Disgust as a motivator of avoidance of spiders

Disgust as a motivator of avoidance of spiders

Sheila R. Woody*, Carmen McLean1, Tammy Klassen

Department of Psychology, University of British Columbia, 2136 West Mall,

Vancouver, BC, Canada V6T 1Z4

Received 20 January 2004; received in revised form 7 April 2004; accepted 9 April 2004

Abstract

Individuals with small animal phobias show elevated general disgust sensitivity, and

spider phobics often endorse both fear and disgust in response to a spider. Some researchers

have argued that the link between disgust and fear of small animals is spurious. On the other

hand, disgust may play a functional role, as might any negative emotion that is strongly

stimulus-bound, in which escape or avoidance is negatively reinforced. It is therefore

important to clarify whether disgust has a functional or epiphenomenal role in avoidance of

feared stimuli. The present study examined the degree to which disgust motivates

avoidance of spider-related stimuli using a series of behavioral avoidance tests comparing

a harmless tarantula, a pen that had come in contact with the spider, and a clean pen. Peak

disgust was a stronger predictor than anxiety of avoidance of both the spider and the

‘‘contaminated’’ pen.

# 2004 Elsevier Inc. All rights reserved.

Keywords: Phobia; Disgust; Anxiety; Avoidance

Research on phobias has typically focused on fear, despite the observation that

anxiety likely involves an aggregate of several emotions with fear being the

principal feeling (Bartlett & Izard, 1972; Izard, 1972). Like all subjective events,

phobic reactions probably involve several emotions that intersect and blend to

form the felt experience and to motivate behavioral intentions. An increasing

body of research indicates that disgust may be an important feature of some

phobias, particularly those of small animals like snakes and spiders. This study

Anxiety Disorders

19 (2005) 461–475

* Corresponding author.

E-mail address: [email protected] (S.R. Woody).1 Carmen McLean is now at the Department of Psychology, University of Nabraska–Lincoln.

0887-6185/$ – see front matter # 2004 Elsevier Inc. All rights reserved.

doi:10.1016/j.janxdis.2004.04.002

was designed to use behavioral assessment to better understand the nature of the

role of disgust in avoidance of spiders.

Disgust in the context of anxiety disorders has received increased research

attention in the past few years. General disgust sensitivity is moderately predictive

of general fearfulness (Davey, Forster, & Mayhew, 1993) and more strongly

correlated with fear of repulsive animals (Tucker & Bond, 1997). Snake-fearful

participants show more disgust sensitivity than do low fear respondents (Klieger

& Siejak, 1997), and girls and women with spider phobias show the same pattern

(de Jong, Andrea, & Muris, 1997; Merckelbach, de Jong, Arntz, & Schouten,

1993). Disgust sensitivity is also higher among individuals with blood injury

phobia (Sawchuk, Lohr, Westendorf, Meunier, & Tolin, 2002). Thorpe and

Salkovskis (1998), in contrast, found no differences in disgust sensitivity between

groups of participants with spider phobia, other phobias, and no clinical disorders.

Most studies have shown that individuals with some specific phobias or strong

fears endorse higher levels of disgust sensitivity, defined as a propensity to feel

disgusted in response to a wide range of stimuli. An important question is whether

(state) disgust features as a specific part of the phobic emotional experience.

When disgust is provided as a potential response, spider phobics often endorse

fear and disgust in equal measure (Sawchuk et al., 2002; Thorpe & Salkovskis,

1998; Tolin, Lohr, Sawchuk, & Lee, 1997). Tolin et al. (1997) reported that spider

phobics rated photographs of spiders as both fearful and disgusting. Participants

were just as likely to endorse fear statements such as, ‘‘This picture makes me feel

like I am in danger’’ as they were to endorse disgust statements such as, ‘‘This

picture makes me feel like I might be contaminated or infected.’’ Ratings of fear

and disgust are strongly correlated in most studies of small animal fears (Sawchuk

et al., 2002; Thorpe & Salkovskis, 1998; Woody & Tolin, 2002).

