Why disgust matters

Philosophical Transactions of the Royal Society B: Biological Sciences

Volumn 366, Issue 1583, 2011, Pages 3478-3490

  Curtis, Valerie ^a  

^a LONDON SCHOOL OF HYGIENE AND TROPICAL MEDICINE   (United Kingdom)

Author keywords

Behaviour; Disease; Disgust; Evolution; Obsessive compulsive disorder

Indexed keywords

AVOIDANCE REACTION; BEHAVIOR; BRAIN; DIARRHEAL DISEASE; DISEASE RESISTANCE; EVOLUTIONARY BIOLOGY; HEALTH CARE; INFECTIOUS DISEASE; MENTAL HEALTH; NEUROLOGY; SMOKING;

FISTULA;

EID: 80055100263     PISSN: 09628436     EISSN: 14712970     Source Type: Journal    
DOI: 10.1098/rstb.2011.0165     Document Type: Article

References (130)

1. Curtis, V. & Biran, A. 2001 Dirt, disgust, and disease: is hygiene in our genes? Perspect. Biol. Med. 44, 17-31. (doi:10.1353/pbm.2001.0001)
2. Curtis, V., Aunger, R. & Rabie, T. 2004 Evidence that disgust evolved to protect from risk of disease. Proc. R. Soc. B 271(Suppl. 4), S131-S133. (doi:10. 1098/rsbl.2003.0144)
3. Fessler, D. M. T., Eng, S. J. & Navarrete, C. D. 2005 Elevated disgust sensitivity in the first trimester of pregnancy: evidence supporting the compensatory prophylaxis hypothesis. Evol. Hum. Behav. 26, 344-351. (doi:10. 1016/j.evolhumbehav.2004.12.001)
4. Schaller, M. & Duncan, L. A. 2007 The behavioral immune system: its evolution and social psychological implications. In Evolution of the social mind: evolutionary psychology and social cognition (eds J. P. Forgas, M. G. Haselton & W. von Hippel), pp. 293-307. New York, NY: Psychological Press.
5. Oaten, M., Stevenson, R. J. & Case, T. I. 2009 Disgust as a disease-avoidance mechanism. Psychol. Bull. 135, 303-321. (doi:10.1037/a0014823)
6. Tybur, J. M., Lieberman, D. & Griskevicius, V. 2009 Microbes, mating, and morality: individual differences in three functional domains of disgust. J. Pers. Soc. Psychol. 97, 103. (doi:10.1037/a0015474)
7. Curtis, V., de Barra, M. & Aunger, R. 2011 Disgust as an adaptive system for disease avoidance behaviour. Phil. Trans. R. Soc. B 366, 389-401. (doi:10.1098/ rstb.2010.0117)
8. Haidt, J., Rozin, P., McCauley, C. & Imada, S. 1997 Body, psyche, and culture: the relationship of disgust to morality. Psychol. Develop. Soc. 9, 107-131. (doi:10. 1177/097133369700900105)
9. Chapman, H., Kim, D., Susskind, J. & Anderson, A. 2009 In bad taste: evidence for the oral origins of moral disgust. Science 323, 1222-1226. (doi:10.1126/ science.1165565)
10. Phillips, M. L., Senior, C., Fahy, T. & David, A. S. 1998 Disgust-the forgotten emotion of psychiatry. Br. J. Psychiatry 172, 373-375. (doi:10.1192/bjp.172.5.373)
11. Rozin, P., Haidt, J. & McCauley, C. 2008 Disgust. In Handbook of emotions (eds M. Lewis, J. Haviland Jones & L. Feldman-Barrett), pp. 757-776, 3rd edn. New York, NY: Guilford Press.
12. Fessler, D. M. T. & Navarrete, C. D. 2005 The effect of age on death disgust: challenges to terror management perspectives. Evol. Psychol. 3, 279-296.
13. Douglas, M. 1966 Purity and danger: an analysis of the concepts of pollution and taboo. London, UK: Routledge and Kegan Paul.
