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RESEARCH ARTICLE
Experimentally Inducing Disgust Reduces Desire for Short-Term Mating
Laith Al-Shawaf
1
&David M. G. Lewis
2
&Maliki Eyvonne Ghossainy
3
&David M. Buss
4
#Springer Nature Switzerland AG 2018
Abstract
Short-term mating strategies involve casual sex, multiple partners, and short-time intervals before initiating intercourse. Such
strategies should be difficult to implement in the presence of high levels of sexual disgust. Researchers have therefore
suggested—and found evidence for—the hypothesis that individuals with a stronger proclivity for short-term mating have lower
levels of sexual disgust. Here, we suggest a related hypothesis: inducing sexual disgust should reduce desire for short-term
mating. Experiment 1 (N= 341) and experiment 2 (N= 361) investigated the effects of disgust induction on desire for short-term
mating. Both studies found that inducing disgust reduces desire for short-term mating, and that the effect of sexual disgust is
particularly strong. These results support the novel hypothesis advanced here and corroborate the broader hypothesis that reduced
sexual disgust is a previously undiscovered design feature of short-term mating strategies.
Keywords Disgust .Emotions .Evolutionary psychology .Sexual disgust .Mating .Short-term mating
Introduction
The emotion of disgust and the psychology of human mating
have conceptual relevance for one another, but have largely
been studied in isolation. Recent research has begun to bridge
these two areas of inquiry (Al-Shawaf et al. 2015a,b,c; Borg
and de Jong 2012; Curtis, de Barra, & Aunger, 2011;
DeBruine et al. 2010; Jones et al. 2013;deJongetal,2009;
de Jong et al., 2010;deJongetal.,2013; Lee et al. 2014; Little
et al. 2011; Tybur and Gangestad 2011; Tybur et al. 2011).
Such work has found, for example, a bidirectional relationship
between disgust and sexual arousal. Sexual arousal can inhibit
disgust (e.g., Ariely and Loewenstein 2006), but disgust can
also inhibit sexual arousal (e.g., Fleischman et al. 2015). The
bidirectional nature of the relationship between disgust and
mating is important: mating is a crucial aspect of human life,
but disgust must be inhibited in order to facilitate successful
sexual congress. On the other hand, disgust mustbe capable of
inhibiting or shutting down sexual arousal in extreme circum-
stances, such as when cues to pathogens are powerful and
numerous, or when new information is discovered that renders
a potential mate unsuitable (e.g., he is abusive, she has a sex-
ually transmitted infection, he is a close-genetic relative).
Despite recent advances in disgust research and mating
research, much work remains in connecting these conceptual-
ly related domains. Recent research bridging the two has
found that individuals with a stronger proclivity for short-
term mating have lower levels of sexual disgust than their less
short-term-oriented counterparts (Al-Shawaf et al. 2015c).
Researchers predicted this finding based on a task analysis
of short-term mating strategies: because short-term mating
involves casual sex, multiple sex partners, and intercourse
after brief periods of acquaintance, implementing this strategy
would be difficult without a functional reduction in sexual
disgust levels. Two independent studies supported this hy-
pothesis (Al-Shawaf et al. 2015c), and these findings have
now been replicated by an independent group of researchers
using a large online sample (O’Shea et al. in press).
If low levels of sexual disgust are a key facilitator of short-
term mating strategies, then experimentally inducing sexual
disgust should reduce people’s desire for short-term mating.
This paper reports two experiments designed to test this
hypothesis.
*Laith Al-Shawaf
lalshawa@uccs.edu
1
Department of Psychology, University of Colorado, Colorado
Springs, USA
2
School of Psychology and Exercise Science, Murdoch University,
Perth, Australia
3
Department of Psychology, American University of Beirut,
Beirut, Lebanon
4
Department of Psychology, The University of Texas at Austin,
Austin, TX, USA
Evolutionary Psychological Science
https://doi.org/10.1007/s40806-018-0179-z
Different Forms of Disgust—and Their Relevance
to Short-Term Mating
Recent research has identified three types of disgust: pathogen
disgust,sexual disgust,andmoral disgust (Tybur et al. 2009,
2012). These three types of disgust are distinguished by the
social and ecological inputs that activate them, the distinct
behavioral outputs that they motivate, and their unique pro-
files of correlations with other psychological variables.