Although disgust seems to be related to various self-report measures of fear,

Thorpe and Salkovskis (1998) argue that the relationship may be correlational,

rather than functional. Thorpe and Salkovskis (1998) argue that content overlap

may be responsible for the observed correlation in questionnaire studies. Disgust

sensitivity questionnaires often include items about other leggy creatures to which

spider phobics may be sensitized. However, respondents with specific phobias

report elevated disgust responding to a wide range of stimuli across domains

including spoiled food, bodily products, and offensive odors (de Jong & Merck-

elbach, 1998). A more compelling argument offered by Thorpe and Salkovskis

(1998) is that phobic fear simply amplifies disgust toward objects that most people

already find to be disgusting.

On the other hand, fear and disgust both motivate behavioral withdrawal, so a

functional role for disgust in animal phobias is plausible. Fear motivates a desire

to seek safety through escape or avoidance, which in turn reduces fear, thus

reinforcing avoidance (Mowrer, 1960). Avoidance is central to the impairment

associated with most anxiety disorders, and Mowrer’s two-factor theory, although

perhaps no longer accepted in its entirety, remains integral to the theoretical basis

of behavioral interventions. Disgust may function similarly to fear, as might any

462 S.R. Woody et al. / Anxiety Disorders 19 (2005) 461–475

negative emotion that is strongly stimulus-bound, because escape or avoidance of

the stimulus terminates the negative emotion. It is therefore important to clarify

whether disgust has a functional or epiphenomenal role in avoidance of feared

stimuli.

Studies examining the link between disgust and fear have often used ques-

tionnaire methods, which do not allow an exploration of the link between these

emotions and behavior. Only a few studies have thus far investigated the role of

disgust in fearful avoidance using behavioral assessment methods. Working

within the disease avoidance model of disgust, Mulkens, de Jong, and Merck-

elbach (1996) invited female participants to eat a cookie that a spider had walked

across. Among nonphobic women, 71% eventually ate the cookie, but only 25%

of the phobic women did so. Such avoidance was not due to general fastidious-

ness, as there were no differences between groups on their behavior or affect

related to drinking tea from dirty cups. de Jong and Muris (2002) found similar

results in a questionnaire study of 10–14-year-old spider phobic girls, who rated

their eagerness to eat their favorite candy bar as significantly dampened if a spider

had walked across it, even if the bar remained in its packaging. Nonphobic girls

were also less enthusiastic about a chocolate bar that a spider had come in contact

with, but the effect was significantly smaller.

Approaching the research question in a unique way, Klieger and Siejak (1997)

used two behavioral avoidance tasks to investigate why people who report high

fear of snakes do not always avoid. Participants first engaged in a traditional

behavioral avoidance task (BAT) in which they were asked to approach a

terrarium containing a small snake and an oversize plastic pen. The experimenter

then transferred the snake out of the terrarium while participants were out of the

room. Participants were invited to return to the testing room to remove the pen

from the terrarium. Contrary to expectation, high and low fear participants were

indistinguishable in their response to the contaminated pen. Although the study

presents a good method for studying disgust-motivated avoidance of phobic

stimuli, it was inconclusive for several reasons. First, avoidance of the snake was a

primary interest, but the BAT was not challenging enough to elicit any avoidance

from any participant—including the high fear participants. Of greater concern for

a study on disgust, participants wore protective gloves when removing the pen,

which would clearly eliminate fear of contamination.

Disgust may be an important aspect of spider phobia in that it has the potential

to motivate avoidance. On the other hand, the experience of disgust may simply

represent a negative evaluation of the feared stimulus, an evaluation perhaps

heightened by physiological arousal (Thorpe & Salkovskis, 1998). The present

study aims to examine the degree to which disgust motivates avoidance of spider-

related stimuli using a method similar to that used by Klieger and Siejak (1997).

Modifications include a more demanding BAT that invites participants who are

high or low in fear of spiders to touch a harmless tarantula for 3 s. A second task

provides an opportunity for a high level of engagement with a spider-contami-

nated pen: rolling the pen on a cracker before taking a bite of the cracker. Spider

S.R. Woody et al. / Anxiety Disorders 19 (2005) 461–475 463

fearful participants were certainly expected to avoid the spider more than the

nonfearful participants did, but they were also expected to avoid the spider-

contaminated pen despite the absence of danger in this BAT.

