Presentation on disgust and social judgment at Ithaca Science Cabaret on March 23, 2010.

1. Grossiology:
How disgust shapes our social judgment
david pizarro
cornell university/department of psychology

2. in collaboration with Yoel Inbar
http://www.yoelinbar.net/

3. Disgust

4. Disgust
“A sense of aversion to something perceived as
dangerous because of its powers to contaminate,
infect, or pollute by proximity, contact, or ingestion.”
(Miller, 1998).

6. • human universal

7. • human universal
• “basic” emotion:
characteristic facial
expression

8. • human universal
• “basic” emotion:
characteristic facial
expression
• animals and animal by-
products

9. • human universal
• “basic” emotion:
characteristic facial
expression
• animals and animal by-
products
• Feces

10. • human universal
• “basic” emotion:
characteristic facial
expression
• animals and animal by-
products
• Feces
• Urine

11. • human universal
• “basic” emotion:
characteristic facial
expression
• animals and animal by-
products
• Feces
• Urine
• Blood

12. • human universal
• “basic” emotion:
characteristic facial
expression
• animals and animal by-
products
• Feces
• Urine
• Blood
• Vomit

13. • human universal
• “basic” emotion:
characteristic facial
expression
• animals and animal by-
products
• Feces
• Urine
• Blood
• Vomit
• Rotten flesh

14. • human universal
• “basic” emotion:
characteristic facial
expression
• animals and animal by-
products
• Feces
• Urine
• Blood
• Vomit
• Rotten flesh
• Most meat

15. • human universal
• “basic” emotion:
characteristic facial
expression
• animals and animal by-
products
• Feces
• Urine
• Blood
• Vomit
• Rotten flesh
• Most meat
• emerges (rather) late in
development

16. • human universal
• “basic” emotion:
characteristic facial
expression
• animals and animal by-
products
• Feces
• Urine
• Blood
• Vomit
• Rotten flesh
• Most meat
• emerges (rather) late in
development
• protection against
contamination

17. dedicated neural structures?
• brain imaging studies show anterior insula
activation
• patients with Huntington’s Disease show
disgust deficits (recognition of disgust faces,
response to foul tastes and smells, self-report)

20. *easily elicited

27. the effects of disgust
• provides strong behavioral motivation to expel,
avoid, push-away, get rid of, etc.
• but emotions don’t just influence behavior...

28. ...emotions influence
judgment
“The emotions are all those feelings that so change men as
to affect their judgments, …such are anger, pity, fear and the
like, with their opposites…. Take, for instance, the emotion of
anger: here we must discover…what the state of mind of
angry people is, who the people are with whom they usually
get angry, and on what grounds they get angry with them. It is
not enough to know one or even two of these points; …the
same is true of the other emotions” (Aristotle, Rhetoric, Book
2, Chapter 1).

29. disgust and moral judgment

30. disgust and moral judgment
• disgust may be especially implicated in
ethical systems which emphasize purity and
divinity (Haidt & Graham, 2006)

31. disgust and moral judgment
• disgust may be especially implicated in
ethical systems which emphasize purity and
divinity (Haidt & Graham, 2006)
• in these ethical systems, a cue to “badness”
is “dirtiness”.

32. disgust and moral judgment
• disgust may be especially implicated in
ethical systems which emphasize purity and
divinity (Haidt & Graham, 2006)
• in these ethical systems, a cue to “badness”
is “dirtiness”.
–conversely, clean = morally good

33. disgust and moral judgment
• disgust may be especially implicated in
ethical systems which emphasize purity and
divinity (Haidt & Graham, 2006)
• in these ethical systems, a cue to “badness”
is “dirtiness”.
–conversely, clean = morally good
• inducing disgust for an individual can lead to
a diminished moral respect and/or harsher
treatment (Haidt & Wheatley, 2005; Schnall, Haidt & Clore, 2006)

34. varieties of disgust
• Core Disgust--I’m disgusted by rotten meat.
• Moral Disgust--”I’m disgusted by G.W.”
• Metaphorical?
• Real disgust?
• Recent neurological evidence (Moll et al., 2005),
and facial EMG data (Chapman et al., 2009)

