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Gender Differences When Touching Something Gross: Unpleasant? No. Disgusting? Yes! Alexander J. Skolnick
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Saint Joseph's University Published online: 05 Apr 2013.
To cite this article: Alexander J. Skolnick (2013) Gender Differences When Touching Something Gross: Unpleasant? No. Disgusting? Yes!, The Journal of General Psychology, 140:2, 144-157, DOI: 10.1080/00221309.2013.781989 To link to this article: http://dx.doi.org/10.1080/00221309.2013.781989
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The Journal of General Psychology, 2013, 140(2), 144–157 C 2013 Taylor & Francis Group, LLC Copyright
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Gender Differences When Touching Something Gross: Unpleasant? No. Disgusting? Yes! ALEXANDER J. SKOLNICK Saint Joseph’s University
ABSTRACT. While many studies find women self-report higher disgust sensitivity than men, few studies have examined gender differences with behavioral tasks in senses other than vision. On a haptic task, we tested the hypothesis that women would report greater disgust but not greater unpleasantness than men. Forty-four undergraduates (29 women) touched 8 out-of-sight stimuli with sensory (unpleasantness) and emotional (disgust) responses recorded. The stimuli consisted of 2 neutral, 2 pleasant, and 4 unpleasant (3 disgust-evoking) objects. No gender differences were found for reporting stimuli unpleasantness. In contrast, women rated their disgust significantly higher than men when touching the high disgust-evoking objects. Unpleasantness of the stimuli correlated with disgust to the objects, but disgust sensitivity (Disgust Scale–Revised) was not a strong predictor of disgust responses. Besides differentiating unpleasantness from disgust, this was also the first study to show gender differences in a disgust-evoking haptic task. Keywords: disgust, gender differences, haptic, touch
IT IS EASY TO THINK OF THE QUALITIES OF EACH OF THE FIVE MAJOR SENSES that can evoke disgust: odors associated with decay and putrefaction, tastes associated with bitterness, sounds of someone vomiting, and the touch of something slimy (Miller, 1997). However, most research where disgust is evoked in participants use either visual images, such as filthy toilets and bloody bodies, or written scenarios as the standard means of emotion stimulation. Potentially harmful and pathogenic qualities are a common theme across these stimuli, and disgust, as a visceral emotion linked with feelings of revulsion and withdrawal, is Much appreciation goes to the assistants that ably supported this research: Caitlin Kolman-Mandle, John Accardi, Katherine Bascom, J. Michael Hanagan, Megan Healy, Charles Marchione, Kelly McGeehan, Michael Pearl, Amy Phillips, Brian Tyson, and David Wilson. Address correspondence to Alexander J. Skolnick, Department of Psychology, Saint Joseph’s University, 5600 City Avenue, Philadelphia, PA 19131, USA; [email protected] (e-mail). 144
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thought to function to keep humans safe and away from such stimuli (Curtis, de Barra, & Aunger, 2011; Rozin, Haidt, & McCauley, 2008). Although disgust is hypothesized to functionally keep all people safe from potentially contaminating stimuli, many studies find that women show higher disgust than men. Women have higher disgust on self-report measures (Druschel & Sherman, 1999; Haidt, McCauley, & Rozin, 1994; Quigley, Sherman, & Sherman, 1997) as well as higher disgust levels with stimuli from visual domains (e.g., pictures: Simpson, Carter, Anthony, & Overton, 2006; Schienle, Sch¨afer, Stark, Walter & Vaitl, 2005; Films: Rohrmann, Hopp, & Quirin, 2009). As for other sensory domains, no gender differences in disgust have been assessed with auditory stimuli, but a study on taste found women showed higher disgust than men to salt while men and women were equal in elevated disgust to a bitter taste (Robin, Rousmans, Dittmar, & Vernet-Maury, 2003). No study has (yet) found that men and women report different disgust levels in response to disgust-evoking olfactory stimuli (e.g., Koch et al., 2007; Seubert, Rea, Loughead, & Habel, 2009). A few studies have used tactile stimuli to examine disgust (e.g., Oum, Lieberman, & Alyward, 2011; Rozin, Haidt, McCauley, Dunlop, & Ashmore, 1999; Woody & Tolin, 2002), but evidence for gender differences in disgust in this domain is meager. The current study addressed whether gender differences would be evident in a haptic task where out-of-sight disgust-evoking objects would be touched and evaluated. One suggestion for why disgust may be higher in women than men is that women, due to issues surrounding childrearing, need to be easily disgusted to keep their offspring safe (Curtis et al., 2011; Fessler, Pillsworth, & Flamson, 2004). If child protection was an important selective factor we might expect women to be higher in disgust across sensory stimuli that give clues to potential danger to offspring, such as gustatory (e.g., tastes of toxic food items), olfactory (e.g., odor of rotting food sources), and haptic cues (e.g., sliminess indicating potential food items have decayed). So far there is not strong support for gender differences in disgust in response to stimuli from these three sensory domains. An alternative theory following Social Role Theory (Eagly, Wood, & Diekman, 2000) makes a similar prediction about higher disgust in women but argues that the gender difference in disgust may be due to the ways that men and women appear emotional in concordance with their gender roles. In American society, men are expected to fulfill agentic roles that include being goal-oriented, assertive, and courageous, whereas expectations for women, are based on more communal roles that include being nurturing, showing empathy and sympathy, and seeking social connections (Brody, 1999; Rudman & Glick, 2008). Thus, men may appear lower in disgust to seem emotionally tough by aligning with Western masculine roles that promote boldness and control of one’s emotions (Brody, 1999; Shields, 2002; Skolnick, Bascom, & Wilson, 2013). In a recent study, men higher in masculinity were less likely to be willing to display their disgust (Skolnick et al., 2013). Women may appear high in disgust to match feminine expectations of
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more powerless emotions (Fischer & Manstead, 2000), such as fear and disgust. Further research on disgust and gender is needed to begin to understand the sensory limits that delineate men and women’s disgust responses so that alternative explanations can be improved. Disgust induces withdrawal tendencies away from the offending stimulus and feelings of revulsion. Therefore, the thought of touching something with disgust-evoking properties may seem especially disgusting since contact requires proximity and approach. Properties of stimuli that tend to be considered disgusting include wetness, softness, sliminess, stickiness, gooeyness, oiliness, clamminess, etc. (Miller, 1997). These qualities have decay and putrefaction in common, in that the breakdown of cellular matter with decay often produces combinations of moisture, softness, and sliminess. Oum et al. (2011) further suggest that these qualities in organic matter may be indicative of pathogen presence. Disgust may also occur when the touch of something goes against expectations (e.g., expecting watery consistency and finding higher viscosity) or when the feel of a nondisgusting object matches something imagined as disgusting (e.g., bowl of peeled grapes feeling like eyeballs, or how we imagine eyeballs to feel). The use of tactile stimuli to examine disgust has advantages over other types of stimuli. When images evoke disgust, it is the content and meaning of the images (e.g., a dirty toilet) that causes the emotional change, not a specific sensory quality of the light hitting the retina. Likewise, most evidence suggests that people must learn that certain odors are foul and disgust-evoking (Soussignan, Schaal, Marlier, & Jiang, 1997; Stevenson & Repacholi, 2003), as there is little inherent in an odor that specifically evokes disgust. However, the sensory qualities of physical stimuli that are touched may directly contribute to their disgust-evoking properties, especially if the stimuli are not in view. Touching an out-of-sight stimulus will induce one’s imagination in order to make an identification, and any associations that the person has with what is imagined likely influences one’s emotional response. For example, reaching into the refrigerator and touching something slimy and wet may induce thoughts of rotting foods because one knows that foods eventually rot, and sliminess is associated with decay (Miller, 1997). Although the thought of possibly rotting food is disgust-evoking regardless of involving touch, the sensory quality of sliminess directly contributes to this emotional response. It is as yet unknown whether sliminess would be disgusting if one had no knowledge of the kinds of things that are slimy. Thus, we feel that the sensory qualities during tactile contact play a role in the nature of the unpleasant- and disgust-evoking properties. The first study to investigate the tactile qualities that evoke disgust (Oum et al., 2011) had participants touch out-of-sight objects (rope, dough) that were wet or dry and varied in temperature. Five measures were used to indicate their disgust and aversion to the items, including how disgusted they were to touch the item and how disgusted from the thought of putting the object into the mouth. They found wetness and consistency increased disgust responses but not temperature. The only gender difference found was women rated putting the objects