14. Miller, W. I. 1997 The anatomy of disgust. Cambridge, MA: Harvard University Press.
15. Sperber, D. 1996 Explaining culture: a naturalistic approach. Oxford, UK: Blackwell.
16. Hotez, P. J. et al. 2006 Helminth infections: soil-transmitted helminth infections and schistosomiasis. In Disease control priorities in developing countries, pp. 467-482, 2nd edn. New York, NY: Oxford University Press.
17. Heymann, D. 2008 Control of communicable diseases manual, 19th edn. Washington, DC: American Public Health Association.
18. Cochran, G. M., Ewald, P. W. & Cochran, K. D. 2000 Infectious causation of disease: an evolutionary perspective. Perspect. Biol. Med. 43, 406-448.
19. Curtis, V. 2007 Dirt, disgust and disease: a natural history of hygiene. J. Epidemiol. Commun. Health 61, 660-664. (doi:10.1136/jech.2007.062380)
20. Jefferson, T., Foxlee, R., Mar, C. D., Dooley, L., Ferroni, E., Hewak, B., Prabhala, A., Nair, S. & Rivetti, A. 2008 Physical interventions to interrupt or reduce the spread of respiratory viruses: systematic review. Br. Med. J. 336, 77-80. (doi:10.1136/bmj.39393.510347.BE)
21. Stevenson, R. J., Case, T. I. & Oaten, M. J. 2009 Frequency and recency of infection and their relationship with disgust and contamination sensitivity. Evol. Hum. Behav. 30, 363-368. (doi:10.1016/j.evolhumbehav. 2009.02.005)
22. Donovan, B. 2000 The repertoire of human efforts to avoid sexually transmissible diseases: past and present. Part 1: strategies used before or instead of sex. Sex. Transm. Infect. 76, 7-12. (doi:10.1136/sti.76.1.7)
23. Diamond, J. 1997 Guns, germs and steel. London, UK: Jonathan Cape.
24. Curtis, V. 2007 A natural history of hygiene. Can. J. Infect. Dis. Med. Microbiol. 18, 11-14.
25. Boschi-Pinto, C., Velebit, L. & Shibuya, K. 2008 Estimating child mortality due to diarrhoea in developing countries: a meta-analysis review. Bull. WHO 9, 710-717.
26. Curtis, V. A., Cairncross, S. & Yonli, R. 2000 Domestic hygiene and diarrhoea, pinpointing the problem. Trop. Med. Int. Health 5, 22-32. (doi:10.1046/j.1365-3156. 2000.00512.x)
27. Curtis, V. & Cairncross, S. 2003 Effect of washing hands with soap on diarrhoea risk in the community: a systematic review. Lancet Infect. Dis. 3, 275-281. (doi:10.1016/S1473-3099(03)00606-6)
28. Rabie, T. & Curtis, V. 2006 Handwashing and risk of respiratory infections: a quantitative systematic review. Trop. Med. Int. Health 11, 269-278. (doi:10.1111/j. 1365-3156.2006.01568.x)
29. Emerson, P. M., Cairncross, S., Bailey, R. L. & Mabey, D. C. W. 2000 A review of the evidence for the 'F' and 'E' components of the SAFE strategy for trachoma control. Trop. Med. Int. Health 5, 515-527. (doi:10.1046/j. 1365-3156.2000.00603.x)
30. Huang, D. & Zhou, J. 2007 Effect of intensive handwashing in the prevention of diarrhoeal illness among patients with AIDS: a randomized controlled study. J. Med. Microbiol. 56, 659-663. (doi:10.1099/jmm.0. 46867-0)
31. Humphrey, J. H. 2009 Child undernutrition, tropical enteropathy, toilets, and handwashing. Lancet 374, 1032-1035. (doi:10.1016/S0140-6736(09)60950-8)
32. Curtis, V., Danquah, L. & Aunger, R. 2009 Planned, motivated and habitual hygiene behaviour: an eleven country review. Health Educ. Res. 24, 655-673. (doi:10.1093/her/cyp002)
33. Curtis, V. A., Biran, A., Deverell, K., Hughes, C., Bellamy, K. & Drasar, B. 2003 Hygiene in the home: relating bugs to behaviour. Soc. Sci. Med. 57, 657-672. (doi:10.1016/S0277-9536(02)00409-4)
34. Judah, G., Aunger, R., Schmidt, W. P., Michie, S., Granger, S. & Curtis, V. 2009 Experimental pretesting of hand-washing interventions in a natural setting. Am. J. Public Health 99, S405-S411. (doi:10.2105/ AJPH.2009.164160)
35. Lintas, L. 2004 Truly clean-mothers. See http://www.globalhandwashing.org/multimedia.
36. Scott, B., Schmidt, W., Aunger, R., Garbrah-Aidoo, N. & Animashaun, R. 2007 Marketing hygiene behaviours: the impact of different communications channels on reported handwashing behaviour of women in Ghana. Health Educ. Res. 22, 225-233.
