traditional factor analysis to structural-causal 8. Cronbach and Meehl, note 7, p. 291 15. For SFA issues in longitudinal data anal- modeling in developmenlal research, m Experi- 9. t^anonical regression models can be written ysis, see I J. McArdle and F Anderson, Lalenl mental Psychology in the ruiure, V. Sarris and A. as a restricted structural equation model where variable growth models in research on aging, in Parducci,'Eds. (Krlbaum, Hillsdale, NJ, 1984); j.J. we eliminate (a) the error variance D^ ^ 0 on the The Handbook of the Psychology of Aging, J.E. Birren McArdle, Principals versus principles in factor latent variable C and (b) the internal validity as- and K,W. Schaie, Eds. (Plenum Press, New York, analysis, Multivariate Behavioral Researth, 25(1), sumptions of uncorrelated residuals among the V" 1990); J.J. McArdle and F. Hamagami, Modehng Sl-87 (1990). variables; see McArdle and Prescott, note 7. incomplete longitudinal and cross-seclional data 2 For path analysis diagrams, see S. VVrighi, 10. For the debate on job performance, see using latent growth structural models. Experimen- On "Path analysis in genetic epidemiology: A cri- M,J. Ree and J.A. Earles, Intelligence is the best tal Aging Research. 18, 145-167 (1992) tique," American journal of Human Genetics. 35, predictor of job performance, Ciirrenl Directions in 16. For further issues about SFA missing-data 757-762 (1982); J.]. McArdle and S.M. Boker, Psi/chakigical Science, 1, 8^^-89 (1992); RJ. Stern- models, see I'.D. Allison, Estimation of linear RAMpath (Eribaum, Hilhdalc, N), 1990). bcrg and R.K. Wagner, The ^.'-ocentnc view of models with incomplete data, m Sociological Meth- 3. I'or classical factor analysis, see J R. Nes- intelligence and job performance is wrong. Cur odology, 1987, C.C. Clogg, Ed. (Jossey-Bass, San seiroade and R. B. Cattell, Handbook of Multivaruitr rent Directions in Psycholo^iictt! Science, 2, 1 4 Francisco, 1987): J.J. McArdle, Structural factor Experimental Psychotogy (Rand MciMally, New (1993). analysis with incomplete data, Multivariate Behav- York, 1988); J.B, Carroll," Human Cognitive Abilities: 11. For the debate on personality factors, see ioral'R.esearch, .-i, 409 454 (1994). A Survey of Pactor-Analytic Studies (Cambridge B. Mershon and R. Gorsuch, Number of factors in 17. For critiques of TEA, see S.J. Gould, 77ji' Universih' Press, New York, 1993), the personality sphere: Does increase in factors Mi^mcasure of Man (W W. Norton, New York, 4. For statistical testing in factor analysis, see increase predictability in real-life criteria? lournal 1981], R.J. Sternberg, Human intelligences The D.N. Lawley and A.E. Maxwell, fuctor Anaiysif^ (!,•= of Personality und Social Psycholo^ii, 55, 67.> .h8(l modo] IS the message. Science, 230, 1111-1118 a Statistical Method (BulterwoTihs, London, 1971); (1988); L.R,' Goldberg, An" alternative "descrip- (1985). M, Browne and R. Cudeck, Alternative ways of tion of personalily": I he Big-Five factor structure, 18. For critiques o! SFA, see N Cliff, Some assessing model fit, m Testin)^ Structural Ltjuatioii journal of t'enaiialittf and Social Psycholo'^y, 59, cautions concerning the application of causal Modeh, K. Bollen and S. Long, Eds. (Sage, New- 1216-1229 (1991)). modeling methods, Multivariate Behavioral Re- bury Park, CA, 1993). 12. For the debate on behavioral genetic mod- search, 18, 115-126 (1983); P. Cohen, J. Cohen, J. 5. Eor power analysis in SFA, see A. Sattora els, see J.J. McArdle and Fi.H Goldsmith. Some Teresi, M. Marchi, and C.N. Vekv., Problems in and W.E. Saris, Power of the likelihood ratio test alternative structural equation models for niulti- the measurement of latent variables in struclural in covariance structure analysis, Psychometrika, variatt? biometric analyses, Bt'havior CJeiit'ticf^, 20, equations causal models. Applied Psychological 50, 83-90 (19«5); M. Sobel and G.W. Bohrnstedt, 569-608 (1990); M.C. Neale and i .R. Cardon, Mcasuwment, 14, 183-196(199(1) Use of null models in evaluating the fit of covari- ,\^dliOiiolo^y for Genetic Studies of Twins and families 19. R.B. Cattell, I'actof Analysis' An Introduc- ance structure models, in SociologKai Methodoiof^y (Kluwer Academic, Boston, 1992), tion and Manual for Ihe Psychologist and Social Sci- 1985, N.B. Tuma, Ed, 0ossey-Bass, San Francis- 13. For current issues in SFA group selection entist (Harper & Brothers, New York, 1952), p. co, 1985). effects, see J,L, Fiorn and J.J, McArdle, A practi- 315 6. For factor analysis of item-level data, see R. cal and theoretical guide to measurement invari- Mislevy, Recent developments in the factor anal- ance in aging research, E.\pt'>imental Aging Re Recommended Reading ysis of categorical variables, journal of Educational search, 18, 117-144 (1992); J.J. McArdle and' R.B. Statistics, II, 3-31 (1986); D.H. Parry and ].]