subject of continuous debate among behavioural scientists (Fessler, Arguello, Mekdara, & Macias, 2003). Researchers use moral vegetarianism in understanding attitudes, values and preferences, specifically, the processes of moral reasoning. Moral vegetarianism can could help understand the process of moral reasoning due to the belief being formed in adulthood rather than in childhood, like most of our beliefs (Fessler, Arguello, Mekdara, Macias, 2003). Rozin & Fallon (1987) and other researchers, particularly Hamilton (2006) observed that disgust is shown when seeing or imagining eating something that is not a food in a particular culture, like imagining eating insects in western cultures, and theorised that avoidance may precede aversion. However, Hamilton’s (2006) study didn’t support that, possibly due to the unrepresentative sample used. Considering a debate about what precedes – avoidance or aversion to meat Hamilton (2006) found that the relationship between avoidance and aversion is more complex. "Yes, I think they are related. The more I think that it’s morally wrong to eat meat the more is seems disgusting to do it."

"Slowly over the course of several years. I only really start to notice it when I pass a butcher’s shop and I think ugghh, no not nice."

Vegetarians seeking to include the other animals as also having a moral right to live
Haidt, McCauley, and Rozin, (1994) examined individual differences and found that all disgust elicitors reminded people of their animal nature and mortality, and they concluded that disgust plays a role in distinguishing themselves from animals. Rosenfeld (2018) identified that the feeling of disgust about meat likely originate from associating meat with its animal origins. Hamilton (2006) argues that the theory is not describing the reactions of vegetarians he interviewed. He gathered qualitative data by interviewing vegetarians and meat-eaters and observed disgust reactions of vegetarians, particularly, moral vegetarians, as not erecting the boundaries between people and animals but seeking to include the other animals as also having a moral right to live and been treated without cruelty.

Also the study by Filippi et al. (2010) involved using fMRI to monitor which parts of the brain were activated in omnivorous, vegetarian and vegan people when they seeing pictures of humans and animals being killed, mutilated, tortured or otherwise harmed. The researchers found that in general terms vegetarians and vegans had consistently greater activation of empathy related areas of the brain when viewing both human and animal suffering pictures, than omnivores. This was associated with reduced activation of the right amygdala which is associated with strongly fearful and threatening (survival instincts) and to a lower extent disgust. The amygdala reduction in vegans and vegetarians may be associated with down-regulation from frontal lobes to manage the emotional response to both human and animal suffering pictures.

Rozin's model: Forming a belief precedes feeling of disgust
Rozin (1997) proposes that forming a belief that eating meat is immoral creates grounds for feeling a disgust, and the disgust then helps to sustain that belief. There is a strong correlation of ethical motive and feeling of disgust. Rozin’s study supported his prediction that long-term moral vegetarians will give multiple reasons to meat avoidance than short-term moral vegetarians and health vegetarians based on people’s tendencies to select and process information that supports their belief. The process of becoming vegetarian involves change from liking meat to disliking it with disliking of meat being a consequence of becoming a vegetarian rather than a cause. Because values are more readily internalised in families then preferences moral vegetarianism is more likely to be past from parents to children then health vegetarianism (Rozin, Markwith, and Stoess, 1997).

As one vegetarian initially motivated by ethical and environmental concerns described her later experience: "'I think, I mean if I sort of walk past the butcher’s or supermarket with raw meat on sale there’s something about it that looks really nasty and because—I think, what I, I think, I regard it as dead—sort of dead flesh really and, which of course it is, and there’s something, you know, it just sort of looks morbid and I think is that purification or?—but I know it’s not. I know it’s not putrefying but it still has that sort of feeling about it and I do sometimes think well could I put that into my mouth and into my body and then I know that I couldn’t do it, because it just would be— it would be just—that physical act would be just too horrible.' (Hamilton, 2006)."

Moral vegetarians found to be more persistent with avoidance of meat then health vegetarians
Rozin, Markwith, and Stoess (1997) tested 3 features (out of 5 listed above) 1) a mental state (revulsion-offense-disgust), 2) perception of a possible contamination from the source of disgust, 3) feeling of nausea, and found that there is a strong correlation between moral vegetarians and a feeling of disgust (based on 2 features, excepting nausea). Contrary to a prediction there is no difference in negative reactions to the taste, smell, texture, or appearance of meat (dislike of the sensory perceptions of meat) between moral and health vegetarians. Rozin, Markwith, and Stoess (1997) also expect that moral vegetarians are more persistent with avoidance of meat then health vegetarians and that it might be due to the recruitment of disgust. Rosenfeld (2018) also identified that ethically motivated vegetarians were more likely to maintain their diet and to dislike the taste and texture of meat and are more likely as a result to abandon meat entirely.