37. Curtis, V., Kanki, B., Cousens, S., Diallo, I., Kpozehouen, A., Sangaré, M. & Nikiema, M. 2001 Evidence for behaviour change following a hygiene promotion programme in West Africa. Bull. WHO 79, 518-526.
38. Dubner, S. J. & Levitt, S. D. 2006 Selling soap: the Petri-dish screen saver. The New York Times, 24 September 2004.
39. Drummond, R. P., Stevenson, R., Case, T. & Oaten, M. 2009 Can the emotion of disgust be harnessed to promote hand hygiene? Experimental and field-based tests. Soc. Sci. Med. 68, 1006-1012. (doi:10.1016/j. socscimed.2009.01.013)
40. NHS 2009 Important information about swine flu. London, UK: NHS Scotland, NHS Wales, Department of Health, Social Services and Public Safety.]
41. Stevenson, R. J., Oaten, M. J., Case, T. I., Repacholi, B. M. & Wagland, P. 2010 Children's response to adult disgust elicitors: development and acquisition. Dev. Psychol. 46, 165-177. (doi:10.1037/a0016692)
42. Curtis, V., de Barra, M. & Aunger, R. 2011 Disgust as an adaptive system for disease avoidance behaviour. Phil. Trans. R. Soc. B 366, 1320. (doi:10.1098/rstb. 2010.0002)
43. McNally, R. J. 1987 Preparedness and phobias. Psychol. Bull. 29, 91-94.
44. Ohman, A. & Mineka, S. 2001 Fears, phobias, and preparedness: toward an evolved module of fear and fear learning. Psychol. Rev. 108, 483-522. (doi:10.1037/ 0033-295X.108.3.483)
45. Seligman, M. E. P. 1971 Phobias and preparedness. Behav. Ther. 2, 307-320. (doi:10.1016/S0005-7894(71) 80064-3)
46. Florida Department of Health 2009 Talk to the fifth guy. See http://www.5thguy.com/coveringcoughs.htm
47. Schmidt, W. & Curtis, V. 2011 Hand and respiratory hygiene for influenza control in the general population. London, UK: London School of Hygiene and Tropical Medicine.
48. Nesse, R. M. 2005 Natural selection and the regulation of defenses: a signal detection analysis of the smoke detector principle. Evol. Hum. Behav. 26, 88-105. (doi:10.1016/j.evolhumbehav.2004.08.002)
49. Haselton, M. G. & Nettle, D. 2006 The paranoid optimist: an integrative evolutionary model of cognitive biases. Pers. Soc. Psychol. Rev. 10, 47-66. (doi:10. 1207/s15327957pspr1001_3)
50. Knowles, T., Moody, R. & McEachern, M. G. 2007 European food scares and their impact on EU food policy. Br. Food J. 109, 43-67. (doi:10.1108/ 00070700710718507)
51. Sinaceur, M., Heath, C. & Cole, S. 2005 Emotional and deliberative reactions to a public crisis mad cow disease in France. Psychol. Sci. 16, 247-254. (doi:10. 1111/j.0956-7976.2005.00811.x)
52. Rubin, G., Amlot, R., Rogers, M., Hall, I., Leach, S., Simpson, J. & Wessely, S. 2010 Perceptions and reactions with regard to pneumonic plague. Emerg. Infect Dis. 16, 120-122. (doi:10.3201/eid1601.081604)
53. Schmidt, C. 2008 The Yuck factor: where disgust meets discovery. Environ. Health Perspect. 116, A524-A527. (doi:10.1289/ehp.116-a524)
54. British Heart Foundation 2003 See http://www.you-tube.com/watch?v1/4cDAN7Oi62e0
55. Hammond, D., Fong, G. T., McDonald, P. W., Brown, S. & Cameron, R. 2004 Graphic Canadian cigarette warning labels and adverse outcomes: evidence from Canadian smokers. Am. J. Public Health 94, 1442-1445. (doi:10.2105/AJPH.94.8.1442)