. Cattell, Structural equation models ol factorial in- Boilen, K.A , and Long, J.S. (Eds.). (1993). McArdle, An applied comparison of methods for variance in parallel proportional profiles and ob- Te-'ting Structural Filiation Models (Sage, Newbury least squares factor analysis of dichotomous vari- lique confactor problems, Multit'ariate Bchai'ioral Park, CA). ables. Applied Psychological Meiifiiretnoit, J5(l), 3>- Research, 290), 63-113(1994). Loehlin, J.C. (1992). Latent Variable Models: An 46 (1991) 14. For classical issues of group selection et- Intnhluclion !i< laclor. Path, and Struclura! Analysi> 7. For construct validity and SFA, see L.J. fects, ,see W. Meredith, A method lor studying (Eribaum, Fiillsdale, NJ|. Cronbach and P. Meehl, Construct validity in diflerences between groups, I'syehoiiu'trika. 3

rected mainly by culture-specific Towards a Psychology of Food and traditions. This article deals with Eating: From Motivation to Module to three psychologically significant Model to Marker, Morality, Meaning, Paul Rozin is a Professor of Psy- and Metaphor chology at the University of Pennsylvania. His research inter- Paul Rozin ests are the interaction of biolog- ical, psychological, and cultural influences in relation to food at- titudes and food choice; cultural psychology; and cultural evolu- Each human being experiences from being a source of nutrition tion. Address correspondence to a food trajectory that begins with and sensory pleasure to being a so- Paul Rozin, Department of Psy- one food, milk, and expands to an cial marker, an aesthetic experi- chology, University of Pennsyl- vania, 3815 Walnut St., Philadel- incredibly varied set of foods and ence, a source of meaning and phia, PA 19104-6196; e-mail: preparations, attitudes, and food- metaphor, and, often, a moral en- [email protected]. related rituals. Food progresses tity. These transformations are di-

Published by Cambridge University' Press aspects of human relations with on animal abilities and plasticity of the human brain, body form, food. First, although food relations depend very much on two things: and mind. constitute a major part of human the type of food and the range of Throughout human history, ob- life, they have been virtually ig- food. Specialists, who concentrate taining adequate or pleasing food nored by psychologists. Second, on one kind of food (such as car- has been a major force in deter- biological, psychological, and cul- nivores, insectivores, and some mining both daily events and tural adaptations to food problems fruit and leaf eaters), face few events of great significance. The become the basis (model) for other problems in selecting or balancing linkage between the Eastern and biological and cultural aspects of their diet. Because their range of Western Hemispheres, initiated humans, by the processes of pre- foods is narrow, their food must, by Columbus, had a massive effect adaptation in evolution and acces- of necessity, contain all essential on world politics and daily life. sibility in development, so that elements (the only way for a lion The explorations that led to this food adaptations become general- to be vitamin Bl deficient is for it great "Columbian exchange" were ized to other systems. This pro- to eat vitamin-Bl-deficient zebra). motivated in large part by a desire gression constitutes one of the For such animals, the identifica- for spices. great transformations in human tion of food can be programmed Today, expenditures on food cultural and individual history, genetically. For carnivores, most constitute the largest single cate- and represents the linkage of a ba- psychologically interesting adap- gory for the world at large.^ Food sic biological motivational system tations occur in the search process and drink constitute approximate- to aesthetic, social, and moral as- (because they often eat prey that ly 21% of total expenditures in pects of life. Third, human and an- are widely scattered and hard to Western developed countries, but imal food relations offer special ad- detect) or in the capture of moving more than 50% in many of the vantages for the study of general prey. Substantial social coopera- much more populous Third World processes. tion, motor and tracking skills, countries, notably, India and and elaborate constructions (e.g., China. In both economic and so- spiderwebs) may be involved. cial-moral terms, food is more cen- THE CENTRALITY OF For the generalist species, who tral in the lives of Third World FOOD AND EATING IN eat a wide variety of foods, the than First World people. THE LIFE OF ORGANISMS problem of finding potential food Food is a major source of plea- is often less demanding because sure for almost all humans. In the Food in Animal Life there are so many