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into the mouth as slightly more disgusting than men. A few other studies have used tactile stimuli to evoke a disgust response. Rozin and colleagues (1999), for example, used a variety of potentially disgusting tactile stimuli; Woody and Tolin (2002) had people put their hand in a bowl of earthworms; and Stevenson, Case, and Oaten (2011) used lumpy soup. But these studies either did not evaluate gender differences or did not report gender differences specific to the tactile tasks. Recognizing the dearth of studies addressing possible gender differences in touch and emotion prompted us to develop a haptic task that allowed the distinction between sensory and affective contributions to gender differences in disgust. We accomplished this by also asking about the sensory qualities of the stimuli, including the pleasantness of the stimuli, and about how participants felt touching the stimuli. With this procedure, we can begin to understand what factors contribute to any possible gender differences in touch-evoking disgust. Given the adaptive argument that women should be higher in disgust than men to be sensitive to contamination cues in the environment (Fessler et al., 2004) and the argument from social role theory that emotions such as disgust and fear are expected to be more prevalent with communal/feminine gender roles than agentic/masculine gender roles, we hypothesized that women would produce stronger disgust ratings in response to touching disgust-evoking stimuli than men. Relatedly, we predicted that there should be no inherent sensory differences in men and women and therefore, they should not differ in assessment of the sensory qualities of the stimuli. Given individual differences in disgust (Haidt et al. 1994; Rozin et al., 1999), we also predicted that one’s disgust sensitivity would modulate the sensorydisgust relationship such that people more easily disgusted (higher scores on a disgust scale) would rate the disgust-evoking stimuli as higher in disgust. Men and women participated by reaching their dominant hand into a box to touch unseen disgust-evoking as well as nondisgust-evoking objects. We used honey to evoke stickiness and gooeyness; worms to evoke squishiness, sliminess, and a wriggling sensation; and oily noodles to evoke an oily slick sensation. Method Participants We tested 44 undergraduates (29 women), all college-aged, and 91% righthanded. The study was approved by the Saint Joseph’s University’s Institutional Review Board. Materials Handedness was established with the Edinburgh Handedness Inventory (EHI; Oldfield, 1971). Disgust sensitivity was assessed with the Disgust Scale-Revised
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(DS-R; Haidt et al., 1994; updated by Olatunji et al., 2007), which was scored with a 2-point (true/false) scale in response to whether the participant is bothered by each of the first 13 statements (e.g., If I see someone vomit, it makes me sick to my stomach). The next 12 items (e.g., You see maggots on a piece of meat in an outdoor garbage pail) were rated for how disgusting each statement was on a 3-point scale with 0 (“Not”), 1 (“Slightly”), and 2 (“Very”). An overall mean was calculated and Cronbach’s α = .81. Sensory aspects of the objects were measured on nine bipolar scales (DullSharp, Wet-Dry, Smooth-Rough, Mushy-Solid, Soft-Hard, Slippery-Coarse, OilyNot Oily, Sticky-Not Sticky, Pleasant-Unpleasant) in response to the question, “How does the object feel?” These were on a 9-point scale (0-8) with the lefthand adjective at 0 (e.g., Dull), “Neither” at 4, and 8 by the right-hand adjective (e.g., Sharp). It was pointed out that if they believed neither adjective applied they could select 4 as “Neither.” The Pleasant-Unpleasant scale was the targeted adjective pair that was of interest as it indicated the overall valence of the tactile feeling. Below, on the same sheet, participants were asked to rate their emotional response to the touch: “How do YOU feel with your hand in contact with the object?” Nine emotion terms were rated on a 9-point scale (0-8), with “Low” at 0 and “High” at 8: Happy, Surprised, Embarrassed, Angry, Grossed out, Silly, Proud, Nervous, Excited. We chose the term, “Grossed out” instead of “Disgusted” based on research by Nabi (2002) who showed the lay understanding for “disgust” is commonly anger and not revulsion-related disgust. It was pointed out that if they did not feel the emotion, 0 was appropriate, not 4. They were then asked to name the object if they could.
Stimuli and Apparatus The stimuli were all presented in a large square box that participants reached around the side with their dominant arm. They were blind to the stimuli throughout the session. Stimuli were in mounted bowls to avoid being accidentally tipped over. The disgust-evoking and unpleasant objects were honey with Grape Nuts cereal in it (represented gooey, sticky), oily cooked smooth rigatoni noodles (slippery, oily), and live earthworms (squishy, wriggling). The nondisgusting and unpleasant object (control) was a 7 cm diameter disk with screws glued to it in every direction (sharp). The neutral objects were three small raw wooden blocks (3.8 cm each dimension) and room-temperature water. Two positive objects were a round smooth wooden ball (5 cm diameter) and a bowlful of soft cotton pom-poms (3 cm diameter). There was variation in sample size across the measures. Fewer sessions were run that included earthworms (n = 37, 24 women) when the worms died and we were delayed in replacing them. All sessions included Honey and Noodles (n = 44, 29 women).
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Procedure After reading and signing the consent form, electrodes were situated for physiological recordings (not reported here). Participants gave a verbal response for their handedness to set up the box. On each of 8 trials, participants reached their dominant arm through an opening on the side of the box and put their hand in the bowl to feel the object. With their hand in contact with the object they used their non-dominant hand to record the sensory properties of the objects and their emotions, by using a thick-nibbed marker to make marks in the appropriate boxes. After each trial that involved water, honey, oily noodles, or worms, participants were given paper towels to clean their hand. We anticipated order effects, since encountering the disgust items might alter their expectations about future items. We created three pseudorandom orders (controlling what came first) and reversed them producing six different orders and assigned them randomly. To avoid alterations in reported disgust due to a mixed gender audience, male experimenters tested all the male participants, and female experimenters tested all female participants. After the last object, participants completed the EHI and DS-R.
Results Possible order effects were tested with 2 (gender) x 6 (orders) betweensubject MANOVAs on unpleasantness and disgust ratings. No significant effects were found at the .05 level so order will not be considered further. Both sets of unpleasant and disgust ratings for the three disgust-evoking stimuli (Worms, Honey, Noodles) were significantly intercorrelated (Table 1), and although the
TABLE 1. Correlation Coefficients for DS-R Scales and Disgust and Unpleasant Ratings 1 1. Worm Disgust 2. Honey Disgust 3. Noodle Disgust 4. Worm Unpleasant 5. Honey Unpleasant 6. Noodle Unpleasant DS-R total
.29
2
3
4
5
6
.72∗∗∗
.52∗∗∗ .38∗
.36∗ .44∗∗ —
.62∗∗∗ .75∗∗∗ .30∗ .55∗∗∗
.23 .25 .69∗∗∗ .34∗ .38∗
—
—
.20
.35∗
—
Note. Only r-values ≥ .20 listed. For Disgust and Unpleasant ratings df = 35 (Worms), df = 42 (Honey), df = 39 (Noodles); for DS-R measures df = 32 (Worms) and df = 39 (others). ∗ p < .05. ∗∗ p < .01. ∗∗∗ p < .001.
