mcmifood.pa2 -
Mcmifood.pa2
183. Rozin, P. (2000). Food and eating. Entry in: D. Levinson, J. Ponzetti, & P. Jorgenson (eds.) Encyclopedia of human emotion, Volume 1 (pp.270-273). New York: Macmillan.
Food and eating
3443 words including table, excluding references
Entry for: Encyclopedia of Human Emotions
D. Levinson, J. Ponzetti, & P. Jorgenson (eds.)
MacMillan, New York
Paul Rozin
August 13, 1998
Food and eating, including obtaining and preparing food, are perhaps the major waking activity of humans; more money is spent on food, across all of the cultures in the world than on any other category of expenses. The choice of foods may be the major selective force in animal evolution, accounting for major differences in physical shape, behavior, and the brain. And finally, in human cultural evolution, food and matters pertaining to it are and have been a major source of technologies, ideas, components of rituals and religions, social exchange entities, and metaphor. Many words with broad usages take their origin in food terms, as when we say someone has bad taste, or that we cannot stomach or digest an argument. Two words that have a strong affective tone, bitter and sweet, derive originally from the food domain.
Food and eating (and beverages and drinking) are both fundamental in themselves, and provide a foundation for other activities. This foundation role can be described by the process of preadaptation, the idea that something that evolved for one purpose becomes used for another. The mouth is a fine example of this; it evolved as a route of entry for food (and air), including adaptations for handling food such as teeth and tongue. However, these adaptations became fundamental, later in time, for the expression of speech. The full range of food in human life is beautifully described in Leon Kass’ book, The Hungry Soul.
Food, affect and emotion
The importance of food and eating does not, in itself, justify an entry in an Encylopedia of Human Emotions. But such an entry is justified for the following reasons:
1. Ingestion is moderated by two basic internal states, hunger and thirst. These states have many of the properties of emotions: they relate to issues of pleasure, and they are distinct internal states. They differ from emotions in that they have longer duration and lack a clear expressive component, but it is very likely that the understanding of hunger and thirst would aid our understanding of emotion (and vice versa).
2. Ingestion is a major source of pleasure (and displeasure) for human beings. Any study of affect, the larger category within which emotions fit, would have to include the pleasures of ingestion, and the acquisition of likes and dislikes for foods.
3. There is one basic emotion, disgust, that derives specifically from the ingestive domain, and that is disgust. Although disgust presents as an emotion expressing general offense, there are strong arguments that both in its evolution and development, it begins as a food-related emotion. The entry on disgust treats this issue in more detail.
Studies of food and eating have had two separate aims. The great majority of research deals with how much is eaten; a much smaller part is devoted to what is eaten, that is, food choice. The latter has more to do with emotion, and will receive most attention in this entry.
Food intake: the amount eaten
All animals have some means of regulating their food intake. There are costs to both consuming too little and too much. For humans and virtually all non-grazing animals, eating (and drinking) occurs prinicipally in meals. The major focus of research in this area is the determination of what physiological and psychological factors determine how much is eaten, usually in a meal. The issues of relevance for emotion and affect is that hunger is a substantial predictor of whether we will eat, and how much we will eat. There is reason to believe that the pleasure of eating relates to our physiological state. Michel Cabanac has shown experimentally, for example, that sweet tastes become less pleasant the more satiated we become; he points out that one way our system regulates intake is to modulate the pleasure of eating as a function of our state of need of nutrients. He calls this process, alliesthesia.
Food choice: What is eaten
Affect plays a major role in food choice, since a number of studies have shown that the taste of foods is the best predictor of what foods a person will eat. But there is a deeper way in which affect invades eating. For any person, the world can be divided into the self and everything else. Eating involves taking matter from outside the self and putting it inside the self; this is a very intimate act. It is not surprising that people feel strongly about what they eat. The costs in terms of toxins, micro-organisms, or imbalanced nutrients are high, but the benefits are at least as high; survival is at stake.
The human omnivore.
Humans (and rats, racoons, cockroaches, and many other animals) are omnivores, or more critically, generalists. They eat a wide range of foods; virtually anything that can fit into the mouth is potential food. Generalists have few innate determinants of food choice, simply because it is not easy to predict the nutritive and toxic properties of a potential food on sensory grounds. Usually, one has to try it and see what happens, costly as this might be. There are three documented innate biases in human (and rat) food choice. First, there is an innate tendency to like sweet tastes, which, in nature, are predictive of calorie sources. The long history of sweetness in human culture, from fruit preferences, to cultivation of fruits, to extraction of sugar from fruits, to colonization of the Americas partly to get a source of sugar, to the development of sugar substitutes, is all driven by the innate liking for sugar. There is also an innate tendency to dislike bitter tastes. There is probably an innate tendency to reject very strong tastes, for example highly salty or sour foods. There may also be innate tendencies to like fatty textures, and to dislike oral irritation (as from peppers). Second, there is a suspicion about trying new foods (on account of potential toxicity), but also a conflicting interest in them (on account of their potential as a new nutrient source). Third, there is a special learning mechanism which allows learning about the consequences of ingestion, even when these may occur hours after ingestion.
The human mammal.
Mammals have a unique first food, milk. All mammals make a transition from this first food to an adult diet. For humans and other mammalian omnivores, the transition is from a single food to a very wide range of foods. Weaning is therefore a very challenging event, since it involves forsaking a special food, and replacing it with a wide range of potential foods with a wide range of palatabilities toxicities, and nutritive values. This transition is made under the guidance of parents and other caretakers, and usually consists of a scheduled and graduated introduction of new foods. Determinants of human food choice.
For humans, food choice is accounted for by three types of factors: biological, individual experience, and culture. Culture is the most powerful: if you wanted to predict as much as you could about an individual’s food preferences and attitudes, the best question to ask would be: “what is your culture or ethnic group?”