sources. How- elaborated forms of cuisine, the ever, the identification of food is enjoyment of food has emerged as The search for food, its capture, much more difficult because there an aesthetic pleasure, with food as and its ingestion surely occupy is no simple way that the genes an art form. more time than any other waking can specify what should be eaten, Food plays a central role in de- activity for most animal species. and what should not. With a wide velopment: Nursing and weaning Other than taxonomic status, the range of animals and plants as fair are major features of early life; most informative thing to know game, the possibility of ingesting there is nothing more important in about an animal is the type and toxins is high, as is the possibility early life than learning about what range of food it eats. This informa- (with high amounts of plant foods is edible and what is not. Food is tion predicts types of receptors, in the diet) of eating a nutritional- also a center for parent-child inter- motor skills, plasticity (learning ly unbalanced diet. Hence, great action. Such interactions are not ability), and body form. Food hab- plastic demands are made on such always positive; one of the most its figure pron:iinently in taxo- animals. frequent complaints American nomic categories. The class Mam- parents of toddlers make to their malia is named for its unique Food in Human Life pediatricians is that their toddlers method of feeding young. Families accept only a very narrow range of of mammals, the carnivores and The attainment of a nutrition- foods. insectivores, are named explicitly ally complete and relatively non- Food plays a central role in hu- for their food habits. Shapes of toxic diet has been suggested to be man folk! psychology, too. People birds' bills, as adaptations for han- the principal force in primate evo- in traditional cultures typically be- dling different types of food, are lution.' A switch from forest for- lieve that "you are what you eat." central in bird classification and aging to a savannah life that in- They put forth the very reasonable bird identification. cluded hunting has been invoked suggestion, in accordance with Explicit demands made by food in many accounts of the evolution most experiences in the world.

Copyright '•: 1996 American Psychological Societv that when food and food con- role in daily life and thought— may subsequently appear in other sumer "mix," the consumer takes have almost completely escaped domains, by the processes of on properties of the ingested the interest of academic psychol- preadaptation in biological or cul- food."^ Thus, eating owls improves ogy. Current psychology journals tural evolution and increased ac- night vision, eating lions fosters and textbooks pay almost no atten- cessibility in development. bravery, eating a fast-growing tion to what humans or animals Ernst Mayr*" has invoked the plant promotes growth, eating eat. The only food issue given se- process of preadaptation as a prin- one's friends' food promotes one's rious attention is how much hu- cipal account for major evolution- well-being, and eating one's ene- mans or animals eat. ary changes, such as the evolution mies' foods dims one's prospects. Consider some major psychol- of complex structures. Preadapta- There is evidence suggesting the ogy journals that include a signifi- tion is the engagement of a sys- existence of an implicit belief in cant focus on human affairs and tem, process, or structure in a "you are what you eat" in edu- might be expected to pay some at- functional system other than the cated Westerners.'' tention to human food choice: De- one it was originally evolved for. The social roles of food are velopmental Psychology, the journal In this manner, an existing struc- particularly clear in immigrant of Abnormal Psychology, the Journal ture may be co-opted for a new groups, who seem to retain their of Personality and Social Psychology, purpose, avoiding the necessity of ethnic identity through food long Psychological Bulletin, Psychological a new structure evolving by a after they have become assimilated Review, and Psychological Science. gradual process in which each in- in most other ways. Similarly, In 1993, there were 497 articles termediate form is either neutral or food habits and taboos frequently published in these journals. Only adaptive in itself. The preadapted serve as markers for particular cul- 3 have any relevance to human structure may or may not continue turally defined groups of people. food selection, and none focused to function in its original context. The sharing of food is a major fea- on it. In principle, the preadapted struc- ture of the expression of solidarity, In the most recent editions of ture need not have been specifi- just as avoidance of food sharing is eight leading introductory psy- cally selected for its original func- an expression of social distance, chology textbooks, with a median tion, but may be a structure of especially in Hindu India."