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Mean Unpleasant Ratings (0 - 8)
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8
Men
7
Women
6 5 4 3 2 1 0 Worms
Honey
Noodles
Screws
Water
Blocks
Round Pompoms
FIGURE 1. Mean unpleasantness ratings for all items. Ratings were from 0 (Pleasant) to 4 (Neither) to 8 (Unpleasant). Noodles = Oily Noodles. Round = Round Wood. Error bars based on standard error of the mean.
r-squared values were small to moderate (from .12 to .52) this finding suggests some consistency in response to the disgust-evoking items within individuals. Mixed ANOVAs were used to test the main hypotheses. When Mauchly’s test of sphericity was significant, Greenhouse-Geisser df corrections were used to adjust the p-values. An 8 (stimuli) × 2 (gender) mixed ANOVA found that the stimuli differed in their unpleasant ratings, F(7, 245) = 26.50, p < .001, partial η2 = .431, with Worms, Honey and Noodles, along with Screws all rated more unpleasant than the four neutral and positive items, all p < .001, except for the Noodles which were only slightly more unpleasant than the others p < .05 (Figure 1). No main effect for gender, F(1, 35) < 1, or interaction, F(1, 245) < 1, was seen supporting our predictions that the sensory aspects of the stimuli would not differ by gender. A similar mixed ANOVA used to assess disgust ratings showed a main effect for stimuli, F(7, 245) = 41.57, p < .001, partial η2 = .543 (Figure 2). Bonferroni comparisons revealed that Worms were not different from Honey but were rated higher in disgust than all other stimuli (all p < .001), including Noodles (p < .026); Honey was not different from Noodles, but was rated as significantly more disgusting than all other stimuli (all p < .001); and Noodles was rated more disgusting than Screws (p = .001) and the neutral and positive stimuli, all p < .001. There was no overall effect of gender, F(1, 35) = 2.51, p = .12, partial η2 = .067, but the
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*
Mean Disgust Rating (0 - 8)
Men
*
5
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Women
4
3
2
1
0 Worms
Honey
Noodles
Screws
Water
Blocks
Round
Pompoms
FIGURE 2. Mean disgust (“Grossed out”) ratings for all items. Ratings were from 0 (Low) to 8 (High). Noodles = Oily Noodles. Round = Round Wood. Error bars based on standard error of the mean. ∗ p < .05 for differences between men and women.
interaction between gender and stimuli was significant, F(2.99, 104.69) = 2.70, p = .05, partial η2 = .072. Independent t-tests with corrected degrees of freedom were used for to adjust the p-values when Levene’s test for equality of variances was significant. These tests showed that women’s rated disgust was higher than men’s rated disgust only for Worms, t(34.99) = 2.66, p = .012, d = .77, and Honey, t(42) = 2.03, p = .049, d = .64 (Figure 2). As predicted, differences between men and women were found when touching unseen disgust-evoking stimuli (Worms, Honey). No gender difference was found for the Noodles, which was the least disgust-evoking of the three stimuli. Participants were asked to name the objects after they recorded their responses, and these labels may have affected their disgust responses. While 48.6% of the participants thought they were touching worms, 13.5% of participants thought the worms were “gummy worms” or “candy worms” when trying to identify the stimuli. Since these are positively valenced categories, we reanalyzed the t-test for Worms after dropping those participants, which revealed a larger gender difference, t(25.09) = 3.58, p = .001, d = 1.27. Dropping these participants had no effect on mean unpleasant rating for Worms. Overall, the disgust-evoking objects showed different trends in recognition accuracy. Noodles were the most identifiable object, and no gender differences in the percent recognized were evident (73% by men,
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77% by women). Gender differences were seen for the other two stimuli, with a trend for men to better recognize they were touching worms (69% versus 37.5%, p = .09, Fisher Exact Test), and women were significantly better at identifying honey (38% versus 6.7%, p = .035, Fisher Exact Test). It was clear that the unpleasantness of the feel of the stimuli was related to the disgust one felt from the stimuli, as unpleasantness and disgust were significantly correlated for each disgust-evoking stimulus, Worms: r(35) = .36, p = .031, Honey: r(42) = .75, p < .001, Noodles: r(42) = .69, p < .001. Interestingly, running another set of correlations between disgust ratings of the stimuli and any of the other sensory ratings (Wet/Dry, Mushy/Solid, etc.) besides unpleasantness, found no significant correlations for the three disgust stimuli. Overall, no sensory aspect during contact with the stimuli was related to disgust feelings except for how unpleasant the stimuli felt. Women reported significantly higher disgust sensitivity measured with the DS-R, Mmen = 1.76, SD = 0.19, Mwomen = 1.96, SD = 0.24, t(39) = 2.73, p = .009, d = .90. However, contrary to our hypothesis that people higher in disgust sensitivity would rate their disgust higher in response to touching the disgust-evoking stimuli, we did not find a strong relationship in this regard. Correlations (Table 1) between mean DS-R scores and its subscales with rated disgust for each item indicated only a moderate relationship between disgust sensitivity and Honey disgust. If the DS-R was entered as the sole predictor of the disgust ratings, it accounted for 8% of the variance in Worm disgust (β = .289, t = 1.71, p = .09), 12% of the variance in Honey disgust (β = .346, t = 2.29, p = .027), and zero variance for Noodles disgust.
Discussion This study examined gender differences in disgust using a haptic task where we could assess both sensory qualities of the disgust-evoking stimuli and the resulting affective responses. We found predicted gender differences in disgust responses to the stimuli, but no gender differences in ratings of the sensory qualities of the stimuli. Women rated their disgust higher than men for the two most disgustevoking stimuli (Worms & Honey) but were not different from men when asked to rate how unpleasant the items felt. We successfully showed that the designated unpleasant stimuli (Worms, Honey, Noodles, Screws) were more unpleasant than the designated neutral (Blocks, Water) or positive stimuli (Round, Pompoms), and that the designated disgust-evoking objects produced higher-rated disgust than the other five stimuli. The sensations we tried to produce, such as stickiness, sliminess, oiliness, appeared to have successfully evoked disgust-related feelings in the participants. Our results also suggest that variation in participants’ ratings of oiliness, stickiness, wetness, etc. were not separately influential determinants of disgust levels. Rather, a Gestalt of the suite of characteristics may be necessary to
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generate imagery of the contacted stimulus that could be the greater determining factor for generating disgust. Are there gender differences in haptic abilities that may contribute to or explain our results? The evidence for gender differences in haptic abilities is mixed, with most studies finding no strong gender differences in manual touch of objects (e.g., Fagot, Lacreuse, & Vauclair, 1993; Robert & Chevrier, 2003). Some studies do find men to be more accurate in haptic tasks (e.g., Cohen & Levy, 1986; Zuidhoek, Kappers, & Postma, 2007). It is unclear if men do have an advantage, how that would explain their affective responses. We found that men were better at identifying they were touching worms than women, but not as good at identifying honey. The directionality of these identification differences did not directly translate into differences in disgust, so it is unlikely that gender differences in haptic skills underlies the gender differences seen in disgust responsiveness. Why should touching sticky and wormy things produce different levels of disgust in women and men? Our results suggest that the unpleasant nature of the stimuli produced similar ratings in men and women, so separate affective processes are likely responsible for the observed differences. We cannot determine whether biologically based differences in thresholds to respond with disgust differed in men and women. It could be that men and women both rate a 6 for unpleasantness to touching worms, but a 6 in women generates a disgust response but it takes a higher value, such as an 8 for men. Alternatively, the differences in disgust between men and women may be truly minimal, but that gender role expectations drive women to be more expressive about disgust and men to be less expressive about disgust (Skolnick et al., 2013). We have also argued that gross-out disgust should be considered a powerless emotion that could make men appear weak and less manly. Thus, men may be motivated to show themselves to be low in disgust to meet with masculine expectations (Skolnick et al., 2013). Our results are consistent with this view, as the men rarely gave high ratings to the disgust objects. In the current study, we tried to avoid this trend by always having male experimenters conducting the sessions with male participants. However, we cannot completely rule out an audience effect because men may be motivated to appear masculine by suppressing their disgust reactions in front of other men as well as women. Future paradigms designed to remove audience effects from haptic research would be helpful in determining whether men possibly suppress their disgust in front of others. That women were more disgusted than men for the two most disgust-evoking stimuli lends support to the alternative theory that women should be higher in disgust to protect their reproductive interests (Curtis et al., 2011; Fessler et al., 2004). Being more disgust sensitive to the touch of certain objects would fit with the protective role a mother adopts during childrearing. Oum and colleagues (2011) suggested the touch qualities that normally induce disgust (e.g., wetness, sliminess) might be cues to pathogens. Thus, this heightened avoidance of pathogens could be an underlying mechanism producing greater disgust in women from touching