Our reasoning specifically implicates sexual disgust as rel-
evant to short-term mating. Consistent with this, individuals
dispositionally inclined toward short-term mating exhibit low
levels of sexual disgust, but not pathogen or moral disgust (Al-
Shawaf et al. 2015c). Conceptually, however, pathogen dis-
gust is also relevant to short-term mating: an important cost of
short-term mating is increased risk of transmission of sexually
transmitted infections and other contagious diseases (National
Center for HIV/AIDS, viral hepatitis, STD, and TB
Prevention 2011). Some cues—such as a nude human body
covered in sores or lesions—should trigger both pathogen
disgust and sexual disgust.
Al-Shawaf and colleagues reasoned that the absence of a
relationship between pathogen disgust and short-term mating
might be an artifact of the nature of pathogen disgust mea-
sures. The pathogen disgust subscale of the Three-Domain
Disgust Scale—arguably the most conceptually sound and
psychometrically valid disgust measure (Al-Shawaf and
Lewis 2013; Haidt et al. 1994; Tybur et al. 2009 for more
detail)—appears to be constructed so as to index Bpure^path-
ogen disgust: pathogen disgust that does not overlap with
measures of other forms of disgust. Developing an instrument
with conceptually distinct subscales for pathogen and sexual
disgust entails excluding items that simultaneously tap both
types of disgust. Although sexual and pathogen disgust have
some non-overlapping domains (e.g., rotting meat might in-
duce pathogen disgust but not sexual disgust, incest might
induce sexual disgust but not pathogen disgust), sexual con-
tact is a key pathogen-transmission vector. This importance of
sexual contact as a pathogen vector renders the two domains
inherently linked—a linkage not fully captured by the design
of the extant three-factor measure of disgust.
We predicted that a more naturalistic investigation of path-
ogen disgust—or an investigation that does not limit itself to
Bpure^pathogen cues—would find a relationship between
pathogen disgust and short-term mating. We expect images
of diseased human bodies, for example, to trigger pathogen
disgust and sexual disgust because of the infection risks inher-
ent in sexual contact.
In the current experiments, we do not limit ourselves to
Bpure^pathogen cues, and so we expect that inducing patho-
gen disgust will have an effect on short-term mating desire.
However, because only a limited subset of pathogen cues
should be relevant to short-term mating (e.g., diseased bodies,
but not rodents or rotting food), we predicted that the effect of
pathogen disgust on short-term mating desire would be weak-
er than the effect of sexual disgust.
Experiment 1: the Effect of Disgust Induction
on Short-Term Mating
Experiment 1 aimed to determine the impact of experimental-
ly induced disgust on desire for short-term mating. We includ-
ed four experimental conditions: sexual disgust, pathogen dis-
gust, a neutral control condition, and a threatening control. We
did not have any hypotheses about the threatening control
group; we included it to permit discrimination between the
effects of negative emotion induction in general and disgust
induction specifically.
Method
Participants
Three hundred fifty two participants (179 men, 162 women;
M
age
= 19.21, SD
age
= 1.44, age range: 18–28 years) were
recruited from the psychology subject pool at The
University of Texas at Austin to participate in a study about
Bdisgust and human mating^. Sample size was determined
before any data analysis. Participant breakdown by experi-
mental condition was as follows: sexual disgust: 86 (40
males), pathogen disgust: 87 (45 males), neutral control: 82
(45 males), and threatening control: 86 (49 males).
Participants arrived at the laboratory, provided informed con-
sent to participate in the study, and were escorted by a re-
searcher to a private room where they completed the experi-
ment. Participants received partial course credit for their par-
ticipation and were debriefed upon completion.
Design
Experiment 1 was a 2 × 4 mixed-design ANOVA with one
within-subjects factor (interest in short-term mating: pre- and
post-manipulation) and one between-subjects factor (experi-
mental condition: sexual disgust, pathogen disgust, neutral
control, and threatening control).
The experimental manipulation differed for each group: the
sexual disgust group looked at a set of 20 images that included
nude elderly individuals, genitalia exhibiting cues to sexually
transmitted disease, and similar sexual disgust stimuli; all ob-
tained from the web. Participants in this group were also
instructed to Bplease imagine what it would be like to be in a
sexually intimate situation with the person depicted in this
picture^. These instructions served to make the sexual aspect
of the situation more salient, thereby making it more likely
that participants’primary reaction would be sexual disgust
Evolutionary Psychological Science
rather than pathogen or moral disgust. The pathogen disgust
group viewed a series of 20 images designed to induce disgust
associated with pathogen vectors, including diseased human
bodies, rotting food items, rodents, and feces. The threatening
control group viewed a series of 20 images of men in menac-
ing poses, pointing guns directly at the screen (adapted from
Schaller et al. 2010). Participants viewed the slides for as long
as they chose to: they had to click Bnext^to proceed to the
next image. This was to prevent participants from simply
closing their eyes and allowing the slideshow to finish without
having viewed the stimuli. The neutral control group did not
undergo any experimental manipulation.