1. Method

1.1. Participants

One hundred fifteen undergraduates (mean age ¼ 20:3 � 3:17) who had

previously rated themselves as high or low in fear of spiders volunteered to

participate in a study on ‘‘emotional correlates of approach and avoidance.’’

Participants received a small incentive involving either money ($5) or partial

psychology course credit. Fifty-five of these students (30 were female) reported

‘‘much’’ or ‘‘very much’’ fear of spiders, and 60 (30 female) reported they were

‘‘not at all’’ or ‘‘a little’’ afraid of spiders. To reduce selection and response biases,

participants were not informed as to why they were being recruited (i.e., their

previously endorsed level of spider fear).

1.2. Measures

1.2.1. Questionnaires

The spider item of the animal subscale of the Fear Survey Schedule (Wolpe

& Lang, 1964) served as a screening measure. Items on this nine-item subscale

assess fear of specific animals on a five-point Likert-type scale ranging from

‘‘not at all’’ to ‘‘very much.’’ The Fear Survey Schedule was designed as a

series of single item scales, and we were interested only in the spider item.

Other items from the animal subscale were included to decrease salience of the

spider item.

The Disgust Scale (DS) (Haidt, McCauley, & Rozin, 1994) is an index of

sensitivity to disgust-eliciting stimuli across a broad range of domains: food,

animals, body products, sex, body envelope violations, death, and hygiene. This

32-item measure includes both true/false items and 0–2 ratings of how disgusting

particular experiences would be, such as, ‘‘You see maggots on a piece of meat in

an outdoor garbage pail.’’ The scale developers report good internal consistency

and evidence of discriminant validity (Haidt et al., 1994). Rozin, Haidt, McCau-

ley, Dunlop, and Ashmore (1999) demonstrated a relatively strong relationship

(jrj ¼ :51) between Disgust Scale responses and disgust behavior across a set of

32 disgust-related behavioral tasks.

The Anxiety Sensitivity Index (ASI) is a 16-item scale measuring danger

beliefs and feared social and somatic consequences of anxiety symptoms. The

ASI has demonstrated good reliability and shows predictive validity for devel-

opment of subsequent panic attacks and anxiety disorders among university

students (Maller & Reiss, 1992; Peterson & Heilbronner, 1987).


The Fear of Spiders Questionnaire (FSQ) (Szymanski & O’Donohue, 1995) is

an 18-item measure that assesses participants’ avoidance of and fear of harm from

spiders. Respondents rate their degree of agreement with statements such as, ‘‘If I

came across a spider now, I would leave the room.’’ The FSQ has good internal

consistency, satisfactory test-retest reliability and adequate convergent validity; it

discriminates between phobics and nonphobics as well as being sensitive to

treatment change (Szymanski & O’Donohue, 1995). The FSQ was included as an

indicator of severity of fear of spiders.

1.2.2. Behavioral avoidance tasks (BATs)

Behavioral avoidance tasks (BATs) generally measure self-reported affect

and degree of avoidance in response to specific stimuli. For this study, BATs

with three different stimuli were used: a spider, a pen that had been contami-

nated by a spider, and a new clean pen. For each task, participants were asked

to approach the stimulus as closely as possible, but they were reminded they

could stop at any point. Immediately following the task, participants were

prompted to use 0–100 scales to provide a rating of their peak anxiety

(‘‘nervous’’) and peak disgust (‘‘grossed out’’) during the task. There was

no time limit for the task.

1.2.2.1. Spider BAT. A BAT involving a spider is a common behavioral

assessment in studies of spider phobia (e.g., Ost, 1996; Rodriguez, Craske,

Mineka, & Hladek, 1999). The spider used in this task was a large Honduran

Curly tarantula that was 12 cm long with legs outstretched. This spider was a

particularly useful stimulus for this purpose because she was alarming in

appearance (being both large and rather hairy) but not dangerous, and she

moved relatively slowly. Participants entered the testing room where the spider

was resting in a glass cage about 3 m from the door. The glass aquarium was clean

and empty except for the spider and a brand new ballpoint pen. The steps of the task

involved approaching the cage, then touching the outside walls of the aquarium,

removing the aquarium top, touching the inside walls and floor of the aquarium,

and finally touching the spider with one finger for 3 s. Participants were explicitly

reminded they could escape the task at any point.