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tactile indicators of decay and disease. Future studies should examine specific tactile cues that may be more or less likely to be indicators of pathogen presence to examine whether women showed heightened disgust to the former stimuli. Oum and colleagues has made the first attempt investigating wetness and temperature, but no gender differences in disgust based on these cues were found apart from women being more disgusted than men at the thought of putting the disgustevoking items in their mouth. It may be noted that the current participants were typical young college students and not parents. It is possible that increased tactile exposure to disgustevoking body products that come with raising an infant (e.g., feces, spit-up, mucus) may alter one’s levels of disgust when touching stimuli. Thus, it may be important to examine tactile disgust in a population of new parents to establish whether such experiential effects influence the size and direction of gender differences in disgust. We predicted that people higher in trait disgust sensitivity, as measured by the DS-R, would show higher disgust to the three disgust-evoking stimuli. However, unlike Oum and colleagues (2011), we did not find that disgust sensitivity was very predictive of the disgust ratings to the touched stimuli (Table 1). The DS-R was significantly related to Honey disgust but only showed a marginally significant trend with Worms (likely due to limited sample size given an r-value of .29) or Noodles. The Noodles were only somewhat disgusting for most people, so it may be appropriate that DS-R scores were not predictive of Noodles disgust ratings. Our data were aligned with Woody and Tolin (2002) who found that with behavioral tasks that evoke disgust, the Disgust Scale was not as strong a predictor of avoidance of disgusting tasks as state disgust (although the one stimulus that DS was predictive of was touching worms). The disgust-evoking qualities of the stimuli may have been intense enough that whether one was low or high in disgust sensitivity, the stimuli generated disgust regardless. One last limitation of the use of the DS-R was that participants filled it out after touching the objects, and its score may have been influenced by the touch session. We chose to present the survey afterward to avoid the survey alerting participants about the target emotion of interest because we did not want their disgust responses to be biased, as is possible if the DS-R scale is given first. We did find the typical large gender difference on the DS-R (Druschel & Sherman, 1999; Haidt et al., 1994; Quigley et al., 1997), suggesting no obvious biases occurred due to the order of presentation. An interesting aspect of the phenomenon of touch-induced disgust is the fact that the touch forces contact with something that a person finds aversive and would want to withdraw. Therefore, a possible limitation of our study was the use of the box to hide the stimuli from view. By making participants touch unseen objects, we were forcing them to imagine what they were touching and think about the identity of the object. Some people had accurate ideas about the objects and some had inaccurate ideas or no ideas. Thus, there may have been variation in the sources
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of information that cued their disgust feelings. We did find that people thinking they were touching candy-style worms gave much lower ratings of disgust than people thinking they were touching actual worms. This variability in imagery of what is being touched could possibly alter the relationship between a person’s disgust sensitivity and disgust ratings based on tactile contact. Individual differences in imagery abilities have also been seen to influence emotion-evoked arousal, with better imagers showing greater arousal from viewing affective pictures (Lang, Greenwald, Bradley, & Hamm, 1993). The role of additional sensory cues besides haptic cues may also aid in understanding how gender differences in disgust manifest when touching a stimulus. For example, visual cues prior to touch could either enhance the affective feelings with contact (e.g., if there are visual cues making the stimulus appear disgust-evoking) or lessen the affective feelings (e.g., if the appearance of the stimulus does not alone evoke disgust). Further research on haptic cues to disgust may profit from comparing haptic-only cue conditions (that likely instigate imagery) to haptic plus visual cue conditions (that do not require imagery). Rozin and colleagues (1999) and Woody and Tolin (2002) used visible stimuli for tactile-induced disgust but did not have tactile-only conditions for comparison. In conclusion, when offered an unseen sticky, slimy, or oily stimulus, men and women responded similarly when asked about how unpleasant or pleasant something feels, but they responded differently when asked how disgustedly “grossed out” they felt. Women scored higher on the Disgust Scale than men and also rated two of the three disgust items higher in disgust than men. For the third item, oily noodles, women’s levels of disgust were lower than for Worms and Honey and were equal to men’s levels, which were more uniformly low. An unpleasant item, a disk of somewhat sharp screws, produced little disgust for either gender, thus showing that disgust was not the result of an item being merely unpleasant to the touch. We also found that sensory qualities of the stimuli, other than how unpleasant it felt, did not vary with how disgusting one felt touching the item. We did not find an expected strong relationship between a person’s disgust sensitivity and their disgust ratings in the task. Further research is required to elaborate on the relationship between a person’s trait levels of disgust and their responses to disgust-evoking stimuli. Understanding the nature of gender differences in disgust uncovered here adds to our understanding of the ways men and women process emotional stimuli differentially. AUTHOR NOTE Alexander J. Skolnick, is in the Department of Psychology at Saint Joseph’s University in Philadelphia, PA. REFERENCES Brody, L. R. (1999). Gender, emotion, and the family. Cambridge, MA: Harvard University Press.
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Cohen, H., & Levy, J. J. (1986). Sex differences in categorization of tactile stimuli. Perceptual and Motor Skills, 63, 83–86. Curtis, V., de Barra, M., & Aunger, R. (2011). Disgust as an adaptive system for disease avoidance behaviour. Philosophical Transactions of the Royal Society B, 366, 389–401. doi:10.1098/rstb.20 10.0117 Druschel, B. A., & Sherman, M. F. (1999). Disgust sensitivity as a function of the Big Five and gender. Personality and Individual Differences, 26, 739–748. Eagly, A. H., Wood, W., & Diekman, A. B. (2000). Social roles theory of sex differences and similarities: A current appraisal. In T. Eckes & H. M. Trautner (Eds.), The developmental social psychology of gender (pp. 123–174). Mahwah, NJ: Lawrence Erlbaum. Fagot, J., Lacreuse, A., & Vauclair, J. (1993). Haptic discrimination of nonsense shapes: Hand exploratory strategies but not accuracy reveal laterality effects. Brain & Cognition, 21, 212–225. Fessler, D. M. T., Pillsworth, E. G., & Flamson, T. J. (2004). Angry men and disgusted women: An evolutionary approach to the influence of emotions on risk taking. Organizational Behavior and Human Decision Processes, 95, 107–123. doi:10.1016/j.obhdp.2004.06.006 Fischer, A. H., & Manstead, A. S. R. (2000). The relation between gender and emotion in different cultures. In A. H. Fischer (Ed.), Gender and emotion, social psychological perspectives (pp. 71–94). Cambridge, UK: Cambridge University Press. Haidt, J., McCauley, C., & Rozin, P. (1994). Individual differences in sensitivity to disgust: A scale sampling seven domains of disgust elicitors. Personality and Individual Differences, 16, 701–713. Koch, K., Pauly, K., Kellermann, T., Seiferth, N. Y., Reske, M., Backes, V., . . . Habel, U. (2007). Gender differences in the cognitive control of emotion: An fMRI study. Neuropsychologia, 45, 2744–2754. doi:10.1016/j.neuropsychologia.2007. 