* Even in length of 668 pages, the median neutral adaptive value. American culture, sharing of food number of pages devoted to what The middle ear bones of mam- is an indicator of close relation- humans eat and why is 0.4 pages. mals, which originated from parts ships. In comparison, medians of 8 pages of the reptile jaw, are an example Food is often central in religious are devoted to hunger and 12.5 to of a preadaptation that ceased to systems. The eating of an apple is sleep. function in its original context. The the core of the Adam and Eve It is not the purpose of this ar- human mouth is an example of a story. In the Hindu religion, ritual ticle to explain why psychology preadaptation that has maintained purity is maintained, in large part, has ignored food selection, nor is its original function. The mouth by food offerings to the deities and there a clear answer. However, evolved originally as a way to in- the avoidance of foods that are one contributing factor may be the corporate foods, and one can eas- polluted by virtue of their nature strong emphasis on process, and ily account for the presence of or their previous human contacts. general processes in particular, in tongue and teeth in this manner. Eating is the principal mode of psychology. Food is not uniquely With the evolution of an elaborate material transaction between the ignored; major domains of human linguistic communication system world and the person. Given the activity, including religion, sports, in humans, features of the mouth, way that food has permeated hu- and other leisure activities, receive such as tongue and teeth, served man life, it is not surprising that minimal attention as well. as preadaptations for articulatory among the Hua of Papua New devices. They have a critical func- Guinea, the word for everything is tion in pronunciation of conso- "that which can be eaten, and that FOOD ADAPTATIONS AS nants. A SOURCE OF which cannot."^ f extended the idea of preadap- GENERAI ADAPTATIONS tation into the developmental Food and Psychology Preadaptation and realm, using the term access. Sys- Despite these facts about the Increased Accessibility tems evolved to handle specific centrality of food in human life, problems in the world can be ac- the foods that humans eat—the se- Adaptations that originate to cessed in development to handle lection of those foods and their solve problems in food selection other types of problems. Thus,

Published by Cambridge University Press some abilities move from being do- big enough to haul large loads It is quite likely that some plastic main-specific to being more do- (trucks); one can engineer this re- abilities that originated in learning main-general during development sult once the possibility is realized. about foods were eventually ac- and as a result of education. For Similarly, a computer can arise cessed in other systems. In the example, Siegal* proposed that from a combination of calcula- framework of modularity, food ad- reasoning ability appears first in tor and typewriter without any aptation modules may presage the the food system (with respect to chance linkage of the two. development or evolution of more avoiding contamination), and later There are a number of interest- generaiiy useful systems. in other areas. I^ proposed that the ing cultural preadaptations in the The cultural evolution of disgust "ear/mouth route," the machinery food domain. Food itself, primari- illustrates cultural preadaptation. that evolved specifically for com- ly an instrument of nutrition and prehending and producing speech pleasure in animal life, becomes The Cultural Evolution by segmenting it into significant utilized by humans as part of an of Disgust units of sound (phonological seg- aesthetic system (cuisine), a social mentation), becomes co-opted in marker (e.g., in ethnic cuisines), According to the analysis I have reading systems that etnploy al- and a moral instrument (as in constructed with my colleagues phabets. Thus, children's realiza- Hindu culture). Food terms take April Fallon, Jonathan Haidt, tion that the word bat has three on new meanings as sytnbols to Clark McCauley, and Sumio sounds, an essential accomplish- represent gender and other impor- Imada^^'^^ disgust originates as a ment for comprehending alpha- tant issues. Food concepts come to rejection response to bad-tasting betic systems, involves some type be used as metaphors (a form of foods and expands, in humans, of access to this phonological seg- preadaptation) for other matters, into a general system for putting mentation machinery. as in the generic uses of the words out of one's mind anything that Preadaptation is probably most bitter and sweet, and in such formu- one's culture considers offensive. common in cultural evolution be- lations as "digesting the facts," be- Disgust evolves culturally and de- cause preadaptation can occur in ing "unable to swallow" a particu- velops from a system to protect the biological evolution only at a point lar conception, reading the "meaty body from harm to a system to where the new functional system part" of a paper, "biting off more protect the soul from harm. has some "contact" with the orig- than you can chew," or "spoon- The proposed pathway is illus- inal structure.