35. distaste --> core disgust --> moral disgust
Chapman et al, Science, 2009

36. disgust readily extends to people

37. disgust readily extends to people

38. disgust readily extends to people
“In Tierra del Fuego a native
touched with his finger some
cold preserved meat while I
was eating at our bivoac; and
plainly showed disgust at its
softness; whilst I felt utter
disgust at my food being
touched by a naked savage,
though his hands did not
appear dirty”

39. disgust and dirty “others”

40. disgust and dirty “others”
“Thus, throughout history, certain disgust properties --
sliminess, bad smell, stickiness, decay, foulness -- have
repeatedly and monotonously been associated with…
Jews, women, homosexuals, untouchables, lower-class
people -- all of those are imagined as tainted by the dirt
of the body”
- Martha Nussbaum

43. “Just look at these guys! The
louse-infested beards! The filthy,
protruding ears, Those stained,
fatty clothes…
Jews often have an unpleasant
sweetish odor. If you have a good
nose, you can smell the Jews."
(Nazi Children’s Book, 1938)

45. gays are…
• “worthy of death for their vile...sex practices…
• “filthy”
• like “dogs eating their own vomit and sows
wallowing in their own feces”
-www.godhatesfags.com

46. gross [moral] offense?
“We’re living in a time that a lifestyle that at one time was on
the list of mental disorders, called sodomy, is now called an
alternative lifestyle. The Bible calls it abomination. Abomination
is something disgusting.”
Pastor Tim Oldfield, quoted in Kingdom Coming (pp. 74)

47. evidence: inducing core disgust
makes individuals harsh moral
judges
• study: dirty desks
– Brought people into the lab to fill out questionnaires
asking for moral judgments
• e.g., Joe stole 50 dollars from his friend
– Completed them on a dirty, disgusting desk vs. on a
clean desk
• study: hypnotic disgust
– Participants were hypnotized and told to feel flashes
of disgust when they read a trivial word
– Disgust made people more harsh in their judgments
of others
• In both cases, people were harsher in their judgments of
others.

48. are people who are easily
disgusted more likely to adopt
some of these moral beliefs?

49. disgust sensitivity
questionnaire
(Haidt, McCauley, & Rozin, 1994)

50. disgust sensitivity
questionnaire
(Haidt, McCauley, & Rozin, 1994)
• sample items (“core disgust”) :

51. disgust sensitivity
questionnaire
(Haidt, McCauley, & Rozin, 1994)
• sample items (“core disgust”) :
- I try to avoid letting any part of my body touch the toilet
seat in a public restroom, even when it appears clean.

52. disgust sensitivity
questionnaire
(Haidt, McCauley, & Rozin, 1994)
• sample items (“core disgust”) :
- I try to avoid letting any part of my body touch the toilet
seat in a public restroom, even when it appears clean.
- Even if I were hungry, I would not drink a bowl of my
favorite soup if it had been stirred by a used but thoroughly
washed fly-swatter.

53. disgust sensitivity
questionnaire
(Haidt, McCauley, & Rozin, 1994)
• sample items (“core disgust”) :
- I try to avoid letting any part of my body touch the toilet
seat in a public restroom, even when it appears clean.
- Even if I were hungry, I would not drink a bowl of my
favorite soup if it had been stirred by a used but thoroughly
washed fly-swatter.
- While you are walking through a tunnel under a railroad
track, you smell urine.

54. disgust sensitivity
questionnaire
(Haidt, McCauley, & Rozin, 1994)
• sample items (“core disgust”) :
- I try to avoid letting any part of my body touch the toilet
seat in a public restroom, even when it appears clean.
- Even if I were hungry, I would not drink a bowl of my
favorite soup if it had been stirred by a used but thoroughly
washed fly-swatter.
- While you are walking through a tunnel under a railroad
track, you smell urine.
• not the same as other personality measures

55. disgust sensitivity
questionnaire
(Haidt, McCauley, & Rozin, 1994)
• sample items (“core disgust”) :
- I try to avoid letting any part of my body touch the toilet
seat in a public restroom, even when it appears clean.
- Even if I were hungry, I would not drink a bowl of my
favorite soup if it had been stirred by a used but thoroughly
washed fly-swatter.
- While you are walking through a tunnel under a railroad
track, you smell urine.
• not the same as other personality measures
• predicts behavior

56. disgusting politics

57. disgust & political
conservatism
Inbar, Pizarro & Bloom (2009) Cognition and Emotion, 23, 714-725.