After explaining the task in a separate room, the experimenter took the

participant to the door of the testing room and invited the participant to open

the door to begin the task. When participants indicated they did not want to

approach the spider further (or when they completed the final step by touching the

spider), the experimenter obtained ratings of peak anxiety and disgust during the

task and guided the participant out of the testing room.

1.2.2.2. Contaminated Pen BAT. The purpose of this test was to examine affect

and avoidance using a spider-related stimulus that clearly has no threat value. The

participant was given an opportunity to engage with a pen the spider had touched.

The contamination BAT was modified from the procedure used by Klieger and


Siejak (1997). Recall that the testing cage for the Spider BAT had a new ballpoint

pen in addition to the spider. The experimenter, accompanied by the participant,

entered the spider testing room and removed the pen from the aquarium with

wooden tongs to limit contamination to that associated with the spider. The

experimenter placed the pen on a new paper plate, and both the experimenter and

the participant went into a different room to continue with the task.

The Contaminated Pen BAT involved increasing degree of contact with the

pen. Participants started by simply sitting across the table from the pen on the

plate. The steps involved in the BAT included touching the pen with one finger and

then with both hands. If participants wished to continue, they were asked to use

the pen to write their name on the paper plate and then touch the pen to their head

and their closed lips and finally to eat a cracker after rolling the pen across it. As

with the Spider BAT, the experimenter reminded participants they were free to

stop the task at any point and prompted participants to provide verbal ratings of

peak anxiety and disgust immediately following the task. The Contaminated Pen

BAT and the Spider BAT were counterbalanced.

1.2.2.3. Clean Pen BAT. One additional BAT was included as a check on whether

the steps of the Contaminated Pen BAT would be generally acceptable to

participants, if the spider had not touched the pen. This BAT was identical to

the Contaminated Pen BAT except that no mention was made of the spider. Again

using wooden tongs, the experimenter removed a new pen from a box of pens and

asked the participant to engage in the steps described above for the Contaminated

Pen BAT, including eating a cracker after rolling the pen across it.

1.3. Procedure

Participants high or low in fear of spiders were recruited to the study on the

basis of their responses to the ‘‘spider’’ item of the Fear Survey Schedule, which

was completed on a voluntary basis in the hallways of a university classroom

building. Appropriate respondents who had indicated their willingness to be

contacted for psychology research were contacted and scheduled for an appoint-

ment without reference to the screening criteria (i.e., participants did not know

how they were deemed to be eligible). During informed consent, the experimenter

provided definitions of anxiety and disgust and explained the use of the 0–100

scales. The experimenter explained that the participant was in complete control of

how long he or she decided to engage in each task. In order to reduce social

pressure to complete each task, the experimenter stated that although there was no

actual danger in any of the situations, we expected few people would want to fully

complete all tasks.

Participants were randomly assigned to one of a series of counterbalanced

orders of conditions. The questionnaire measures of disgust sensitivity, anxiety

sensitivity, and spider fear were administered either at the outset or the conclusion

of the experiment. The order of questionnaires was also counterbalanced, as was


the order of the Spider BAT and the two pen BATs. The Clean Pen BAT always

preceded the Contaminated Pen BAT to better assess the acceptability of a clean

pen (with no associations with spiders) being rolled across food before con-

sumption. The BAT procedures were carefully planned so that the experimenter

did not interact with the spider in view of the participant to avoid modeling.

2. Results

The study involved three repeated measures conditions: Spider BAT, Con-

taminated Pen BAT and Clean Pen BAT. Dependent variables for each BAT were

peak disgust, peak anxiety, and degree of approach to the stimulus. Predictor

variables were previously endorsed fear level (dichotomized to high or low), Fear

of Spiders Questionnaire, Disgust Scale, and Anxiety Sensitivity Index.

Only three participants (all high spider fear) failed to fully complete the Clean

Pen BAT, indicating that even though a ballpoint pen is not a food implement,

participants did not reject food that it had touched. Participants generally reported

low anxiety on this task; 82% of them gave ratings less than 25 on the 0–100 scale.

Disgust was also relatively low on this task, as 66% of participants rated peak

disgust as less than 25. As avoidance of the Clean Pen was minimal, this BAT was

not considered further in the analyses.