^ Jaw bones can be feeding" students.^*' trated in Table 1. The origin of hu- selected for sound transmission Learning about what is edible man disgust is in the rejection- only at a point where they already and what is not is of absolutely withdrawal response to baci tastes, have some minimal value in this fundamental importance for gen- observed in many mammals and regard. However, in cultural evo- eralist animals. Unlike many other in the human infant. This re- lution, human realization of the systems, such as mate identifica- sponse is characterized, facially, value of a part of one system in tion, food selection is what Mayr'^ principally by the gape response, another system is sufficient to es- called an open system, that is, a which has the function of causing tablish the link. One does not have system in which one cannot genet- what is in the mouth to dribble to wait for cars to gradually get ically prespecify critical categories. out, and is elicited by innately bad

Table 1. Proposed pathway of expansion of disgust atid disgust eliators^^

Disgust stage Interpersonal Characteristic Distaste Core Animal origin contamination Moral Function Protect body Protect body and Protect body and Protect body, soul, Protect social soul soul and social order order Elicitors Bad tastes Food and eating, Sex, death, hygiene, Direct and indirect Certain moral body products, envelope violations contact with offenses animals strangers or undesirables

Copyright © 19% American Psychological Socif?h' tastes (e.g., bitter substances) and eating animals, by the "you are nism, to keep human animalness acquired bad tastes. My colleagues what you eat" principle, they blur out of awareness. and I call this entire set of reactions the distinction between humans We have developed a disgust- to bad tastes the distaste system, to and animals, and become animal- sensitivity scale.'^ Analysis of re- distinguish it from disgust. like. The contamination principle sults from this scale suggests that Disgust is one of the basic emo- may appear first in disgust to ot the eliciting categories, contact tions. It is characterized on the re- foods, and is perhaps the original with death may be the best predic- sponse side by a behavioral with- manifestation of the sympathetic tor of total disgust sensitivity. drawal; a facial expression in- magical law of contagion: once in (Two of the five items that best cluding gape, wrinkling of the contact, always in contact. When predict the total score on the dis- nose, and raising of the upper lip; one's mashed potatoes are briefly gust scale are "It would bother me a physiological manifestation of contacted by an earthworm, tremendously to touch a dead nausea; and a sense of revulsion. "wormness" enters into them, they body," which is answered "true" There has been very little study of are permanently "wormed."''' or "false," and "Your friend's pet this emotion (the two classical con- Body wastes, particularly feces, cat dies, and you have to pick up tributions are by Darwin^* and An- may constitute the strongest elici- the body with your bare hands," gyal^^). We believe this emotion tors of core disgust, and disgust at which calls for a response of "not derives from the initial distaste re- feces seems to be the universal dis- disgusting at all," "slightly dis- sponse, and shares with it many gust. Thus, the elicitors of core dis- gusting," or "very disgusting.") facial features, nausea, with- gust are animals, food, and partic- We interpret this finding to mean drawal, and revulsion—in short, ularly body wastes. that the most threatening aspect of all of the output features. How- Core disgust is qualitatively dif- humans' animalness is their mor- ever, the category of elicitors and ferent, in terms of meaning, from tality,''' and that disgust serves as the meaning of the system are distaste. Disgusting items need a defense against pondering mor- qualitatively changed. not have negative sensory proper- tality. Animal-origin disgust In the first stage of this cultural ties. Distasteful substances typi- shares the disgust output system evolution and development, the cally do not