56. Rozin, P. & Singh, L. 1999 The moralization of cigarette smoking in America. J. Consum. Behav. 8, 321-337.
57. Gilbert, G. 2005 Jamie's school dinners. UK (channel 4; p. 48 minutes).
58. Olatunji, B. O. & Broman-Fulks, J. J. 2007 A taxometric study of the latent structure of disgust sensitivity: converging evidence for dimensionality. Psychol. Assess. 19, 437-448. (doi:10.1037/1040-3590.19.4.437)
59. Olatunji, B. O., Lohr, J. M., Sawchuk, C. N. & Tolin, D. F. 2007 Multimodal assessment of disgust in contamination-related obsessive-compulsive disorder. Behav. Res. Ther. 45, 263-276. (doi:10.1016/j.brat. 2006.03.004)
60. Rasmussen, S. & Eisen, J. 1988 Clinical and epidemiologic findings of significance to neuropharmacologic trials in OCD. Psychopharmacol. Bull. 24, 466-470.
61. Rachman, S. 2004 Fear of contamination. Behav. Res. Ther. 42, 1227-1255. (doi:10.1016/j.brat.2003.10.009)
62. Tolin, D. F., Worhunsky, P. & Maltby, N. 2004 Sympathetic magic in contamination-related OCD. J. Behav. Ther. Exp. Psychiatry 35, 193-205. (doi:10. 1016/j.jbtep.2004.04.009)
63. Rubin, G. J., Amlôt, R., Page, L. & Wessely, S. 2009 Public perceptions, anxiety and behavioural change in relation to the swine flu outbreak: a cross-sectional telephone survey. Br. Med. J. 339, b2651. (doi:10.1136/ bmj.b2651)
64. Page, L., Seetharaman, S., Suhail, I., Wessely, S., Pereira, P. & Rubin, G. 2011 Using electronic patient records to assess the impact of swine flu (influenza H1N1) on mental health patients. J. Ment. Health 20, 60-69. (doi:10.3109/09638237.2010.542787)
65. Magee, W., Eaton, W., Wittchen, H., McGonagle, K. & Kessler, R. 1996 Agoraphobia simple phobia social phobia in the National Comorbidity Survey. Arch. Gen. Psychiatry 53, 159-168.
66. Muris, P., Merckelbach, H., Nederkoorn, S., Rassin, E., Candel, I. & Horselenberg, R. 2000 Disgust and psychopathological symptoms in a nonclinical sample. Pers. Indiv. Diff. 29, 1163-1167. (doi:10.1016/S01918869(99)00263-9)
67. Olatunji, B. O. & Sawchuk, C. N. 2005 Disgust: characteristic features, social manifestations and clinical implications. J. Soc. Clin. Psychol. 24, 932-962. (doi:10.1521/jscp.2005.24.7.932)
68. Davey, G. et al. 1998 A cross-cultural study of animal fears. Behav. Res. Ther. 36, 735-750. (doi:10.1016/S0005-7967(98)00059-X)
69. Woody, S. R., McLean, C. & Klassen, T. 2005 Disgust as a motivator of avoidance of spiders. J. Anxiety Disord. 19, 461-475. (doi:10.1016/j.janxdis.2004.04.002)
70. Fleischman, D. & Fessler, D. 2011 Progesterone's effects on the psychology of disease avoidance: support for the compensatory behavioral prophylaxis hypothesis. Horm. Behav. 59, 271-275. (doi:10.1016/j. yhbeh.2010.11.014)
71. Davey, G. C. L., Buckland, G., Tantow, B. & Dallos, R. 1998 Disgust and eating disorders. Eur. Eat. Disord. Rev. 6, 201-211. (doi:10.1002/(SICI)1099-0968(199809) 6:3,201::AID-ERV224.3.0.CO;2-E)
72. Troop, N. A., Treasure, J. L. & Serpell, L. 2002 A further exploration of disgust in eating disorders. Eur. Eat. Disord. Rev. 10, 218-226. (doi:10.1002/erv.444)
73. Mayer, B., Bos, A. E. R., Muris, P., Huijding, J. & Vlielander, M. 2008 Does disgust enhance eating disorder symptoms. Eat. Behav. 9, 124-127. (doi:10. 1016/j.eatbeh.2007.07.003)