Initial analyses showed that the homogeneity of error variance assumption of

analysis of variance was not met for any of the spider fear variables. Because this

violation has potentially serious effects in the case of unequal cells (Winer,

Brown, & Michels, 1991), cases were eliminated to achieve equal numbers across

cells as suggested by Tabachnick and Fidell (1996). Within-group outliers were

manually eliminated, and an additional 10 cases were randomly selected (by

computer) for removal to achieve equal cell sizes. The data presented in this report

involve the remaining cases: 25 participants in each cell of the 2 (fear groupÞ � 2

(gender) matrix.

2.1. Validity of fear group categorization

Given that the fear groups were selected on the basis of a single questionnaire

item, group differences were examined on other indicators of spider fear as a test

of the validity of the fear group categorizations. The high fear group endorsed

significantly more fear on the Fear of Spiders Questionnaire (tð60:013Þ ¼ 10:273,

p < :001, d ¼ 2:13) and reported significantly more anxiety during the Spider

BAT (tð79:005Þ ¼ 8:749, p < :001, d ¼ 1:75). The degrees of freedom have been

adjusted because of unequal variances between the groups. Finally, significantly

fewer members of the high fear group (32%) completed all steps of the Spider

BAT than did members of the low fear group (76%; j ¼ �:441, p < :001). These

results suggest our categorization of fear groups was appropriate. Table 1 includes

the means and standard deviations for continuous variables.


2.2. Avoidance of the contaminated pen

If spider fearful participants are motivated by disgust in addition to (or instead

of) fear when avoiding the spider, then they should be more avoidant of the

contaminated pen than are the nonfearful participants. That is, avoiding full

contact with the pen can be taken as motivated by disgust of the spider rather than

fear because there was no possibility of being bitten by the pen. As discussed

earlier, the high fear participants were significantly more likely to avoid the

spider; they were also significantly more likely to avoid engaging in the full

behavioral task with the contaminated pen. Among the high fear participants, 40%

avoided the contaminated pen, whereas 20% of the low fear participants did so

(j ¼ �:218, p < :05).

2.3. Disgust and anxiety

Affect during the BATs was analyzed using a repeated measures MANOVA,

with the two BATs as a repeated factor and fear group as a between subjects factor.

Self-reported peak anxiety and disgust during the tasks were the dependent

measures. As expected, there was a significant main effect of fear group

(Fð2;97Þ ¼ 27:19, p < :001, partial Z2 ¼ :36), with the high fear group experien-

cing more intense anxiety (Fð1;98Þ ¼ 52:64, p < :001, partial Z2 ¼ :35) and

disgust (Fð1;98Þ ¼ 40:92, p < :001, partial Z2 ¼ :29) than the low fear

group. There was also a significant main effect for BAT (Fð2;97Þ ¼ 57:62,

p < :001, partial Z2 ¼ :54). The spider evoked significantly more anxiety

(Fð1;98Þ ¼ 109:59, p < :001, partial Z2 ¼ :53), but the difference for disgust

was weaker (Fð1;98Þ ¼ 3:79, p < :06, partial Z2 ¼ :04).

The task by group interaction was significant (Fð2;97Þ ¼ 9:52, p < :001, partial

Z2 ¼ :16) for both anxiety (Fð1;98Þ ¼ 18:37, p < :001, partial Z2 ¼ :16) and

Table 1

Means and standard deviations for low and high spider fear groups on behavioral avoidance test

(BAT) and questionnaire variables

Variable Low spider fear High spider fear

Mean S.D. Mean S.D.

Spider BAT Peak Anxiety 36.56a 29.82 79.30b 17.44

Spider BAT Peak Disgust 23.36a 30.56 63.76b 30.71

Contaminated Pen Peak Anxiety 20.00a 23.54 39.78b 28.75

Contaminated Pen Peak Disgust 25.34a 26.71 50.24b 29.88

Clean Pen BAT Peak Anxiety 8.44 11.84 10.76 17.29

Clean Pen BAT Peak Disgust 3.60 7.68 8.30 15.77

Fear of Spiders Questionnaire 26.70a 10.61 68.79b 26.13

Disgust Scale 14.98a 5.71 18.28b 5.71

Anxiety Sensitivity 19.36a 8.08 23.58b 10.68

Means with different subscripts are significantly different (p < :05).