04.012 Lang, P. J., Greenwald, M. K., Bradley, M. M., & Hamm, A. O. (1993). Looking at pictures: Affective, facial, visceral, and behavioral reactions. Psychophysiology, 30, 261–273. Miller, W. I. (1997). The anatomy of disgust. Cambridge, MA: Harvard University Press. Nabi, R. L. (2002). The theoretical versus lay meaning of disgust: Implications for emotion research. Cognition and Emotion, 16, 695–703. doi:10.1080/02699930143000437 Olatunji, B. O., Williams, N. L., Tolin, D. F., Abramowitz, J. S., Sawchuk, C. N., Lohr, J. M., & Elwood, L. S. (2007). The disgust scale: Item analysis, factor structure, and suggestions for refinement. Psychological Assessment, 19, 281–297. doi:10.1037/10403590.19.3.281 Oldfield, R.C., 1971. The assessment and analysis of handedness: The Edinburgh inventory. Neuropsychologia, 9, 97–113. doi:10.1016/0028-3932(71)90067-4. Oum, R. E., Lieberman, D., & Aylward, A. (2011). A feel for disgust: Tactile cues to pathogen presence. Cognition and Emotion, 25, 717–725. doi:10.1080/ 02699931.2010.496997. Quigley, J. F., Sherman, M. F., & Sherman, N. C. (1997). Personality disorder symptoms, gender, and age as predictors of adolescent disgust sensitivity. Personality and Individual Differences, 11, 550–556. Robert, M., & Chevrier, E. (2003). Does men’s advantage in mental rotation persist when real three-dimensional objects are either felt or seen? Memory & Cognition, 31, 1136–1145. Robin, O., Rousmans, S., Dittmar, A., & Vernet-Maury, E. (2003). Gender influence on emotional responses to primary tastes. Physiology & Behavior, 78, 385–393. doi:10.1016/S0031-9384(02)00981-2
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Rohrmann, S., Hopp, H., & Quirin, M. (2008). Gender differences in psychophysiological responses to disgust. Journal of Psychophysiology, 22, 65–75. doi:10.1027/02698803.22.2.65 Rozin, P., Haidt, J., & McCauley, C. R. (2008). Disgust. In M. Lewis, J. M. Haviland-Jones, & L. Feldman Barrett (Eds.), Handbook of emotions (3rd Ed., pp. 757–776). New York, NY: Guilford. Rozin, P., Haidt, J., McCauley, C. R., Dunlop, L., & Ashmore, M. (1999). Individual differences in disgust sensitivity: Comparisons and evaluations of paper-and-pencil versus behavioral measures. Journal of Research in Personality, 33, 330–351. Rudman, L. A., & Glick, P. (2008). The social psychology of gender: How power and intimacy shape gender relations. New York, NY: Guilford Press. Schienle, A., Sch¨afer, A., Stark, R., Walter, B., & Vaitl, D. (2005). Gender differences in the processing of disgust- and fear-inducing pictures: An fMRI study. NeuroReport, 16, 277–280. Seubert, J., Rea, A. F., Loughead, J., & Habel, U. (2009). Mood induction with olfactory stimuli reveals differential affective responses in males and females. Chemical Senses, 34, 77–84. doi:10.1093/chemse/bjn054. Shields, S. A. (2002). Speaking from the heart: Gender and the social meaning of emotion. Cambridge, UK: Cambridge University Press. Simpson, J., Carter, S., Anthony, S.H., & Overton, P.G. (2006). Is disgust a homogeneous emotion? Motivation and Emotion, 30, 31–41. doi:10.1007/s11031-006-9005-1. Skolnick, A. J., Bascom, K. L., & Wilson, D. T. (2013). Gender role expectations of disgust: Men are low and women are high. Sex Roles. doi: 10.1007/s11199-013-0279y Soussignan, R., Schaal, B., Marlier, L., & Jiang, T. (1997). Facial and autonomic responses to biological and artificial stimuli in human neonates: Re-examining early hedonic discrimination of odors. Physiology and Behavior, 62, 745–758. Stevenson, R. J., Case, T. I., & Oaten, M. J. (2011). Effect of self-reported sexual arousal on responses to sex-related and non-sex-related disgust cues. Archives of Sexual Behavior, 40, 79–85. doi:10.1007/s10508-009-9529-z. Stevenson, R. J., & Repacholi, B. M. (2003). Age-related changes in children’s hedonic response to male body odor. Developmental Psychology, 39, 670–679. doi:10.1037/00121649.39.4.670 Woody, S. R., & Tolin, D. F. (2002). The relationship between disgust sensitivity and avoidant behavior: Studies of clinical and nonclinical samples. Journal of Anxiety Disorders, 16, 543–559. Zuidhoek, S., Kappers, A. M. L., & Postma, A. (2007). Haptic orientation perception: Sex differences and lateralization of functions. Neuropsychologia, 45, 332–341.
Original manuscript received September 7, 2012 Final version accepted February 28, 2013
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Gender Differences When Touching Something Gross: Unpleasant? No. Disgusting? Yes! Alexander J. Skolnick
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Saint Joseph's University Published online: 05 Apr 2013.
To cite this article: Alexander J. Skolnick (2013) Gender Differences When Touching Something Gross: Unpleasant? No. Disgusting? Yes!, The Journal of General Psychology, 140:2, 144-157, DOI: 10.1080/00221309.2013.781989 To link to this article: http://dx.doi.org/10.1080/00221309.2013.781989
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Gender Differences When Touching Something Gross: Unpleasant? No. Disgusting? Yes! ALEXANDER J. SKOLNICK Saint Joseph’s University
ABSTRACT. While many studies find women self-report higher disgust sensitivity than men, few studies have examined gender differences with behavioral tasks in senses other than vision. On a haptic task, we tested the hypothesis that women would report greater disgust but not greater unpleasantness than men. Forty-four undergraduates (29 women) touched 8 out-of-sight stimuli with sensory (unpleasantness) and emotional (disgust) responses recorded. The stimuli consisted of 2 neutral, 2 pleasant, and 4 unpleasant (3 disgust-evoking) objects. No gender differences were found for reporting stimuli unpleasantness. In contrast, women rated their disgust significantly higher than men when touching the high disgust-evoking objects. Unpleasantness of the stimuli correlated with disgust to the objects, but disgust sensitivity (Disgust Scale–Revised) was not a strong predictor of disgust responses. Besides differentiating unpleasantness from disgust, this was also the first study to show gender differences in a disgust-evoking haptic task. Keywords: disgust, gender differences, haptic, touch
IT IS EASY TO THINK OF THE QUALITIES OF EACH OF THE FIVE MAJOR SENSES that can evoke disgust: odors associated with decay and putrefaction, tastes associated with bitterness, sounds of someone vomiting, and the touch of something slimy (Miller, 1997). However, most research where disgust is evoked in participants use either visual images, such as filthy toilets and bloody bodies, or written scenarios as the standard means of emotion stimulation. Potentially harmful and pathogenic qualities are a common theme across these stimuli, and disgust, as a visceral emotion linked with feelings of revulsion and withdrawal, is Much appreciation goes to the assistants that ably supported this research: Caitlin Kolman-Mandle, John Accardi, Katherine Bascom, J. Michael Hanagan, Megan Healy, Charles Marchione, Kelly McGeehan, Michael Pearl, Amy Phillips, Brian Tyson, and David Wilson. Address correspondence to Alexander J. Skolnick, Department of Psychology, Saint Joseph’s University, 5600 City Avenue, Philadelphia, PA 19131, USA; [email protected] (e-mail). 144
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thought to function to keep humans safe and away from such stimuli (Curtis, de Barra, & Aunger, 2011; Rozin, Haidt, & McCauley, 2008). Although disgust is hypothesized to functionally keep all people safe from potentially contaminating stimuli, many studies find that women show higher disgust than men. Women have higher disgust on self-report measures (Druschel & Sherman, 1999; Haidt, McCauley, & Rozin, 1994; Quigley, Sherman, & Sherman, 1997) as well as higher disgust levels with stimuli from visual domains (e.g., pictures: Simpson, Carter, Anthony, & Overton, 2006; Schienle, Sch¨afer, Stark, Walter & Vaitl, 2005; Films: Rohrmann, Hopp, & Quirin, 2009). As for other sensory domains, no gender differences in disgust have been assessed with auditory stimuli, but a study on taste found women showed higher disgust than men to salt while men and women were equal in elevated disgust to a bitter taste (Robin, Rousmans, Dittmar, & Vernet-Maury, 2003). No study has (yet) found that men and women report different disgust levels in response to disgust-evoking olfactory stimuli (e.g., Koch et al., 2007; Seubert, Rea, Loughead, & Habel, 2009). A few studies have used tactile stimuli to examine disgust (e.g., Oum, Lieberman, & Alyward, 2011; Rozin, Haidt, McCauley, Dunlop, & Ashmore, 1999; Woody & Tolin, 2002), but evidence for gender differences in disgust in this domain is meager. The current study addressed whether gender differences would be evident in a haptic task where out-of-sight disgust-evoking objects would be touched and evaluated. One suggestion for why disgust may be higher in women than men is that women, due to issues surrounding childrearing, need to be easily disgusted to keep their offspring safe (Curtis et al., 2011; Fessler, Pillsworth, & Flamson, 2004). If child protection was an important selective factor we might expect women to be higher in disgust across sensory stimuli that give clues to potential danger to offspring, such as gustatory (e.g., tastes of toxic food items), olfactory (e.g., odor of rotting food sources), and haptic cues (e.g., sliminess indicating potential food items have decayed). So far there is not strong support for gender differences in disgust in response to stimuli from these three sensory domains. An alternative theory following Social Role Theory (Eagly, Wood, & Diekman, 2000) makes a similar prediction about higher disgust in women but argues that the gender difference in disgust may be due to the ways that men and women appear emotional in concordance with their gender roles. In American society, men are expected to fulfill agentic roles that include being goal-oriented, assertive, and courageous, whereas expectations for women, are based on more communal roles that include being nurturing, showing empathy and sympathy, and seeking social connections (Brody, 1999; Rudman & Glick, 2008). Thus, men may appear lower in disgust to seem emotionally tough by aligning with Western masculine roles that promote boldness and control of one’s emotions (Brody, 1999; Shields, 2002; Skolnick, Bascom, & Wilson, 2013). In a recent study, men higher in masculinity were less likely to be willing to display their disgust (Skolnick et al., 2013). Women may appear high in disgust to match feminine expectations of