58. disgust & political
conservatism
Inbar, Pizarro & Bloom (2009) Cognition and Emotion, 23, 714-725.
• N=181 participants from Iowa, Wisconsin,
Ohio, Illinois (“swing” states)

59. disgust & political
conservatism
Inbar, Pizarro & Bloom (2009) Cognition and Emotion, 23, 714-725.
• N=181 participants from Iowa, Wisconsin,
Ohio, Illinois (“swing” states)
– Disgust Sensitivity correlated with political
conservatism, r(181) = .21, p < .01.

60. disgust & political
conservatism
Inbar, Pizarro & Bloom (2009) Cognition and Emotion, 23, 714-725.
• N=181 participants from Iowa, Wisconsin,
Ohio, Illinois (“swing” states)
– Disgust Sensitivity correlated with political
conservatism, r(181) = .21, p < .01.
• N=82 UCI undergrads

61. disgust & political
conservatism
Inbar, Pizarro & Bloom (2009) Cognition and Emotion, 23, 714-725.
• N=181 participants from Iowa, Wisconsin,
Ohio, Illinois (“swing” states)
– Disgust Sensitivity correlated with political
conservatism, r(181) = .21, p < .01.
• N=82 UCI undergrads
– Disgust Sensitivity correlated with Political
Conservatism; r(82)=.29, p < .01

62. follow-up study (cornell
university)

63. follow-up study (cornell
university)
• Full (32-item) DS Scale, better measure of political
orientation, asked about specific political beliefs

64. follow-up study (cornell
university)
• Full (32-item) DS Scale, better measure of political
orientation, asked about specific political beliefs
• DS and Political Conservatism, r(81) = .26, p < .05.

65. follow-up study (cornell
university)
• Full (32-item) DS Scale, better measure of political
orientation, asked about specific political beliefs
• DS and Political Conservatism, r(81) = .26, p < .05.
• Explained by sociomoral beliefs

66. follow-up study (cornell
university)
• Full (32-item) DS Scale, better measure of political
orientation, asked about specific political beliefs
• DS and Political Conservatism, r(81) = .26, p < .05.
• Explained by sociomoral beliefs
– Gay Marriage

67. follow-up study (cornell
university)
• Full (32-item) DS Scale, better measure of political
orientation, asked about specific political beliefs
• DS and Political Conservatism, r(81) = .26, p < .05.
• Explained by sociomoral beliefs
– Gay Marriage
– Abortion

68. more disgust sensitive = greater
opposition to gay marriage

69. more disgust sensitive = greater
opposition to gay marriage

70. more disgust sensitive = greater
opposition to abortion

71. more disgust sensitive = greater
opposition to abortion

72. disgust sensitivity not associated
with:
• Death Penalty
• Affirmative Action
• Welfare
• Gun-Control

73. disgust sensitivity predicts
implicit anti-gay attitudes
Inbar, Pizarro, Knobe & Bloom (2009) Emotion, 9, 435-439.
Straight Gay

74. disgust sensitivity predicts
implicit anti-gay attitudes
Inbar, Pizarro, Knobe & Bloom (2009) Emotion, 9, 435-439.
Straight Gay
• N = 48 Cornell Undergraduates

75. disgust sensitivity predicts
implicit anti-gay attitudes
Inbar, Pizarro, Knobe & Bloom (2009) Emotion, 9, 435-439.
Straight Gay
• N = 48 Cornell Undergraduates
• Given Disgust-Sensitivity Scale, Political Items, and Gay/Straight
IAT

76. disgust sensitivity predicts
implicit anti-gay attitudes
Inbar, Pizarro, Knobe & Bloom (2009) Emotion, 9, 435-439.
Straight Gay
• N = 48 Cornell Undergraduates
• Given Disgust-Sensitivity Scale, Political Items, and Gay/Straight
IAT
• Disgust Sensitivity predicts implicit anti-gay attitudes

77. disgust sensitivity predicts
implicit anti-gay attitudes
Inbar, Pizarro, Knobe & Bloom (2009) Emotion, 9, 435-439.
Straight Gay
• N = 48 Cornell Undergraduates
• Given Disgust-Sensitivity Scale, Political Items, and Gay/Straight
IAT
• Disgust Sensitivity predicts implicit anti-gay attitudes
• Follow-up: disgust sensitivity correlated with the extent to which
people perceive encouraging homosexuality as intentional

78. could manipulating disgust affect
anti-gay bias?