Participants in each group completed a measure of interest
in short-term mating both prior to and after exposure to the
respective experimental stimuli. Finally, participants
responded to items designed to assess current disgust levels,
as well as other instruments as part of a broader study. The
order of materials was as follows: pre-measure of short-term
mating desire, experimental disgust induction, measure of cur-
rent disgust, post-measure of short-term mating desire, Three-
Domain Disgust Scale, and finally demographic questions.
All stimuli are available upon request from the first author.
Materials
Current Interest in Short-Term Mating Because we were inter-
ested in current short-term mating desire—as opposed to dis-
positional orientation toward short-term mating—the standard
sociosexual orientation inventory (SOI-R, Penke and
Asendorpf 2008)wouldnothavebeenanappropriatemea-
sure. Accordingly, we designed a four-item scale to index
current interest in short-term mating. This scale consisted of
the following items, which were evaluated on a Likert-type
scale: BHow hard would it be for you to experience a sexual
fantasy right now?^(reverse coded), BRight now, how com-
fortable would you be having sex with somebody that you just
met?^,BIf you went on a first date with somebody tonight,
how willing do you think you would be to have sex with him
or her on the first date?^, and BHow desirable [as a mate]
would someone have to be in order for you to have sex with
that person on the first date?^(reverse coded). Participants
completed this scale before and after the experimental disgust
manipulation.
Current Disgust We included an author-generated measure of
current, state-level disgust to assess the effectiveness of our
manipulation. We reasoned that our brief disgust induction
would affect current disgust levels, but not the stable, dispo-
sitional disgust sensitivity measured by the Three-Domain
Disgust Scale. We therefore generated two items intended to
serve as a brief, face-valid method of capturing current dis-
gust. These two items were BHow disgusting did you find the
series of images you just saw?^and BHow disgusted do you
feel right now?^
Results
Manipulation Check
We tested the efficacy of our disgust induction procedure
by comparing the post-manipulation disgust levels across
condition, excluding participants in the neutral control
condition, who did not view any images. A one-way
ANOVA confirmed that there were significant differences
in disgust levels across conditions, F(2, 254) = 124.49,
p< .001, partial η
2
= .50. Disgust means and standard
deviations for each experimental condition were as fol-
lows: sexual 13.27 (SD = 1.76), pathogen 10.58 (SD =
2.93), and threatening control 6.47 (SD = 3.56), Post-
hoc tests revealed significant differences in disgust be-
tween all three groups. The sexual disgust group exhibit-
ed the highest levels of disgust—significantly higher than
the pathogen disgust group (difference between means =
2.69, SE = .37, p< .001) and the threatening control
group (difference between means = 6.80, SE = .43,
p< .001). Additionally, the pathogen disgust group ex-
hibited significantly higher disgust than the threatening
control group (difference between means = 4.11,
SE = .50, p< .001).
Descriptive Statistics
Tab le 1presents means and standard deviations for the three
disgust scales (Cronbach’sα: moral = .88, sexual = .88, path-
ogen = .82) and the scale measuring current desire for short-
term mating (pre-manipulation α= .71, post-manipulation
α=.73).
Sex differences in disgust followed a similar pattern to
those reported by Tybur et al. (2009,2011). Consistent with
previous research, women exhibited higher levels of sexual
disgust [t(333) = −12.87, p<.001,d= 1.40], pathogen disgust
[t(332) = −4.40, p< .001, d= 0.48], and moral disgust
[t(333) = −2.62, p<.01,d= 0.29] than did men. These find-
ings replicate the reliable sex difference demonstrated inmuch
of the disgust literature over the last several decades: women
exhibit significantly higher levels of disgust than do men (see
Al-Shawaf et al. 2018 for a review and novel hypotheses).
Similarly, sex differences in desire for short-term
mating [pre-disgust-induction: t(301) = 13.07, p< .001,
d= 1.4; post-disgust-induction: t(286) = 13.31,
p< .001, d= 1.43] corroborated the robust and well-
replicated finding that short-term mating looms larger
in men’s psychology than in women’s(Buss2015;
Buss and Schmitt 1993; Lippa 2009).