Culture operates to determine human food choice in ways that have little psychological interest or emotional relevance. Availability is a major condition for consumption of foods, and the consequent exposure is a major determinant of liking. Cultural/economic forces determine what foods a person is exposed to. These same forces determine costs of foods, which also influences exposure and consumption.
Cost and availability aside, it is principally psychological factors represented in the individual (though, of course, heavily influenced by culture) that determine food choice. Human preferences and food attitudes can be framed by a psychological (as opposed to nutritional) taxonomy of foods, developed by Paul Rozin and April Fallon. There appear to be three types of reasons for rejecting or accepting a food: sensory affective, that is, how pleasant a food tastes and smells; anticipated consequences, what the expected consequences are of eating a food; and ideational, what is known about a food (for example, where it comes from, what the nature of it is).
Food rejections can be understood in terms of the selection and interplay of these reasons (Table 1). One category of rejections is called distaste. These are entities rejected because of negative sensory-affective properties, such as lima beans, broccoli, beer, or chili pepper, for those who find these foods distasteful. A second category is danger. These are things rejected primarily because they are believed to be harmful, because of acute or long-term consequences. The emotion of fear is often associated with their consumption. A third category of rejected things -- the largest category--is called inappropriate. These are things that the culture labels as inedible, such as pencils, grass, paper, or cloth. They might taste good, and might be harmless, but they are rejected for ideational reasons. The fourth category is disgust, Disgusting food rejection is also based on ideational, culturally transmitted information, but unlike inappropriates, there is a strong belief that disgusts taste bad and harmful. Unlike the affectively neutral response to inappropriates, the response to disgusts is strongly negative and emotional. Disgust is the most powerful reaction people have to food. Disgusting entities are so powerful that if they touch an otherwise acceptable food, they render it undesirable, disgusting, and inedible (the principle of contamination or contagion).
On the positive side, there are four comparable categories (Table 1). Good taste (acceptance principally because of sensory properties), beneficial (acceptance largely because of consequences), appropriate (acceptance because it is culturally designated as food, or food for a particular occasion), and transvalued (food enchanced because of its prior history). The transvalued category is much weaker and smaller than the disgust category, in most cultures. In Hindu India, food that has been “shared” with the Gods (via donation to the priests in the temple,and then returned, in part), called “prasad,” is an example of transvaluation. Such foods can be positively contaminating.
Unlike the rejection categories, there is little differentiation of associated emotions or affect on the acceptance side: the accompanying psychological state is either pleasure or rather neutral, though a sense of “participation” or elevation may accompany ingestion of transvalued foods.
Table 1
A psychological taxonomy of foods
(modified from Rozin and Fallon, 1987)
Reason / Reject / AcceptDistaste / Danger / Inappropriate / Disgust / Good taste / Bene-ficial / Appro-priate / Trans-valued
Sensoryaffective / __ / ( __ ) / + / ( + )
Conse-
quences / __ / ( __ ) / + / ( + )
Idea-
tional / ( __ ) / __ / __ / + / +
Examp-les / lima beans, hot pepper / allergy food, possible carcin-ogen / paper, grass / worms,
made by
disliked
person / candy,
desserts / bread,
milk / turkey on
Thanks-
giving / prasad in India,
leavings
of gods or
heroes
Affect/
emotion / dis-pleasure / fear / neutral / disgust / pleasure / neutral / pleasure / pleasure elevation
The acquisition of food preferences.
For newborn infants, the only functioning categories are good taste (e.g., sweet) and distaste (e.g., bitter). The full adult categorization, as described in Table 1, is in place by roughly five to eight years of age. Through what processes does this occur?
We are best informed about the distinction between distaste and danger. When ingestion of a food is followed by nausea, it tends to become disliked, that is, a distaste. However, if ingestion of a food is followed by most other negative symptoms (e.g., lower gut pain, skin rash, respiratory distress), the food typically becomes a danger. That is, people reject a food that has caused such symptoms, but it does not usually become a disliked taste. This distinction has also been demonstrated in the laboratory with rats. With respect to affect and emotion, it is notable that dislikes (distastes) and dangers have very different properties, although the outcome (rejection) is the same. It is not at all clear why nausea should produce one type of response (distaste) and most other negative consequences, the other type of response (danger). The nausea-based acquired distaste (often called a conditioned taste aversion), unlike dangers, is not based on a legitimate sense of danger. Even if a person knows that the nausea/upper gastrointestinal illness was not produced by the food, the aversion remains. Thus, people who get nauseous and often vomit after a meal usually develop an aversion to some food in the meal, even if they know that the illness was simply the onset of influenza.
The acquisition of good tastes is more complex and less understood. Mere exposure to a food, in itself, often seems sufficient to produce an acquired like. In addition, the pairing of a food with an already positive event (an already liked food mixed with it, positive regard by a respected person, a pleasant environment), by a process called evaluative conditioning, can lead to acquired likes (or acquired dislikes, if the paired events are negative, as in conditioned taste aversions). Leann Birch has demonstrated that indications of liking by a significant other (peer, older child, teacher, parent) may cause acquisition of liking. The process at work here is not understood. It could be a form of evaluative conditioning. But it also may involve an important instance of communication of affect or emotion. The expressed pleasure by a significant other, on consuming a food, may directly induce a pleasant state in an observer, or it may induce a mimicked positive facial expression. Either of these responses may cause enhancement of liking. Birch has demonstrated, in the laboratory, that efforts by adults to promote liking by emphasizing the beneficial consequences (better health, a specific reward for eating) seem to block the acquisition of liking for the food. It seems that when a child observes respected others enjoying a food, this promotes liking; when she is rewarded for consuming it, this seems to block the acquisition of liking.