disgust (Fð1;98Þ ¼ 6:84, p < :01, partial Z2 ¼ :07), although the pattern was

somewhat different for the two emotions. Fig. 1 shows the high fear group

reported significantly higher anxiety than did the low fear group, during both the

Spider BAT (tð79:005Þ ¼ �8:75, p < :001, d ¼ 1:75) and the Contaminated Pen

BAT (tð98Þ ¼ �3:76, p < :001, d ¼ 0:75). The spider task evoked more anxiety

than did the contaminated pen task, for both high fear (tð49Þ ¼ 9:87, p < :001,

d ¼ 1:40) and low fear (tð49Þ ¼ 4:65, p < :001, d ¼ 0:66) participants, but the

effect size was much larger among high fear participants. Fig. 2 shows the

comparable data for disgust. The high fear group reported more disgust of both the

spider (tð49Þ ¼ �6:59, p < :001, d ¼ 1:32) and the contaminated pen

(tð49Þ ¼ �4:39, p < :001, d ¼ 0:88) than did the low fear group. Low fear

participants reported a comparable degree of disgust for both the spider and

contaminated pen tasks (tð49Þ ¼ �0:59, p > :50, d ¼ 0:08), but high spider fear

participants reported significantly more disgust toward the spider than toward the

pen (tð49Þ ¼ 2:77, p < :01, d ¼ 0:39).

2.4. Predictors of avoidance

Sequential logistic regression analyses were used to examine predictors of

avoidance for both the spider and contaminated pen tasks. The following variables

were evaluated as predictors of failure to complete the behavioral task: peak

0

10

20

30

40

50

60

70

80

90

100

High Low

Spider Fear Group

Anx

iety

Lev

el

Spider AnxietyPen Anxiety

Fig. 1. Anxiety level during the Spider and Contaminated Pen BATs for participants high and low in

spider fear.


anxiety during the task, peak disgust during the task, Disgust Scale, and Anxiety

Sensitivity Index. State affect during the task (anxiety and disgust) was entered in

the first block of analysis, and the two trait questionnaires were entered together as

a second block.

2.4.1. Spider BAT

A test of the first block (peak anxiety and disgust during the task) against a

constant-only model was statistically reliable (w2ð2;n¼100Þ ¼ 22:63, p < :001)

indicating that the predictors, as a set, reliably distinguished between those

who completed the task and those who avoided. Prediction success was moderate,

with 70% of the completers and 63% of the avoiders correctly predicted. Table 2

shows regression coefficients, Wald statistics, and odds ratios for the analysis.

Only peak disgust was a significant predictor of avoidance, with an odds ratio of

1.021. The avoidance rate was 54% for the spider task, providing sufficient

avoidant behavior for the prediction analyses. The second block (questionnaires)

did not reliably add predictive value to the model (w2ð2;n¼100Þ ¼ 1:47, p > :40).

Prediction success declined slightly with the addition of the questionnaires, with

70% of the completers and 59% of the avoiders being correctly predicted.

2.4.2. Contaminated Pen BAT

The test of the first block (anxiety and disgust) against the constant-only model

was significant (w2ð2;n¼100Þ ¼ 32:39, p < :001). Prediction success was again

0

10

20

30

40

50

60

70

80

90

100

High Low

Spider Fear Group

Dis

gust

Lev

elSpider DisgustPen Disgust

Fig. 2. Disgust level during the Spider and Contaminated Pen BATs for participants high and low in

spider fear.


moderate, with 86% of the completers and 57% of the avoiders correctly

predicted. (70% of participants completed this task.) Table 2 shows regression

coefficients, Wald statistics, and odds ratios. As with the Spider BAT, peak disgust

was the only significant predictor of avoidance, with an odds ratio of 1.048. The

second block (questionnaires) again failed to reliably add predictive value to the

model (w2ð2;n¼100Þ ¼ 1:48, p > :40). Prediction success did improve slightly with

the addition of the questionnaires, with 86% of the completers and 60% of the

avoiders being correctly predicted.