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more powerless emotions (Fischer & Manstead, 2000), such as fear and disgust. Further research on disgust and gender is needed to begin to understand the sensory limits that delineate men and women’s disgust responses so that alternative explanations can be improved. Disgust induces withdrawal tendencies away from the offending stimulus and feelings of revulsion. Therefore, the thought of touching something with disgust-evoking properties may seem especially disgusting since contact requires proximity and approach. Properties of stimuli that tend to be considered disgusting include wetness, softness, sliminess, stickiness, gooeyness, oiliness, clamminess, etc. (Miller, 1997). These qualities have decay and putrefaction in common, in that the breakdown of cellular matter with decay often produces combinations of moisture, softness, and sliminess. Oum et al. (2011) further suggest that these qualities in organic matter may be indicative of pathogen presence. Disgust may also occur when the touch of something goes against expectations (e.g., expecting watery consistency and finding higher viscosity) or when the feel of a nondisgusting object matches something imagined as disgusting (e.g., bowl of peeled grapes feeling like eyeballs, or how we imagine eyeballs to feel). The use of tactile stimuli to examine disgust has advantages over other types of stimuli. When images evoke disgust, it is the content and meaning of the images (e.g., a dirty toilet) that causes the emotional change, not a specific sensory quality of the light hitting the retina. Likewise, most evidence suggests that people must learn that certain odors are foul and disgust-evoking (Soussignan, Schaal, Marlier, & Jiang, 1997; Stevenson & Repacholi, 2003), as there is little inherent in an odor that specifically evokes disgust. However, the sensory qualities of physical stimuli that are touched may directly contribute to their disgust-evoking properties, especially if the stimuli are not in view. Touching an out-of-sight stimulus will induce one’s imagination in order to make an identification, and any associations that the person has with what is imagined likely influences one’s emotional response. For example, reaching into the refrigerator and touching something slimy and wet may induce thoughts of rotting foods because one knows that foods eventually rot, and sliminess is associated with decay (Miller, 1997). Although the thought of possibly rotting food is disgust-evoking regardless of involving touch, the sensory quality of sliminess directly contributes to this emotional response. It is as yet unknown whether sliminess would be disgusting if one had no knowledge of the kinds of things that are slimy. Thus, we feel that the sensory qualities during tactile contact play a role in the nature of the unpleasant- and disgust-evoking properties. The first study to investigate the tactile qualities that evoke disgust (Oum et al., 2011) had participants touch out-of-sight objects (rope, dough) that were wet or dry and varied in temperature. Five measures were used to indicate their disgust and aversion to the items, including how disgusted they were to touch the item and how disgusted from the thought of putting the object into the mouth. They found wetness and consistency increased disgust responses but not temperature. The only gender difference found was women rated putting the objects
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into the mouth as slightly more disgusting than men. A few other studies have used tactile stimuli to evoke a disgust response. Rozin and colleagues (1999), for example, used a variety of potentially disgusting tactile stimuli; Woody and Tolin (2002) had people put their hand in a bowl of earthworms; and Stevenson, Case, and Oaten (2011) used lumpy soup. But these studies either did not evaluate gender differences or did not report gender differences specific to the tactile tasks. Recognizing the dearth of studies addressing possible gender differences in touch and emotion prompted us to develop a haptic task that allowed the distinction between sensory and affective contributions to gender differences in disgust. We accomplished this by also asking about the sensory qualities of the stimuli, including the pleasantness of the stimuli, and about how participants felt touching the stimuli. With this procedure, we can begin to understand what factors contribute to any possible gender differences in touch-evoking disgust. Given the adaptive argument that women should be higher in disgust than men to be sensitive to contamination cues in the environment (Fessler et al., 2004) and the argument from social role theory that emotions such as disgust and fear are expected to be more prevalent with communal/feminine gender roles than agentic/masculine gender roles, we hypothesized that women would produce stronger disgust ratings in response to touching disgust-evoking stimuli than men. Relatedly, we predicted that there should be no inherent sensory differences in men and women and therefore, they should not differ in assessment of the sensory qualities of the stimuli. Given individual differences in disgust (Haidt et al. 1994; Rozin et al., 1999), we also predicted that one’s disgust sensitivity would modulate the sensorydisgust relationship such that people more easily disgusted (higher scores on a disgust scale) would rate the disgust-evoking stimuli as higher in disgust. Men and women participated by reaching their dominant hand into a box to touch unseen disgust-evoking as well as nondisgust-evoking objects. We used honey to evoke stickiness and gooeyness; worms to evoke squishiness, sliminess, and a wriggling sensation; and oily noodles to evoke an oily slick sensation. Method Participants We tested 44 undergraduates (29 women), all college-aged, and 91% righthanded. The study was approved by the Saint Joseph’s University’s Institutional Review Board. Materials Handedness was established with the Edinburgh Handedness Inventory (EHI; Oldfield, 1971). Disgust sensitivity was assessed with the Disgust Scale-Revised
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(DS-R; Haidt et al., 1994; updated by Olatunji et al., 2007), which was scored with a 2-point (true/false) scale in response to whether the participant is bothered by each of the first 13 statements (e.g., If I see someone vomit, it makes me sick to my stomach). The next 12 items (e.g., You see maggots on a piece of meat in an outdoor garbage pail) were rated for how disgusting each statement was on a 3-point scale with 0 (“Not”), 1 (“Slightly”), and 2 (“Very”). An overall mean was calculated and Cronbach’s α = .81. Sensory aspects of the objects were measured on nine bipolar scales (DullSharp, Wet-Dry, Smooth-Rough, Mushy-Solid, Soft-Hard, Slippery-Coarse, OilyNot Oily, Sticky-Not Sticky, Pleasant-Unpleasant) in response to the question, “How does the object feel?” These were on a 9-point scale (0-8) with the lefthand adjective at 0 (e.g., Dull), “Neither” at 4, and 8 by the right-hand adjective (e.g., Sharp). It was pointed out that if they believed neither adjective applied they could select 4 as “Neither.” The Pleasant-Unpleasant scale was the targeted adjective pair that was of interest as it indicated the overall valence of the tactile feeling. Below, on the same sheet, participants were asked to rate their emotional response to the touch: “How do YOU feel with your hand in contact with the object?” Nine emotion terms were rated on a 9-point scale (0-8), with “Low” at 0 and “High” at 8: Happy, Surprised, Embarrassed, Angry, Grossed out, Silly, Proud, Nervous, Excited. We chose the term, “Grossed out” instead of “Disgusted” based on research by Nabi (2002) who showed the lay understanding for “disgust” is commonly anger and not revulsion-related disgust. It was pointed out that if they did not feel the emotion, 0 was appropriate, not 4. They were then asked to name the object if they could.