74. Stein, R. I. & Nemeroff, C. J. 1995 Moral overtones of food: judgments of others based on what they eat. Pers. Soc. Psychol. Bull. 21, 480-490. (doi:10.1177/ 0146167295215006)
75. Park, J., Schaller, M. & Crandall, C. 2007 Pathogenavoidance mechanisms and the stigmatization of obese people. Evol. Hum. Behav. 28, 410-414. (doi:10. 1016/j.evolhumbehav.2007.05.008)
76. Rozin, P., Markwith, M. & Stoess, C. 1997 Moralization and becoming a vegetarian: the transformation of preferences into values and the recruitment of disgust. Psychol. Sci. 8, 67-73. (doi:10.1111/j.1467-9280. 1997.tb00685.x)
77. de Jong, P. J., van Lankveld, J., Elgersma, H. J. & Borg, C. 2010 Disgust and sexual problems-theoretical conceptualization and case illustrations. Int. J. Cogn. Ther. 3, 23-39. (doi:10.1521/ijct.2010.3.1.23)
78. Borg, C., De Jong, P. J. & Schultz, W. W. 2010 Vaginismus and dyspareunia: automatic vs. deliberate disgust responsivity. J. Sex. Med. 7, 2149-2157. (doi:10. 1111/j.1743-6109.2010.01800.x)
79. Fry, S. & Blumenbach, U. 2004 Paperweight, p. 84 London, UK: Arrow Books.
80. Monteiro, W. O., Noshirvani, H. F., Marks, I. M. & Lelliott, P. 1987 Anorgasmia from clomipramine in obsessive compulsive disorder: a controlled trial. Br. J. Psychiatry 151, 107-112. (doi:10.1192/bjp.151.1.107)
81. Olatunji, B. O., Elwood, L., Williams, N. & Lohr, J. 2008 Mental pollution and PTSD symptoms in victims of sexual assault: a preliminary examination of the mediating role of trauma-related cognitions. J. Cogn. Psychother. 22, 3747. (doi:10.1891/0889.8391.22.1.37)
82. Dalgleish, T. & Power, M. 2004 Emotion-specific and emotion-non-specific components of posttraumatic stress disorder (PTSD): implications for a taxonomy of related psychopathology. Behav. Res. Ther. 42, 1069-1088. (doi:10.1016/j.brat.2004.05.001)
83. De Jong, P. & Peters, M. 2009 Sex and the sexual dysfunctions: the role of disgust and contamination sensitivity. In Disgust and its disorders: theory, assessment, and treatment (eds B. Olatunji & D. McKay), pp. 253-270. Washington, DC: American Psychological Association.
84. Rubio-Godoy, M., Aunger, R. & Curtis, V. 2007 Serotonin-a link between disgust and immunity? Med. Hypotheses 68, 61-66. (doi:10.1016/j.mehy.2006.06.036)
85. De Barra, M., Aunger, R., Flieshmann, D. & Curtis, V. Submitted. Disgust and disease: sensitivity patterns and infection cues. J. Res. Personality.
86. Haidt, J., McCauley, C. & Rozin, P. 1994 Individual-differences in sensitivity to disgust-a scale sampling 7 domains of disgust elicitors. Pers. Indiv. Diff. 16, 701-713. (doi:10. 1016/0191-8869(94)90212-7)
87. Olatunji, B. O., Williams, N. L., Tolin, D. F., Abramowitz, J. S., Sawchuk, C. N., Lohr, J. M. & Elwood Lisa, S. 2007 The disgust scale: item analysis, factor structure, and suggestions for refinement. Psychol. Assess. 19, 281-297. (doi:10.1037/1040-3590.19.3.281)
88. Rozin, P., Haidt, J., McCauley, C., Dunlop, L. & Ashmore, M. 1999 Individual differences in disgust sensitivity: comparisons and evaluations of paper-andpencil versus behavioral measures. J. Res. Pers. 33, 330-351. (doi:10.1006/jrpe.1999.2251)
89. Curtis, V. 2011 Disgust. In The encyclopaedia of human behaviour (ed. V. Ramachandranagain), 2nd edn. Oxford, UK: Elsevier.