Evolutionary Psychological Science
Interaction: Disgust Manipulation * Experimental Condition
We conducted a mixed-model ANOVA with one within-
subjects factor (interest in short-term mating: pre- and post-
manipulation) and one between-subjects factor (experimental
condition) in order to assess the effect of the disgust manipu-
lation on desire for short-term mating and to determine wheth-
er this effect differed according to experimental condition.
There was a statistically significant disgust manipulation ×
experimental condition interaction on short-term mating de-
sire, F(3, 332) = 19.47, p< .001, partial η
2
= .15, indicating
that there were differential effects of the disgust manipulation
across conditions.
Simple Effects of Disgust Manipulation
Before analyzing the simple effects of the disgust manipula-
tion across experimental condition, we checked for sex differ-
ences in the extent to which the disgust manipulation affected
desire for short-term mating. There were no sex differences in
change in desire for short-term mating in any of the experi-
mental conditions (all ps > .05), so we collapsed across sex.
Because our primary hypothesis was that inducing disgust –
particularly sexual disgust –leads to a decrease in desire for
short-term mating, we began by analyzing the simple effects of
the experimental manipulations. As expected, participants ex-
posed to the sexual disgust stimuli exhibited a significant reduc-
tion in desire for short-term mating, F(1, 85) = 79.24, p< .001,
partial η
2
= .48. The participants in the pathogen disgust condi-
tion also exhibited a reduction in short-term mating desire: F(1,
85) = 24.51, p< .001, partial η
2
= .22. The threatening control
group also experienced a dip in desire for short-term mating,
F(1, 82) = 9.72, p< .01, partial η
2
= .11. As expected, there was
no change in desire for short-term mating in the neutral control
group, F(1, 80) = .86, p= .36, partial η
2
=.01.
In order to test the magnitude of the reduction across
conditions, we computed a pre-post manipulation differ-
ence score for each experimental condition. A one-way
ANOVA indicated that, as predicted, there was a signif-
icant difference in the magnitude of the reduction in
short-term mating desire across conditions, F(3, 332) =
19.47, p< .001, partial η
2
= .15. Post-hoc tests revealed
that individuals in the sexual disgust condition experi-
enced the greatest reduction in short-term mating desire
(all post-hoc tests reported in this manuscript are Tukey
HSDs). This decline was greater than that in the patho-
gen disgust condition (difference between means = 1.81,
SE = .49, p= .001, the threatening control condition
(difference between means = 2.51, SE = .47, p< .001),
and the neutral control condition (difference between
means = 3.14, SE = .45, p<.001; see Fig. 1).
Simple Effects of Experimental Condition
Prior to the manipulation, there were no differences between
conditions in desire for short-term mating, F(3, 341) = .87, ns,
partial η
2
= .01. After the manipulation, there was a significant
difference between groups in desire for short-term mating,
F(3, 333) = 10.06, p< .001, partial η
2
= .08. Post-hoc tests
revealed that the sexual disgust group had the lowest desire
for short-term mating—lower than the pathogen disgust group
(difference between means = 2.04, SE = .71, p<.05), the
threatening control group (difference between means = 3.61,
SE = .76, p< .01), and the neutral control group (difference
betweenmeans=3.87,SE=.79,p< .01). There were no other
post-manipulation–between-group differences in short-term
mating desire (all ps > .05).
Table 1 Means, standard
deviations, and effect sizes for the
sex differences in experiment 1
Disgust subscale (TDDS) Men mean (SD) Women mean (SD) Cohen’sd
Sexual 24.60 (9.51) 37.04 (8.20) 1.40
Moral 31.51 (9.71) 34.18 (8.97) .29
Pathogen 32.82 (8.19) 36.53 (7.17) .48
Current desire for short-term mating
Pre-disgust induction 14.78 (5.33) 8.57 (3.30) −1.39
Post-disgust induction 13.23 (5.32) 7.02 (3.05) −1.41
-4
-3
-2
-1
0
Control Group Threatening Control Pathogen Disgust Sexual Disgust
Experimental condition
Change in short-term mating desire
Experiment 1: Change in short-term mating desire across conditions
Fig. 1 Change in desire for short-term mating across conditions in ex-
periment 1. The sexual disgust condition experienced the greatest reduc-
tion in desire for short-term mating. Bars represent pre-post manipulation
difference scores and error bars represent 95% confidence intervals
Evolutionary Psychological Science
Discussion
The results of experiment 1 support the central hypothesis that
inducing sexual disgust reduces short-term mating desire. By
including both pre- and post-measures of short-term mating de-
sire, we were able to directly measure change in desire for short-
term mating as a consequence of disgust induction. This analysis
revealed several findings that support the primary hypothesis of
this study: a) the groups did not differ in their desire for short-
term mating before the manipulation, but did differ after the
manipulation, b) the sexual disgust group showed the strongest
decline in desire for short-term mating, c) the neutral control
group showed no change in desire for short-term mating, and
d) post-hoc tests revealed that after disgust induction, the sexual
disgust group exhibited lower desire for short-term mating than
all three other groups, and none of the other groups differed in
their desire for short-term mating. It is interesting to note both the
power of sexual disgust to reduce short-term mating desire, as
well as the finding that pathogen disgust primes and threatening
primes also have an impact on short-term mating desire. This
suggests that inducing other negative emotions—perhaps those
that signal pressing adaptive problems—canalsohaveaneffect
on short-term mating desire, but that the effect of sexual disgust is
especially powerful.