The analyses were quite consistent across the two BATs. State disgust was a

significant predictor of avoidance, but state anxiety was not. Neither the DS nor

the ASI was significant predictors of avoidance if they were included in a model

that already included state anxiety and disgust. Although disgust sensitivity is

correlated with state disgust (r � :50 across the two BATs), the state measure was

a better predictor of behavioral avoidance in a specific situation.

2.4.3. Motivation for avoidance

An additional logistic regression analysis examined predictors of avoidance of

the contaminated pen among those participants who had avoided the spider. The

intention of this analysis was to discriminate individuals whose spider avoidance

may have been primarily motivated by disgust (as evidenced by avoidance of a

pen with no spider nearby) versus avoidance primarily motivated by fear (as

evidenced by willingness to use a pen touched by a spider as long as the spider was

no longer near). The results were similar to the analyses above.

Task order was included as the first block, but it failed to improve on the

prediction of the constant-only model (w2ð3;n¼100Þ ¼ 3:58, p > :30). Peak anxiety

and disgust during the Contaminated Pen BAT together represented a reliable set

of predictors of avoidance of the pen among those who had avoided the spider

(w2ð2;n¼100Þ ¼ 15:696, p < :001). Prediction success was relatively good, with 77%

of the completers and 83% of the avoiders correctly classified. (52% of those who

Table 2

Regression coefficients, wald statistics, and odds ratios for significant predictors of avoidance for the

spider and Contaminated Pen BATs

Variable B Wald p Odds ratio

Spider BAT Anxiety 0.01 1.21 .27 1.012

Disgust 0.02 5.04 .03 1.021

Constant �1.76 11.74 .001 0.172

Contaminated Pen BAT Anxiety �0.01 0.01 .94 0.999

Disgust 0.05 15.42 .001 1.048

Constant �2.92 27.30 .001 0.054

Pen (spider avoiders only) Anxiety 0.01 0.35 .55 1.010

Disgust 0.05 7.41 .01 1.050

Constant �2.25 4.34 .05 0.105


avoided the spider also avoided the contaminated pen.) Table 2 shows the

statistics for this analysis. Consistent with the earlier analyses, peak disgust

significantly predicted avoidance, but anxiety did not. Disgust sensitivity and

anxiety sensitivity did not prove to be significant predictors (w2ð2;n¼100Þ ¼ 2:69,

p > :25).

3. Discussion

Previous research has suggested that disgust is part of the emotional response,

at least for some people, in some types of specific phobia. This study showed

results consistent with this perspective, as high fear participants experienced both

more intense anxiety and more intense disgust than low fear participants in a

behavioral test involving a large spider. Although some low fear participants

(20%) avoided contact with a harmless pen that had been in contact with a spider,

twice as many high fear participants (40%) avoided full contact with the pen. That

we observed group differences on avoidance of the spider was unsurprising. As

expected, high fear participants experienced more anxiety and disgust than low

fear participants. More noteworthy was the result that participants selected for

their self-report of fear of spiders showed a sense of contamination related to the

spider by avoiding eating a cracker that had come in contact with something that

had been in contact with the spider.

A more important question for this study was whether disgust plays a

functional role in phobic avoidance. Avoidance is problematic in phobias for

both practical and theoretical reasons. Individuals who seek treatment for phobias

often choose to do so when avoidance has reached a point of interfering with

important aspects of their lives. On the theoretical side, avoidance is believed to

play a pivotal role in the shift from a fear to a phobia. As both disgust and fear

motivate behavioral withdrawal, the question here is whether disgust, rather than

or in addition to fear, motivates some of the avoidance that is so problematic in

phobias.

Because avoidance was severely skewed, the analyses used logistic regression

to predict completion of the task versus avoidance of any element. Quite

surprisingly, self-reported ‘‘nervous’’ feelings (i.e., anxiety) did not predict

avoidance of the spider or of the contaminated pen when included in a model

with self-reported feelings of being ‘‘grossed out’’ (i.e., disgust). Although the

odds ratios were not large, peak disgust was a significant predictor of avoidance of

both the spider and the pen. This finding is consistent with the report from de Jong

and Muris (2002), who found that spiders’ disgust-evoking status was the best

predictor of spider phobia, whereas the subjective probability of spiders doing

physical harm was a negligible contributor.