90. Karvonen, A., Seppala, O. & Valtonen, E. T. 2004 Parasite resistance and avoidance behaviour in preventing eye fluke infections in fish. Parasitology 129, 159-164. (doi:10.1017/S0031182004005505)
91. Krause, J. & Godin, J.-G. J. 1994 Influence of parasitism on the shoaling behaviour of banded killifish, Fundulus diaphanus. Can. J. Zool. 72, 1775-1779. (doi:10.1139/z94-240)
92. Keisecker, J., Skelly, D., Beard, K. & Preisser, E. 1999 Behavioral reduction of infection risk. Proc. Natl Acad. Sci. USA 96, 9165-9168. (doi:10.1073/pnas.96.16.9165)
93. Kavaliers, M. & Colwell, D. D. 1995 Discrimination by female mice between the odours of parasitized and nonparasitized males. Proc. R. Soc. Lond. B 261, 31-35. (doi:10.1098/rspb.1995.0113)
94. Behringer, D. C., Butler, M. J. & Shields, J. D. 2006 Avoidance of disease by social lobsters. Nature 441, 421. (doi:10.1038/441421a)
95. Goodall, J. 1986 Social rejection, exclusion, and shunning among the Gombe chimpanzees. Ethol. Sociobiol. 7, 227-236. (doi:10.1016/0162-3095(86) 90050-6)
96. Park, J. H., Faulkner, J. & Schaller, M. 2003 Evolved disease-avoidance processes and contemporary antisocial behavior: prejudicial attitudes and avoidance of people with physical disabilities. J. Nonverbal Behav. 27, 65-87. (doi:10.1023/A:1023910408854)
97. Park, J. H., Schaller, M. & Crandall, C. S. 2007 Pathogen-avoidance mechanisms and the stigmatization of obese people. Evol. Hum. Behav. 28, 410-414. (doi:10.1016/j.evolhumbehav.2007.05.008)
98. Kurzban, R. & Leary, M. R. 2001 Evolutionary origins of stigmatization: the functions of social exclusion. Psychol. Bull. 127, 187-208. (doi:10.1037/0033-2909. 127.2.187)
99. Park, J. H., Faulkner, J. & Schaller, M. 2003 Evolved disease-avoidance processes and contemporary anti-social behavior: prejudicial attitudes and avoidance of people with physical disabilities. J. Nonverbal Behav. Brain Sci. 27, 65-87. (doi:10.1023/A:1023910408854)
100. Duncan, L. A. & Schaller, M. 2009 Prejudicial attitudes toward older adults may be exaggerated when people feel vulnerable to infectious disease: evidence and implications. Anal. Soc. Issues Public Policy 9, 97-115. (doi:10.1111/j.1530-2415.2009.01188.x)
101. Fincher, C. & Thornhill, R. In press. Parasite-stress promotes in-group assortative sociality: the cases of strong family ties and heightened religiosity. Brain Behav. Sci.
102. Taylor, K. E. 2009 Cruelty: human evil and the human brain. Oxford, UK: Oxford University Press.
103. Charteris-Black, J. 2006 Britain as a container: immigration metaphors in the 2005 election campaign. Discourse Society 17, 563-581. (doi:10.1177/ 0957926506066345)
104. Wilkinson, S. I. 2006 Votes and violence: electoral competition and ethnic riots in India. Cambridge, UK: Cambridge University Press.
105. Magin, P., Adams, J., Heading, G., Pond, D. & Smith, W. 2006 Psychological sequelae of acne vulgaris: results of a qualitative study. Can. Family Phys. 52, 978.
106. Alio, A. P., Merrell, L., Roxburgh, K., Clayton, H. B., Marty, P. J., Bomboka, L., Traorè, S. & Salihu, H. M. 2010 The psychosocial impact of vesico-vaginal fistula in Niger. Arch. Gynecol. Obstet. 284, 1-8.
107. Dahle, R. 1999 Lukt, fukt og skam [Bodily smells, wetness and shame]. Paper presented at Norsk Selskap for aldersforskning, Oslo, 9 September 1999.