Stimuli and Apparatus The stimuli were all presented in a large square box that participants reached around the side with their dominant arm. They were blind to the stimuli throughout the session. Stimuli were in mounted bowls to avoid being accidentally tipped over. The disgust-evoking and unpleasant objects were honey with Grape Nuts cereal in it (represented gooey, sticky), oily cooked smooth rigatoni noodles (slippery, oily), and live earthworms (squishy, wriggling). The nondisgusting and unpleasant object (control) was a 7 cm diameter disk with screws glued to it in every direction (sharp). The neutral objects were three small raw wooden blocks (3.8 cm each dimension) and room-temperature water. Two positive objects were a round smooth wooden ball (5 cm diameter) and a bowlful of soft cotton pom-poms (3 cm diameter). There was variation in sample size across the measures. Fewer sessions were run that included earthworms (n = 37, 24 women) when the worms died and we were delayed in replacing them. All sessions included Honey and Noodles (n = 44, 29 women).
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Procedure After reading and signing the consent form, electrodes were situated for physiological recordings (not reported here). Participants gave a verbal response for their handedness to set up the box. On each of 8 trials, participants reached their dominant arm through an opening on the side of the box and put their hand in the bowl to feel the object. With their hand in contact with the object they used their non-dominant hand to record the sensory properties of the objects and their emotions, by using a thick-nibbed marker to make marks in the appropriate boxes. After each trial that involved water, honey, oily noodles, or worms, participants were given paper towels to clean their hand. We anticipated order effects, since encountering the disgust items might alter their expectations about future items. We created three pseudorandom orders (controlling what came first) and reversed them producing six different orders and assigned them randomly. To avoid alterations in reported disgust due to a mixed gender audience, male experimenters tested all the male participants, and female experimenters tested all female participants. After the last object, participants completed the EHI and DS-R.
Results Possible order effects were tested with 2 (gender) x 6 (orders) betweensubject MANOVAs on unpleasantness and disgust ratings. No significant effects were found at the .05 level so order will not be considered further. Both sets of unpleasant and disgust ratings for the three disgust-evoking stimuli (Worms, Honey, Noodles) were significantly intercorrelated (Table 1), and although the
TABLE 1. Correlation Coefficients for DS-R Scales and Disgust and Unpleasant Ratings 1 1. Worm Disgust 2. Honey Disgust 3. Noodle Disgust 4. Worm Unpleasant 5. Honey Unpleasant 6. Noodle Unpleasant DS-R total
.29
2
3
4
5
6
.72∗∗∗
.52∗∗∗ .38∗
.36∗ .44∗∗ —
.62∗∗∗ .75∗∗∗ .30∗ .55∗∗∗
.23 .25 .69∗∗∗ .34∗ .38∗
—
—
.20
.35∗
—
Note. Only r-values ≥ .20 listed. For Disgust and Unpleasant ratings df = 35 (Worms), df = 42 (Honey), df = 39 (Noodles); for DS-R measures df = 32 (Worms) and df = 39 (others). ∗ p < .05. ∗∗ p < .01. ∗∗∗ p < .001.
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Mean Unpleasant Ratings (0 - 8)
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8
Men
7
Women
6 5 4 3 2 1 0 Worms
Honey
Noodles
Screws
Water
Blocks
Round Pompoms
FIGURE 1. Mean unpleasantness ratings for all items. Ratings were from 0 (Pleasant) to 4 (Neither) to 8 (Unpleasant). Noodles = Oily Noodles. Round = Round Wood. Error bars based on standard error of the mean.
r-squared values were small to moderate (from .12 to .52) this finding suggests some consistency in response to the disgust-evoking items within individuals. Mixed ANOVAs were used to test the main hypotheses. When Mauchly’s test of sphericity was significant, Greenhouse-Geisser df corrections were used to adjust the p-values. An 8 (stimuli) × 2 (gender) mixed ANOVA found that the stimuli differed in their unpleasant ratings, F(7, 245) = 26.50, p < .001, partial η2 = .431, with Worms, Honey and Noodles, along with Screws all rated more unpleasant than the four neutral and positive items, all p < .001, except for the Noodles which were only slightly more unpleasant than the others p < .05 (Figure 1). No main effect for gender, F(1, 35) < 1, or interaction, F(1, 245) < 1, was seen supporting our predictions that the sensory aspects of the stimuli would not differ by gender. A similar mixed ANOVA used to assess disgust ratings showed a main effect for stimuli, F(7, 245) = 41.57, p < .001, partial η2 = .543 (Figure 2). Bonferroni comparisons revealed that Worms were not different from Honey but were rated higher in disgust than all other stimuli (all p < .001), including Noodles (p < .026); Honey was not different from Noodles, but was rated as significantly more disgusting than all other stimuli (all p < .001); and Noodles was rated more disgusting than Screws (p = .001) and the neutral and positive stimuli, all p < .001. There was no overall effect of gender, F(1, 35) = 2.51, p = .12, partial η2 = .067, but the
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*
Mean Disgust Rating (0 - 8)
Men
*
5
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Women
4
3
2
1
0 Worms
Honey
Noodles
Screws
Water
Blocks
Round
Pompoms
FIGURE 2. Mean disgust (“Grossed out”) ratings for all items. Ratings were from 0 (Low) to 8 (High). Noodles = Oily Noodles. Round = Round Wood. Error bars based on standard error of the mean. ∗ p < .05 for differences between men and women.
interaction between gender and stimuli was significant, F(2.99, 104.69) = 2.70, p = .05, partial η2 = .072. Independent t-tests with corrected degrees of freedom were used for to adjust the p-values when Levene’s test for equality of variances was significant. These tests showed that women’s rated disgust was higher than men’s rated disgust only for Worms, t(34.99) = 2.66, p = .012, d = .77, and Honey, t(42) = 2.03, p = .049, d = .64 (Figure 2). As predicted, differences between men and women were found when touching unseen disgust-evoking stimuli (Worms, Honey). No gender difference was found for the Noodles, which was the least disgust-evoking of the three stimuli. Participants were asked to name the objects after they recorded their responses, and these labels may have affected their disgust responses. While 48.6% of the participants thought they were touching worms, 13.5% of participants thought the worms were “gummy worms” or “candy worms” when trying to identify the stimuli. Since these are positively valenced categories, we reanalyzed the t-test for Worms after dropping those participants, which revealed a larger gender difference, t(25.09) = 3.58, p = .001, d = 1.27. Dropping these participants had no effect on mean unpleasant rating for Worms. Overall, the disgust-evoking objects showed different trends in recognition accuracy. Noodles were the most identifiable object, and no gender differences in the percent recognized were evident (73% by men,
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77% by women). Gender differences were seen for the other two stimuli, with a trend for men to better recognize they were touching worms (69% versus 37.5%, p = .09, Fisher Exact Test), and women were significantly better at identifying honey (38% versus 6.7%, p = .035, Fisher Exact Test). It was clear that the unpleasantness of the feel of the stimuli was related to the disgust one felt from the stimuli, as unpleasantness and disgust were significantly correlated for each disgust-evoking stimulus, Worms: r(35) = .36, p = .031, Honey: r(42) = .75, p < .001, Noodles: r(42) = .69, p < .001. Interestingly, running another set of correlations between disgust ratings of the stimuli and any of the other sensory ratings (Wet/Dry, Mushy/Solid, etc.) besides unpleasantness, found no significant correlations for the three disgust stimuli. Overall, no sensory aspect during contact with the stimuli was related to disgust feelings except for how unpleasant the stimuli felt. Women reported significantly higher disgust sensitivity measured with the DS-R, Mmen = 1.76, SD = 0.19, Mwomen = 1.96, SD = 0.24, t(39) = 2.73, p = .009, d = .90. However, contrary to our hypothesis that people higher in disgust sensitivity would rate their disgust higher in response to touching the disgust-evoking stimuli, we did not find a strong relationship in this regard. Correlations (Table 1) between mean DS-R scores and its subscales with rated disgust for each item indicated only a moderate relationship between disgust sensitivity and Honey disgust. If the DS-R was entered as the sole predictor of the disgust ratings, it accounted for 8% of the variance in Worm disgust (β = .289, t = 1.71, p = .09), 12% of the variance in Honey disgust (β = .346, t = 2.29, p = .027), and zero variance for Noodles disgust.