have contamination (nausea, withdrawal, revulsion, food focus remains, but the elicit- properties, whereas disgusting facial expression). ing category becomes potential in- substances do. In short, we claim There are two other common gesta that are offensive. That is, re- that in terms of elicitors and mean- categories of elicitors of disgust. jection is based on the idea of what ing, disgust is not an extension of We have no idea of their order in the food is and on its nature rather distaste, but an entirely new cate- development or cultural evolu- than on its sensory properties. In gory of ideationally based, con- tion, but they are clearly tied into accord with Angyal, we define this tamination-sensitive revulsion or the same system. One is interper- type of disgust, which we call core withdrawal. sonal disgust, in which the elicitors disgust, as "revulsion at the pros- When we ask Americans or lap- are contact with strangers or unde- pect of (oral) incorporation of an anese what they find most disgust- sirable others. This kind of disgust offensive substance. This sub- ing, only about 25% of the re- accounts for the aversion that most stance has contamination proper- sponses fall into the animal-food- Americans have to wearing cloth- ties. It is so negative that if it body wastes domain. Many of the ing previously worn by undesir- touches an otherwise acceptable other responses invoke poor hy- able people (e.g., personal ene- food, it renders that food unac- giene, body envelope violations mies, morally tainted or unsavory ceptable (contamination)."'^ (e.g., gore), inappropriate sex, or people) or to consuming food pre- Core disgust, in our view, is death. We believe that these elicit- viously bitten by such people. In- based on the "you are what you ing categories, along with the core terpersonal disgust is more highly eat" principle, which we believe is disgust elicitors, have in common developed in other cultures. For operative in modern Western cul- that they refer to properties hu- example, in Hindu India, the ac- tures, as well as traditional cul- mans share with animals. We companying sense of pollution is tures.^ The idea is that if you eat therefore conceive of this wider highly salient and forms a major something offensive, then you will category of disgust as animal-origin part of the psychological basis for become offensive. We believe the disgust. It involves a withdrawal maintenance of the caste system. basic eliciting category for core dis- from reminders of humans' link- A final category of disgust is gust is foods of animal origin. Al- age with animals, an origin people moral. Certain types of moral of- though humans want to distin- would prefer to forget. Disgust fenses are often characterized as guish themselves from animals, by functions like a defense mecha- disgusting. Shweder and his col-

Published by Cambridj;^ University Press leagues^" have suggested that appeal because of some specific of children are central concerns of there are three basic moral systems properties of the food system. developmental psychology. It has in the world. One has to do with Food-related behavior is extremely been shown, using food and other rights violations, one with com- frequent and renewable, and often domains, that within-culture vari- munity and social hierarchy viola- involves complex systems and ation in preferences of children is tions, and one with purity viola- plasticity. For the case of humans, only very weakly related to paren- tions. We propose that disgust is food-related behavior is generally tal preferences. I have labeled this the emotion linked to moral viola- easy to observe, and food is a sub- the/flm/7y paradox.^'^ However, par- tions in the purity domain. Among ject that most people will discuss ent-child correlations for values the elite in modern Western cul- readily. (e.g., attitudes to abortion) that tures, disgust is not a moral emo- It is no accident that the classic vary within culture show much tion because purity violations work on learning, in the laborato- stronger parent-child correla- (such as eating cockroaches) are ries of Pavlov, Skinner, and Thorn- tions.^•^'^•"' Food is a particularly apt not considered immoral. How- dike, used food reinforcement. domain in which to explore critical ever, in many traditional cultures More recent research on learning issues here because attitudes to and among less well educated peo- has extensively used conditioned foods include both preferences ple in Western developed cul- taste aversions as a paradigm, and and values. For example, liking for tures,^^ purity violations (such as has also explored foraging for meat is generally a preference is- eating dog meat or using an old food. sue, but it becomes a moral issue national flag as a cleaning rag) are Whether or not the food system for some vegetarians. The process considered immoral. Indeed, al- is the origin of a particular feature of acquisition of moral values is though rights violations may be or process, it is often convenient to well exemplified in the food do- the exclusive form of morali- study that feature or process in the main, especially with respect to ty among educated people in food system. Some examples re- the moralization of tobacco smok- Western cultures, community- lated to some basic issues in psy- ing and meat eating in America in hierarchy and purity violations chology are described briefly in recent decades.