Experiment 2: the Effect of Different Modes
of Disgust Induction on Desire for Short-Term
Mating
We sought to replicate this central finding in an independent
study with a new sample, different experimental conditions in-
volving additional perceptual modalities, and novel stimuli. We
conducted a second study in which we included five experimen-
tal conditions: visual sexual disgust, visual pathogen disgust,
olfactory pathogen disgust, text-based pathogen disgust, and a
threatening control. Our central hypothesis was the same as that
of experiment 1: inducing disgust—especially sexual disgust—
should cause a decline in desire for short-term mating.
Method
Participants
Three hundred fifty participants (153 men, 194 women, 3
unreported; M
age
=18.83, SD
age
= 1.16, age range: 17–
26 years) were recruited from the psychology subject pool at
The University of Texas at Austin. Sample size was deter-
mined before any data analysis. No participants from experi-
ment 1 participated in experiment 2. Participants arrived at the
laboratory, provided informed consent to participate in the
study, and were escorted by a researcher to a private room
where they completed the experiment. Participants received
partial course credit for their participation and were debriefed
upon completion.
Design
Similar to experiment 1, experiment 2 was a 2 × 5 mixed-
design ANOVA with one within-subjects factor (interest in
short-term mating: pre- and post-manipulation) and one
between-subjects factor (experimental condition: visual sexu-
al, visual pathogen, olfactory pathogen, text-based pathogen,
and threatening control).
Participant breakdown by experimental condition was as
follows: sexual 69 (34 males), pathogen 67 (24 males), olfac-
tory 67 (30 males), text-based 65 (36 males), and threatening
control 70 (25 males).
The two new conditions in this experiment were the text-
based pathogen condition and the olfactory pathogen condi-
tion. The text-based group read a popular internet story about
parasitic invertebrate infection whose text was modified for
this experiment in order to induce pathogen disgust. We in-
duced pathogen disgust in the olfactory group with the use of
Liquid ASS®(Liquid ASSets Novelties, LLC, USA), a spray
that mimics the odor of putrid feces. As in experiment 1,
participants completed the same scale measuring desire for
short-term mating, underwent the disgust manipulation, com-
pleted the short-term mating scale again, and finally complet-
ed the instrument designed to assess current disgust.
We retained the threatening control because the threatening
control group in experiment 1 experienced a dip in desire for
short-term mating. If we wish to establish that inducing dis-
gust causes a significant decline in desire for short-term mat-
ing over and above aversive states in general, then the more
appropriate and more conservative control condition is that of
the threatening prime.
The disgust induction procedure was somewhat different in
the olfactory pathogen condition. In this condition, at the same
point in the survey at which the manipulations were intro-
duced into the other conditions, the survey prompted the par-
ticipant to step outside of the private laboratory room and call
the experimenter. The experimenter then entered the partici-
pant’s room with a rag that had been sprayed twice in the same
spot with Liquid ASS®. The experimenter held out the rag
and asked participants to take two deep breaths with their nose
in the spot where the smell had been sprayed. When this
procedure was completed, the experimenter stepped out of
the room again, permitting the participant to complete the
experiment in privacy.
Materials
Participants completed the same instruments as in experiment
1, including the short-term mating scale and the measure of
current disgust.