108. Isaksen, L. W. 2002 Toward a sociology of (gendered) disgust images of bodily decay and the social organization of care work. J. Family Issues 23, 791-811. (doi:10.1177/019251302236595)
109. Wrubel, J. & Folkman, S. 1997 What informal caregivers actually do: the caregiving skills of partners of men with AIDS. AIDS Care 9, 691-706. (doi:10. 1080/713613223)
110. Hochschild, A. R. 1983 The managed heart: the commercialization of human feelings. Berkeley, CA: University of California Press.
111. Mendelsohn, O. & Vicziany, M. 1998 The untouchables: subordination, poverty, and the state in modern India. Cambridge, UK: Cambridge University Press.
112. Livingstone-Smith, D. 2011 Less than human: why we demean, enslave and exterminate others. New York, NY: St Martin's Press.
113. Brandt, A. M. 1988 AIDS in historical perspective: four lessons from the history of sexually transmitted diseases. Am. J. Public Health 78, 367. (doi:10.2105/ AJPH.78.4.367)
114. Pastore, J. L. 1993 Confronting AIDS through literature: the responsibilities of representation. Champaign, IL: University of Illinois Press.
115. Brown, L., Macintyre, K. & Trujillo, L. 2003 Interventions to reduce HIV/AIDS stigma: what have we learned? AIDS Educ. Prev. 15, 49-69. (doi:10.1521/ aeap.15.1.49.23844)
116. Schaich Borg, J., Lieberman, D. & Kiehl, K. A. 2008 Infection, incest, and iniquity: investigating the neural correlates of disgust and morality. J. Cogn. Neurosci. 20, 1529-1546. (doi:10.1162/jocn.2008.20109)
117. Zhong, C. B. & Liljenquist, K. 2006 Washing away your sins: threatened morality and physical cleansing. Science 313, 1451-1452. (doi:10.1126/science.1130726)
118. Schnall, S., Benton, J. & Harvey, S. 2008 With a clean conscience. Psychol. Sci. 19, 1219-1222. (doi:10.1111/ j.1467-9280.2008.02227.x)
119. Zhong, C. B., Strejcek, B. & Sivanathan, N. 2010 A clean self can render harsh moral judgment. J. Exp. Soc. Psychol. 46, 859-862. (doi:10.1016/j.jesp.2010.04.003)
120. Fayard, J. V., Bassi, A. K., Bernstein, D. M. & Roberts, B. W. 2009 Is cleanliness next to godliness? Dispelling old wives' tales: failure to replicate Zhong and Liljen quist (2006). J. Articles Support Null Hypothesis 6, 22.
121. Danovitch, J. & Bloom, P. 2009 Children's extension of disgust to physical and moral events. Emotion 9, 107-112. (doi:10.1037/a0014113)
122. Nussbaum. 2004 Hiding from humanity: disgust, shame and the law. Princeton, NJ: Princeton University Press.
123. Kass, L. 1997 The wisdom of repugnance. New Republic 216, 17-26.
124. Aunger, R. & Curtis, V. 2008 Kinds of behaviour. Biol. Phil. 23, 317-345. (doi:10.1007/s10539-007-9108-4)
125. Barrett, L. F. 2006 Are emotions natural kinds? Perspect. Psychol. Sci. 1, 28-58. (doi:10.1111/j.1745-6916.2006. 00003.x)
126. Griffiths, P. E. 1997 What emotions really are: the problem of psychological categories. Chicago, IL: University of Chicago Press.
127. Henrich, J. 2004 Cultural group selection, coevolutionary processes and large-scale cooperation. J. Econ. Behav. Organ. 53, 3-35. (doi:10.1016/S0167-2681(03)00094-5)
128. Fehr, E. & Fischbacher, U. 2003 The nature of human altruism. Nature 425, 785-791. (doi:10.1038/ nature02043)
129. West, S. A., Griffin, A. S. & Gardner, A. 2007 Evolutionary explanations for cooperation. Curr. Biol. 17, R661-R672. (doi:10.1016/j.cub.2007.06.004)
130. Unicef, WHO. 2009 Diarrhoea: why children are still dying and what can be done. New York, NY: Unicef.