^^ constitute a major part of morality this section. in Hindu India.^" The Study of Conflict: We have mapped a hypothetical Internalization sequence of elaboration of disgust Rational-Irrational Oppositions (Table 1), holding that this se- and Ambivalence quence occurs in both develop- Surprisingly little is known about how humans come to Uke ment (by increased accessibility) The conflicts between different {or dislike) things such as work, and cultural evolution (by pread- parts of the person have been cen- sports teams, pets, foods, music, aptation). Disgust becomes a ma- tral to psychology since Freud. and stamp collecting. To some ex- jor route to socialization; if you The food domain is of special in- tent, research in this area involves want people to refrain from some terest in this regard because hu- understanding the process of in- activity, make it disgusting. Note man intelligence is highly devel- ternalization, that is, how people that the contamination property of oped in this domain,^ but at the get to like things for their intrinsic disgust expands as the categories same time people have strong feel- value, rather than as means to an of elicitors expand, so that, in both ings related to the entrance of sub- end.^^-^^ Likes and dislikes for India and the United States, wear- stances into the body via the foods develop very frequently and ing clothes previously worn by un- mouth. The power of disgust and can serve as a model system for desirable people or making physi- contagion as deep feelings and study. Conditioned taste aver- cal contact (e.g., via clothing) with cognitions has already been dis- sions in animals and humans are healthy but morally tainted people cussed. Because it is easy to talk to probably the best documented and {e.g., murderers) is both disgust- people about food, the food do- understood example of a change in ing and contaminating. main is a good place to explore liking for any entity. conflicts between feelings and cog- nitions. Thus, people will openly FOOD AS A CONVENIENT Transmission of Preferences admit to their irrationality in not MODEL SYSTEM and Values wanting to eat a sterilized cock- roach, but still acknowledge these The study of food-related be- The mechanisms of parental in- feelings. Finally, conflict as ex- havior in animals and humans has fluence on preferences and values pressed in ambivalence is quintes-

Copyright V 1996 American Psychological Society sentially illustrated in attitudes to emotion. There is something novelties, in Fvolution After Darwin: Vol. 1. Tht: tvolutwn of Life, S, Tax, Ed, (University of Chi- meat. High appeal to the human amusing, at the same time as it is cago Press, Chicago, 19fi(l), palate and excellent short-term nu- negative, about disgust. It is prob- 7. P, Rozin, The evolution of intelligence and access to the cognitive unconscious, in Progress ni tritional value are pitted against ably the only way to reliably elicit Psythobiokigy and Phi/^iological Psychology. Vol. 6, concerns about long-term health strong negative affect ethically in ),N. Sprague and A.N, Epstein, Eds. (Academic Press, New York, 1976). risks and the immoral treatment of the laboratory. 8. M.S, Siegal, Becoming mindful of food. animals. Current Directions in Psychological Science. 4. 177- 181 (1995), 9. VV.J. Bock, Preadaptation and multiple ev- olutionary pathways. Evolution, 13. 194-211 Playing With the Limits and CONCLUSIONS (1959). Benign Masochism 10. C. Lakcfl" and M. Johnson, Metaphors V\V Live Bl/ (University of Chicago Press, Chicago, In this broad survey, I have at- 1980), tempted to engage the interest of 11 E. Mayr, Behavior programs and evolu- Humans are unique among an- tionary strategies, American Scientist, 62, 650-659 imals in enjoying activities that psychologists, with the aim of (1974). both conveying something about 12 P. Rozin and A.E, Fallon, A perspoclive produce innately negative feelings on disgust. Psychological Review, 94. 