Emotivism's approach
En emotivism's approach based on the arguments that emotions often influence decision making, they questioned a direction of causality – that a moral decision to abstain from meat is motivated by feeling of disgust. Cognitive justification of one’s actions (avoiding meat) then lead to forming a moral stance (Fessler, Arguello, Mekdara, Macias, 2003).

Disgust sensitivity and meat consumption - evidence for Rozin's model
Fessler, Arguello, Mekdara, and Macias (2003) in attempt to test an emotivism’s approach, conducted a survey of 900 people and found that moral and environment vegetarians are no more disgust sensitive then health vegetarians. Their findings were contrary to emotivist's assumptions that moral vegetarians convert as a result of disgust reaction to meat. The findings were supportive of Rozin’s results that moral vegetarians have more disgust to meat then health vegetarians and that disgust is a “consequence of, rather than causal of, the adoption of a moral position.” (Fessler, Arguello, Mekdara, Macias, 2003). The researcher found two factors that correlated with disgust sensitivity - one is that disgust decrease with age, the other is that women were more disgust sensitive than men. As shown in Figure 2, the trend was that individuals who identified ethical reasons also identified environmental reasons. Appearance, smell and taste formed another group.

Figure 2. Relationships between reasons for avoiding meat. Adopted from (Fessler, Arguello, Mekdara, Macias, 2003).

a The percentage of individuals indicating the column reason as their only reason for meat avoidance.

Columns identify individuals on the basis of reasons for meat avoidance. Rows identify the percentage of these individuals that reported the reason in the corresponding column that also reported other reasons.

Using animal welfare and triggering disgust is more effective then promoting health impacts
Palomo-Velez, Tybur, & van Vugt (2018) tested three methods of persuading people to reduce excessive meat consumption; outlining the environmental cost, animal welfare concerns and health impacts in two approaches and seeking to promote meat aversion through triggering disgust as the third approach to persuading people to reduce meat consumption. The study found that using animal welfare and triggering disgust were more effective than seeking to persuade through promoting health impacts. Past studies had found that persuasive arguments put to people on the environmental sustainability and treatment of animal had limited effect in reducing meat consumption, especially in relation to environmental sustainability, with many consumers underestimating the impact of the meat industry. Some studies have identified that the health impacts of excessive meat consumption can be effective in reducing meat consumption, but only when the information is put factually. The study undertook a two stage survey.

Study 1 investigated the effectiveness in changing participants attitude to meat of 328 American participants from reading and recalling essays using the health impact, disgust content and moral/ethical appeals for reducing meat consumption. Study 1 found that the health message was substantially less effective in inducing a changed attitude to meat consumption than either eliciting disgust for meat, or appealing to moral and ethical arguments.

Study 2 sought to separate out within the moral/ethical appeal area, environmental degradation and animal welfare by having 439 American participants read and recall essays on the four topics (health, environment, animal welfare and disgust) areas. The study found that animal welfare concerns led to a changed attitude to meat, while information on environmental degradation did not – leading to the conclusion that within the moral/ethical appeals persuasive text, it was the animal welfare concerns that was leading to a changed attitude to meat.

Study 3 used only the two most effective persuasive arguments; animal welfare and disgust, to identify which had the greater persuasive impact on 407 participants. The two methods of seeking to change attitudes to meat were found to be equally effective, but operate using different modalities; with disgust leading to feelings of nausea and animal welfare arguments leading to feelings of empathy with animals.

Conclusion
While disgust evolved to protect people from harm it is subject to cultural influences, different things can evoke disgust in different people (Curtis, 2011). There have been a number of studies that have shown that disgust is felt by vegetarians and vegans towards meat; and it is likely that some vegetarians and vegans first take a moral stance to not eat meat and over time develop disgust to reinforce their stance of not eating meat (Rozin, Markwith, & Stoess, 1997). Though Hamilton (2006) identified others who believe that it is unethical to kill animals and adopt avoidance of meat out of utilitarian strategy to promote animal welfare and not involve disgust{{gr}. A number of studies have shown that moral vegetarians have stronger empathetic feelings towards animals that are suffering that are suffering (Preylo & Arikawa, 2008; Filippo et al, 2010). And yet other vegetarians initially experience disgust and horror as a result of exposure to scenes of parts of animals, torturing of animals or decaying flesh that reminds them of their our vulnerability and death (Hamilton, 2006).

Nevertheless, there is evidence that evoking disgust can be an effective means of convincing omnivorous people to give up meat; as strong as evoking empathetic feelings through showing images of animals suffering in the production of meat (Palemo-Valex, Tybur & van Vugt, 2018). There is increasing evidence of disgust being developed by vegetarians and vegans to assist in maintaining their moral position (Rosenfeld, 2018) and the powerfulness of disgust in changing people’s attitude towards meat (Palemo-Valex, Tybur & van Vugt, 2018).