Not everyone who avoided the spider also avoided the pen. About half of the

participants (regardless of fear group) who failed to complete the BAT with the

spider also refused completion of the Contaminated Pen BAT. Among those who


completed the spider test without avoidance, only 8 and 19% avoided the

contaminated pen in the low and high fear groups, respectively. Recall that only

three participants avoided a similar pen that had not been in contact with the

spider. Participants in both groups were more afraid of the spider than of the

contaminated pen (although this effect was much more pronounced among

members of the high fear group), but the low fear participants found the spider

and the contaminated pen to be equally disgusting. High fear participants

indicated significantly greater disgust toward the spider than toward the pen.

One way of interpreting these results is that low fear participants did not

experience disgust as a major element of their response to the spider. Although

they reported more fear of the spider than of the contaminated pen, this was not

true for disgust. High fear participants, on the other hand, were more disgusted

and more afraid of the spider than of the pen. Anxiety and disgust were fairly

strongly correlated in both fear groups. For example, during the spider task,

r ¼ :59 and r ¼ :68 for the high and low fear participants. These correlations

could mean that participants were confusing the two emotions, using the labels

less precisely than we intended. That the fear groups diverged in their patterns of

self-reported disgust for the two behavioral tests suggests this explanation is not

tenable.

Another possibility is that the high fear group was more avoidant of the

contaminated pen not due to a specific feeling of disgust or sense of contamination

per se, but from generalization of their spider fear to anything associated with the

spider. Generalization, as it appears in specific phobia, usually occurs for stimuli

that have some physical properties in common with the feared stimulus, such as

leggy creatures or photographs of spiders. To argue that the high fear participants

avoided the contaminated pen as a generalized spider stimulus (and then also

reported more disgust) would seem to stretch the notion of stimulus generalization

as well as, perhaps, the notion of fear.

Thorpe and Salkovskis (1998) suggested that high fear in response to a phobic

stimulus creates arousal that amplifies other negative emotions. This idea is

consistent with the pattern we observed in the high fear group, but it is not

consistent with the emotions reported by the low fear group. Although members

of this group did report some anxiety while approaching the spider (under-

standable, given its size), they did not experience a parallel amplification of

disgust. Thorpe and Salkovskis (1998) explanation also appears unable to account

for elevated general disgust sensitivity among those with spider phobia. For

example, Sawchuk et al. (2002) exposed participants to general disgust elicitors

unrelated to phobic concerns, including a video depicting solid waste, pictures of

rotting foods, and pictures of disgusting bodily products. The spider phobic group

responded with greater disgust and aversion than nonphobic controls.

If at least a subset of phobics experiences disgust as a prominent, or perhaps

dominant, part of their phobic response, then it is important to understand what

happens to disgust during treatment. de Jong et al. (1997) examined this question

in a sample of children and reported that disgust toward the phobic object declined


with exposure therapy. Although de Jong et al. (1997) found that general disgust

sensitivity did not decline with treatment, it does not appear to interfere with

exposure therapy (Merckelbach et al., 1993). Other laboratories have not yet

replicated these studies, and no one has yet examined whether phobic individuals

(or perhaps those with contamination-themed obsessive–compulsive disorder)

can be characterized as having a dominant emotional response of disgust, fear, or

some mixture of the two.

If the results from these studies are robust, then distinguishing between disgust

and fear may not be terribly relevant for treatment. But is disgust or a sense of

contamination so readily diminished? Perhaps disgust is a more heterogeneous

construct than the single word conveys. Contempt, a complicated emotion, has

been described as social disgust (Miller, 1997). The type of disgust that is

accompanied by nausea (e.g., response to smelling spoiled milk) seems different

from the type of disgust that might be characterized as an aversion (e.g., response

to slugs). These various types of disgust may share the same facial expression;

they are all certainly negative emotions and undoubtedly motivate a desire to

withdraw or avoid. Whether they are equally diminished with exposure remains to

be seen. Disgust associated with unfamiliarity might be more easily dispelled, but

that which has cultural taboos (such as those associated with sexual practices,

food, and bodily products) may be less easily altered.

Acknowledgments

This research was supported by a grant from the Social Sciences and

Humanities Research Council of Canada to Sheila Woody. We thank Bethany

Teachman and Nicole Dorfan for their helpful comments on the design and data

analysis.

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Disgust as a motivator of avoidance of spiders