Evolutionary Psychological Science
Results
Manipulation Check
As in experiment 1, we tested the efficacy of our disgust ma-
nipulation by comparing the post-manipulation disgust levels
of our five groups. Disgust means and standard deviations for
each experimental condition were as follows: sexual 11.539
(SD = 3.14), pathogen 11.82 (SD = 2.87), olfactory 10.81
(SD = 3.64), text-based 10.81 (SD = 3.64), and threatening
control 10.92 (SD = 3.48). A one-way ANOVA confirmed
that disgust levels did not differ significantly between condi-
tions, F(4, 333) = 1.22, p=.30, partial η
2
=.014.
Descriptive Statistics
Tab le 2presents experiment 2 means and standard deviations
for the three disgust scales (Cronbach’sα:moral=.89,sexu-
al = .88, pathogen = .79) and the researcher-generated scale
indexing current desire for short-term mating (pre-manipula-
tion α= .71, post-manipulation α=.70).
Sex differences in disgust were consistent with experiment
1 and with previous research. Women in the current study
exhibited stronger sexual disgust [t(328) = −12.83, p<.001,
d= 1.41] and pathogen disgust [t(290) = −7.81, p< .001,
d= .87]. The sex difference in moral disgust, though in the
expected direction, did not reach significance [t(301) = −1.53,
p=.1, d= .17]. As in experiment 1, sex differences in desire
for short-term mating [pre-disgust-induction t(266) = 12.30,
p< .001, d= 1.36; post-disgust-induction t(260) = 10.51,
p< .001, d= 1.16] again corroborated the well-established
finding that men are more inclined toward short-term mating
than are women (Schmitt 2003).
Interaction: Disgust Manipulation * Experimental Condition
As in experiment 1, we conducted a mixed analysis of variance
(ANOVA) with one within-subjects factor (interest in short-
term mating: pre- and post-manipulation) and one between-
subjects factor (experimental condition) in order to assess the
effect of the disgust manipulation on desire for short-term
mating and to determine whether this effect differed by exper-
imental condition. As in experiment 1, there was a significant
interaction between experimental condition and the disgust
manipulation, F(4, 347) = 6.73, p< .001, partial η
2
= .07, indi-
cating that the effect of the manipulation differed across
conditions.
Simple Effect of the Disgust Manipulation
To unpack this significant interaction, we again analyzed the
simple effects of disgust manipulation and experimental con-
dition separately. As in experiment 1, these effects did not
differ by sex, so we provide the results of these tests for men
and women together.
Because our primary hypothesis was that inducing disgust—
especially sexual disgust—should lead to a decrease in desire for
short-term mating, we began with the simple effects of the dis-
gust manipulations. As in experiment 1, there was a significant
decline in desire for short-term mating in the sexual disgust
group, F(1, 69) = 63.16, p< .001, partial η
2
= .48, and in the
visual pathogen group, F(1, 69) = 16.73, p< .001, partial
η
2
= .20. The olfactory and text-based disgust groups also exhib-
ited declines in short-term mating desire [olfactory F(1,70) =
23.86, p< .001, partial η
2
=.25, text-based F(1, 69) = 26.22,
p< .001, partial η
2
= .28]. The threatening control group, on
the other hand, showed no change in desire for short-term mat-
ing, F(1,70) = 2.81, ns,partialη
2
=.04.
In order to test the magnitude of the reduction in short-term
mating desire across condition, we computed a pre-post ma-
nipulation difference score for each experimental condition. A
one-way ANOVA indicated that, as predicted—and replicat-
ing the findings of experiment 1—there was a significant dif-
ference in the magnitude of the reduction in short-term mating
desire across conditions, F(4, 347) = 6.73, p< .001, partial
η
2
= .07. Post-hoc tests revealed that individuals in the sexual
disgust condition experienced a greater reduction in short-
term mating desire than those in the visual pathogen disgust
condition (difference between means = 1.81, SE = .55,
p= .011), the text-based pathogen condition (difference be-
tween means = 1.56, SE = .55, p< .05), and the threatening
control condition (difference between means = 2.79,
SE = .55, p< .001) (Fig. 2).