79. could manipulating disgust affect
anti-gay bias?
• two studies conducted on cornell
university undergraduates

80. could manipulating disgust affect
anti-gay bias?
• two studies conducted on cornell
university undergraduates
• first completed a political attitudes
questionnaire

81. could manipulating disgust affect
anti-gay bias?
• two studies conducted on cornell
university undergraduates
• first completed a political attitudes
questionnaire
• next completed a gay/lesbian feeling
thermometer

82. could manipulating disgust affect
anti-gay bias?
• two studies conducted on cornell
university undergraduates
• first completed a political attitudes
questionnaire
• next completed a gay/lesbian feeling
thermometer
• manipulation

83. could manipulating disgust affect
anti-gay bias?
• two studies conducted on cornell
university undergraduates
• first completed a political attitudes
questionnaire
• next completed a gay/lesbian feeling
thermometer
• manipulation
–for half of the participants, a foul odor was
sprayed in the garbage can of the lab

85. bad smell = greater anti-gay
feelings
,-./0*1$
2314536$
738039.$
)*+$
!"#$ !%&$ !%#$ !'&$ !'#$ !(&$ !(#$ !&$ #$
*straight-gay diff., standardized

86. “gut” morality
• The need to protect the body against
contaminants likely gave rise to disgust
reaction
• Strong, visceral motivation to avoid and expel
foul stimuli
• Applied to people, it can lead to harsh
judgments and moral rejection when
individuals and groups are perceived as
disgusting.

87. from dirt to cleanliness: the
motivation to stay clean
• disgust mechanism = focus on contamination?
• could physical cleanliness also give rise to a
similar concern with contamination?
– once your car is washed, vigilant of puddles and
parking under trees
– teeth-cleaning makes me avoid coffee for a day or two

89. hand-washing and moral purity
• all participants brought into a lab and asked to
complete demographics, political orientation
(moral, fiscal, social)
• moral judgment items
–moral purity (non-sexual)
–moral purity (sexual)
–moral (non-purity)
• in hand washing condition, big sign to remind
participants to wash hands
• asked to wash hands before moral judgment
items (or not)

90. moral judgment items
(examples)
• Moral (non-purity)
– In order to increase her chances of getting a job at a prestigious
firm, a college graduate writes an reference letter that honestly
details her strengths, but signs it with the name of a former boss
(whom she knew liked her).
• Moral (sexual purity)
– After they have been sexually active for over a year, a woman and
her boyfriend discover that they have the same father-- they are
actually half brother and sister, but were raised in separate families
from the time they were born. They decide that the new information
doesn't matter, and continue their sexual relationship. The couple is
careful to use protection.

91. moral judgment
y axis represents moral approval
No main effect of condition or item type
Condition X Item interaction, F (2, 58) = 3.90, p < .05
Condition simple effect significant for sexual purity items only, t (60) = 3.04, p < .01

92. unexpected: clean hands affected
political orientation
(higher numbers = more liberal)
y axis represents self-reported liberalism (social, moral, fiscal)
t (60) = 3.09, p < .01

93. political orientation?:
field study
• could a hand-washing reminder alone influence
political orientation in a public setting?
• participants randomly asked to complete one-
page demographic questionnaire including 3
political orientation items
• either asked to do it “by the hand cleaning” stand
(placed on the left or right of the entrance to
building)
43

94. 44

95. political orientation: field study
(lower numbers = more conservative)
y axis represents self-reported liberalism (social, moral, fiscal)
t (52) = 2.31, p < .05

96. should disgust/cleanliness play a
role in moral judgment?
(Inbar & Pizarro, 2009)
• Leon Kass famously argued that disgust was a reliable cue
that something was wrong.
– Without disgust we are “souls who have forgotten to
shudder”.
• nonetheless, the degree to which disgust can unduly
influence judgments of individuals and groups should lead
us to be wary of its effects.
• an emotion that arose in order to keep us from eating
poisons should perhaps not be used to determine the
moral worth of others

97. thank you!
For published papers mentioned here:
www.peezer.net