23-41 (1987). or emotions (e,g., movies eliciting the important domain of food se- 13. P. Rozin, j. Haidt, and C.R, McCauley, sadness), activities that induce fear lection in humans and encourag- Disgust, in Handbook of Eniolioii'^, M, Lewis and ) M. Haviland, Eds. (Guilford Press, New York, (e.g., riding roller coasters), and ing more research in this area. If 1993). activities that produce pain (e.g., we are what we eat, then we 14 C.R, Darwin, The Lxpression of Emotions in Man and Animals (University of Chicago Press, smoking cigarettes, eating chili should certainly want to know Chicago, 1965) (Original work published 1872), peppers, taking hot baths). I have what we eat and why. There is no 15. A Angyal, Disgust and related aversions, journal of Abnormal and Social Psychology. 36, 393- suggested^' that such preferences domain where there is a richer in- 412 (1941), represent a benign masochism, a teraction of basic biological urges, 16 Rozin and Fallon, note 12, p, 23. sort of pleasure at the mastery of cultural values, and individual 17. For a review of the literature on conlagion, see P, Rozin and C, Nemeroff, The laws of sym- mind over body. For the case of abilities and experiences. There is pathetic magic: Psychological analysis ol similar- innately aversive foods (or the rec- no area where the progression ity and contagion, in Cultural Psychology: Lssays on Comparative Human Development, J. Stigler, R.A. reational elicitation of disgust), from motivation to module to Shweder, and G. Herdt, Kds (Cambridge Univer- there may be pleasure resulting model to marker, morality, mean- sity Press, Cambridge, England, 1990), ' 18. ]. Haidt, C.R. McCauley, and P. Rozin, A from the fact that the body is sig- ing, and metaphor is more appar- scale to measure disgust sensitivity. Personality naling rejection, but the person ent. and Individual Difftrences. 16. 701-713 (1994), 19, E, Becker, The Denial of Dratli (Free Press, knows there is no real threat (ob- New York, 1973), viously the case in roller-coaster Acknowledgments—Much of the re- 20, R.A. Shweder, N C. Much, M, Mahapa- riding). The existence of prefer- search described in this article, along tra, and L, Park, The "big three" of morality (au- with the writing of this article, was sup- tonomy, community and divinity), and the "big ences for innately unpalatable ported by grants to Paul Rozin from the three" explanahons of suffering, in Morality and foods in all cultures offers wide Whitehall Foundation and the John D, Health, A. Brandt and P. Rozin, Eds, (Routledge, and Catherine T. MacArthur Founda- New York, in press) opportunities for research. 21, |, Haidt, S.H Roller, and M.G, Dias, Af- tion network on health-related behav- fect, culture and morality, or Is it wrong to eat iors. Thanks to Monica Schindlinger your dog? Journal of Personality and Social Psychol- Rozin for comments on the manuscript. ogy, 65, 613-628 (1993), Disgust as an Ethical and 22, L.L, Birch, Children's food preferences: Convenient Way to Study Affect Developmental patterns and environmental influ- ences, in Annals of Child Development, Vol, 4, G. Whitehurst and R. Vasta, Eds, (|AI, Greenwich, Notes CT, 1987). The laudable rise in concern for 23, P. Rozin, Acquisition of stable lood pref- the mental health of experimental "1. K, Millon, Diet and primate evolution. Sci- erences. Nutrition Reviews. 48, 1(16-113 (1990). human subjects has placed limits entific American, pp. 86-93 (August 1993), 24, P, Rozin, Eamily resemblance m food and 2. R,J, Samuehon, E"d., 'Ihe }:cnnomist Book of other domains: The family paradox and the role on the use of aversive stimuli in Vita! World Statistics {Random House, New York, of parental congruence, Appetite, 16, 93-102 experimental studies. Disgust 1990), (1991). 3. C Nemeroff and P, Rozin, "You are whai 25, L.L, Cavalli-Sforza, M.W. Feldman, K.H. holds promise as a strongly nega- you eat:" Applying the den^and free "impres- Chen, and S,Ivl. Dornbusch, Theory and observa- tive system that can be elicited sions" technique to an unacknowledged belief, tion in cultural transmission. Science. 218. 19-27 F.thos: The journal of Psychologicul Anthwpohgt/, 17, (1982), with ease in the laboratory. For 50-69(1989). 26, P. Rozin, Moralization, in Moralily and fascinating and not fully under- 4. A, Appadurai, Gastro-politics in Hindu Health, A. Brandt and P, Rozin, Eds. (Routledge, stood reasons, neither individuals South Asia, American Ethnologist, S, 494-511 New York, m press), (1981), 27, P, Rozin, Psychoiogicai, biological and nor (consequently) human subject 5. A.S. Meigs, Food. Sex, and Pollution: A New cultural perspectives on the use of chili pepper by protection committees seem con- Guinea Religion (Rutgers University Press, New humans, in Chemical Irritation, B. Green, R, Ma- Brunswick, N], 1984), son, and M,R, Kare, Eds, (Marcel Dekker, New cerned about elicitation of this 6. E. MAVT, The emergence oi evolutionarv' York, 1990).

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