Table 2 Means, standard
deviations, and effect sizes for the
sex differences in experiment 2
Disgust subscale (TDDS) Men mean (SD) Women mean (SD) Cohen’sd
Sexual 22.50 (8.52) 34.94 (9.09) 1.41
Moral 29.52 (10.23) 31.15 (9.01) .17
Pathogen 30.97 (7.25) 36.94 (6.40) .87
Current desire for short-term mating
Pre-disgust induction 15.08 (5.04) 9.09 (3.65) −1.36
Post-disgust induction 12.76 (5.28) 7.49 (3.73) −1.16
Evolutionary Psychological Science
Simple Effects of Experimental Condition
We followed this with an analysis of the simple effect of con-
dition. As in experiment 1, there were no differences between
groups in desire for short-term mating before the onset of the
manipulation, F(4, 351) = 1.91, ns, partial η
2
= .02. After the
manipulation, however—and replicating the findings of ex-
periment 1—the groups differed in desire for short-term mat-
ing, F(4, 351) = 3.38, p=.01, partialη
2
= .04. Post-hoc tests
revealed that the sexual disgust group had the lowest desire for
short-term mating—lower than the threatening control group
[difference between means = 2.34, SE = .80, p= .03] and the
olfactory group [difference between means = 2.82, SE = .85,
p= .01]. There were no other between-group differences in
desire for short-term mating (all ps > .05).
Discussion
The results of experiment 2 cleanly replicate those of experi-
ment 1, providing empirical support for the hypothesis that
inducing disgust—especially sexual disgust—leads to a de-
cline in desire for short-term mating. This is especially inter-
esting given that the manipulation check revealed only non-
significant differences in disgust between groups. As in ex-
periment 1, the central findings in experiment 2 provide sev-
eral pieces of evidence in support of our primary hypothesis:
a) the five groups did not differ in their desire for short-term
mating before the manipulation, but did differ after the manip-
ulation, b) the sexual disgust group showed the strongest de-
cline in desire for short-term mating (significantly stronger
than the visual pathogen group, the text-based group, and
the threatening control group), c) the threatening control
group showed no change in desire for short-term mating,
and d) post-hoc tests revealed that after disgust induction,
the sexual disgust group exhibited lower desire for short-
term mating than the threatening control group and the
olfactory disgust group. These results support our primary
hypothesis and show that the results of experiment 1 replicate
robustly across independent samples with modified methods.
General Discussion
The logic underlying our central hypothesis comes from a task
analysis of short-term mating strategies. Since short-term mating
involves casual sex, sex with multiple partners, and sex after brief
periods of acquaintance, those with a strong proclivity for short-
term mating may be less able to implement their preferred mating
strategy in the presence of high levels of sexual disgust. This
reasoning suggests the hypothesis that short-term mating mech-
anisms calibrate sexual disgust levels in order to facilitate the
implementation of those strategies (Al-Shawaf et al. 2015c).
This broad hypothesis gives rise to two specific hypotheses.
The first is that individuals oriented toward short-term mating
should have lower levels of sexual disgust than their less short-
term-oriented counterparts. We have found empirical support for
this hypothesis in two independent studies (Al-Shawaf et al.
2015c). The second hypothesis is the one we advance in this
paper: because low sexual disgust is an important component
of short-term mating strategies, experimentally inducing sexual
disgust should cause a decline in desire for short-term mating.
In both studies, inducing disgust caused a decline in desire
for short-term mating, and this decrease was most pronounced
for those in the sexual disgust group. This suggests that ex-
perimentally inducing disgust has the capacity to inhibit short-
term mating, and that the inhibitory effect of sexual disgust is
particularly strong. In both studies, our groups did not differ in
desire for short-term mating before the disgust manipulation,
but did differ after it, providing 1) evidence for the efficacy of
our disgust induction procedures and 2) evidence that the
findings presented here are not artifacts of baseline differences
between groups in their desire for short-term mating. Together
with the finding that individuals with a stronger proclivity for
short-term mating have lower levels of sexual disgust (Al-
Shawaf et al. 2015c), the current results bolster the hypothesis
that reduced levels of sexual disgust constitute an important
but previously undiscovered design feature of short-term mat-
ing strategies.
Limitations and Future Directions
Our use of experimental methodology—and especially of a
repeated-measures design—enables us to make causal infer-
ences about the impact of sexual disgust on short-term mating
desire. Nonetheless, providing convergent evidence using
new stimuli, different methodologies, and novel samples
would buttress support for the hypothesis presented here and
enhance our confidence in the veridicality of our findings.
-4
-3
-2
-1
0
Threatening
Control
Visual
Pathogen Disgust
Text-based
Pathogen Disgust
Olfactory
Pathogen Disgust
Sexual
Disgust
Experimental condition
Change in short-term mating desire
Experiment 2: Change in short-term mating desire across conditions
Fig. 2 Change in desire forshort-term mating across conditions in exper-
iment 2. The sexual disgust condition experienced a greater decline in
desire for short-term mating than the visual pathogen disgust condition,
text-based pathogen disgust condition, and threatening control condition.
Bars represent pre-post manipulation difference scores and error bars
represent 95% confidence intervals
Evolutionary Psychological Science
Our methodology presents two potential limitations. First, in
experiment 1, the neutral control group was not exposed to any
slideshow. An alternative would be to present a neutral
slideshow, as in Mortensen et al. (2010). In this way, the differ-
ence between the neutral condition and other conditions would
be isolated to the content of the slideshow. Second, in experiment
2, our induction of olfactory pathogen disgust required an exper-
imenter to enter the room, a feature that was not present in the
other experimental conditions. Although we think it implausible
that it was the entry of the experimenter rather than the rag with
the offensive odor that was responsible for inducing disgust, a
future design that enables the presentation of the offensive odor
without the presence of the experimenter would be ideal.
The experiments presented are necessarily tied to the way
we operationalized our constructs. It remains to be seen, for
example, whether future experiments will yield the same pat-
tern of results if we employ different images in the pathogen
and sexual conditions, different odors in the olfactory condi-
tion, or different stories in the text-based condition.
Conducting numerous experiments with varying stimuli is a
good way to detect systematic patterns in the results: if differ-
ent stimulus sets reliably reveal similar patterns as the ones we
report here, that points to the robustness and generalizability
of the phenomenon and constitutes good evidence for the
hypothesis under investigation.
An important next step will be to examine the cross-
cultural universality of this phenomenon, as we expect the
relationship between short-term mating strategies and disgust
to be universal. The behavioral outputs, facial displays, and
other outward expressions may vary across individuals and
cultures, but we expect uniformity in the underlying psycho-
logical mechanisms responsible for short-term mating and its
relationship to sexual disgust. Cross-cultural tests also afford
the opportunity to examine variables such as prevalence of
sexually transmitted infections and local pathogen density,
and assess their hypothesized impact on disgust and mating
strategy (see Schaller and Murray 2008).
The hypothesis that short-term mating is partly responsible
for calibrating sexual disgust also points toward a longitudinal
test. Humans have been hypothesized to experience shifts
in mating strategy as a function of contextual or organis-
mic conditions such as operational sex ratio, longitudinal
changes in mate value, as well as life events such as
entering a new romantic relationship, having a child, or
emerging from a break-up (e.g., Burnham et al. 2003;
Buss and Greiling 1999; Gettler et al. 2011;Mazurand
Michalek 1998;McIntyreetal.2006;Schmitt2005). A
valuable test would be to investigate whether these shifts
in mating strategy are accompanied by concomitant shifts
in sexual disgust. For instance, having offspring may up-
regulate sexual disgust, andemergingfromabreak-up
may downregulate sexual disgust to facilitate a person’s
re-entry into the mating market.
Another important future direction involves priming partici-
pants with mating mindsets. If low levels of sexual disgust are
needed to facilitate a short-term mating strategy, then successful-
ly priming a short-term mating mindset may cause a temporary
downregulation of sexual disgust (see Ariely and Loewenstein
2006; Borg and de Jong 2012; Stevenson et al. 2011).
A final limitation involves the self-report nature of our mea-
sure of short-term mating interest. Although studies show that
self-report measures predict behavioral measures fairly well
(Glasman and Albarracin 2006), future studies would benefit
from including behavioral, endocrinological, and psychophysio-
logical measures. Convergent evidence from multiple data
sources is always more compelling, and paints a more compre-
hensive picture.
Conclusions
The findings presented here support the hypothesis that experi-
mentally inducing sexual disgust causes a reduction in desire for
short-term mating—an effect found for both men and women.
These findings provide corroborative experimental support for
the broader hypothesis that low levels of sexual disgust facilitate
the implementation of short-term mating strategies. Evidence is
now accumulating—from experimental and non-experimental
studies using a variety of different types of stimuli and disgust
induction procedures—that reduced levels of sexual disgust are
an important, previously undiscovered design feature of short-
term mating strategies (Al-Shawaf et al. 2015c). This growing
body of evidence illuminates specialized design features of the
psychology of short-term mating and reveals an important link
between human mating and the emotion of disgust.
Compliance with Ethical Standards
Conflict of Interest On behalf of all authors, the corresponding author
states that there is no conflict of interest.
Publisher’sNote Springer Nature remains neutral with regard to juris-
dictional claims in published maps and institutional affiliations.
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