Discussion This study examined gender differences in disgust using a haptic task where we could assess both sensory qualities of the disgust-evoking stimuli and the resulting affective responses. We found predicted gender differences in disgust responses to the stimuli, but no gender differences in ratings of the sensory qualities of the stimuli. Women rated their disgust higher than men for the two most disgustevoking stimuli (Worms & Honey) but were not different from men when asked to rate how unpleasant the items felt. We successfully showed that the designated unpleasant stimuli (Worms, Honey, Noodles, Screws) were more unpleasant than the designated neutral (Blocks, Water) or positive stimuli (Round, Pompoms), and that the designated disgust-evoking objects produced higher-rated disgust than the other five stimuli. The sensations we tried to produce, such as stickiness, sliminess, oiliness, appeared to have successfully evoked disgust-related feelings in the participants. Our results also suggest that variation in participants’ ratings of oiliness, stickiness, wetness, etc. were not separately influential determinants of disgust levels. Rather, a Gestalt of the suite of characteristics may be necessary to
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generate imagery of the contacted stimulus that could be the greater determining factor for generating disgust. Are there gender differences in haptic abilities that may contribute to or explain our results? The evidence for gender differences in haptic abilities is mixed, with most studies finding no strong gender differences in manual touch of objects (e.g., Fagot, Lacreuse, & Vauclair, 1993; Robert & Chevrier, 2003). Some studies do find men to be more accurate in haptic tasks (e.g., Cohen & Levy, 1986; Zuidhoek, Kappers, & Postma, 2007). It is unclear if men do have an advantage, how that would explain their affective responses. We found that men were better at identifying they were touching worms than women, but not as good at identifying honey. The directionality of these identification differences did not directly translate into differences in disgust, so it is unlikely that gender differences in haptic skills underlies the gender differences seen in disgust responsiveness. Why should touching sticky and wormy things produce different levels of disgust in women and men? Our results suggest that the unpleasant nature of the stimuli produced similar ratings in men and women, so separate affective processes are likely responsible for the observed differences. We cannot determine whether biologically based differences in thresholds to respond with disgust differed in men and women. It could be that men and women both rate a 6 for unpleasantness to touching worms, but a 6 in women generates a disgust response but it takes a higher value, such as an 8 for men. Alternatively, the differences in disgust between men and women may be truly minimal, but that gender role expectations drive women to be more expressive about disgust and men to be less expressive about disgust (Skolnick et al., 2013). We have also argued that gross-out disgust should be considered a powerless emotion that could make men appear weak and less manly. Thus, men may be motivated to show themselves to be low in disgust to meet with masculine expectations (Skolnick et al., 2013). Our results are consistent with this view, as the men rarely gave high ratings to the disgust objects. In the current study, we tried to avoid this trend by always having male experimenters conducting the sessions with male participants. However, we cannot completely rule out an audience effect because men may be motivated to appear masculine by suppressing their disgust reactions in front of other men as well as women. Future paradigms designed to remove audience effects from haptic research would be helpful in determining whether men possibly suppress their disgust in front of others. That women were more disgusted than men for the two most disgust-evoking stimuli lends support to the alternative theory that women should be higher in disgust to protect their reproductive interests (Curtis et al., 2011; Fessler et al., 2004). Being more disgust sensitive to the touch of certain objects would fit with the protective role a mother adopts during childrearing. Oum and colleagues (2011) suggested the touch qualities that normally induce disgust (e.g., wetness, sliminess) might be cues to pathogens. Thus, this heightened avoidance of pathogens could be an underlying mechanism producing greater disgust in women from touching
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tactile indicators of decay and disease. Future studies should examine specific tactile cues that may be more or less likely to be indicators of pathogen presence to examine whether women showed heightened disgust to the former stimuli. Oum and colleagues has made the first attempt investigating wetness and temperature, but no gender differences in disgust based on these cues were found apart from women being more disgusted than men at the thought of putting the disgustevoking items in their mouth. It may be noted that the current participants were typical young college students and not parents. It is possible that increased tactile exposure to disgustevoking body products that come with raising an infant (e.g., feces, spit-up, mucus) may alter one’s levels of disgust when touching stimuli. Thus, it may be important to examine tactile disgust in a population of new parents to establish whether such experiential effects influence the size and direction of gender differences in disgust. We predicted that people higher in trait disgust sensitivity, as measured by the DS-R, would show higher disgust to the three disgust-evoking stimuli. However, unlike Oum and colleagues (2011), we did not find that disgust sensitivity was very predictive of the disgust ratings to the touched stimuli (Table 1). The DS-R was significantly related to Honey disgust but only showed a marginally significant trend with Worms (likely due to limited sample size given an r-value of .29) or Noodles. The Noodles were only somewhat disgusting for most people, so it may be appropriate that DS-R scores were not predictive of Noodles disgust ratings. Our data were aligned with Woody and Tolin (2002) who found that with behavioral tasks that evoke disgust, the Disgust Scale was not as strong a predictor of avoidance of disgusting tasks as state disgust (although the one stimulus that DS was predictive of was touching worms). The disgust-evoking qualities of the stimuli may have been intense enough that whether one was low or high in disgust sensitivity, the stimuli generated disgust regardless. One last limitation of the use of the DS-R was that participants filled it out after touching the objects, and its score may have been influenced by the touch session. We chose to present the survey afterward to avoid the survey alerting participants about the target emotion of interest because we did not want their disgust responses to be biased, as is possible if the DS-R scale is given first. We did find the typical large gender difference on the DS-R (Druschel & Sherman, 1999; Haidt et al., 1994; Quigley et al., 1997), suggesting no obvious biases occurred due to the order of presentation. An interesting aspect of the phenomenon of touch-induced disgust is the fact that the touch forces contact with something that a person finds aversive and would want to withdraw. Therefore, a possible limitation of our study was the use of the box to hide the stimuli from view. By making participants touch unseen objects, we were forcing them to imagine what they were touching and think about the identity of the object. Some people had accurate ideas about the objects and some had inaccurate ideas or no ideas. Thus, there may have been variation in the sources
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of information that cued their disgust feelings. We did find that people thinking they were touching candy-style worms gave much lower ratings of disgust than people thinking they were touching actual worms. This variability in imagery of what is being touched could possibly alter the relationship between a person’s disgust sensitivity and disgust ratings based on tactile contact. Individual differences in imagery abilities have also been seen to influence emotion-evoked arousal, with better imagers showing greater arousal from viewing affective pictures (Lang, Greenwald, Bradley, & Hamm, 1993). The role of additional sensory cues besides haptic cues may also aid in understanding how gender differences in disgust manifest when touching a stimulus. For example, visual cues prior to touch could either enhance the affective feelings with contact (e.g., if there are visual cues making the stimulus appear disgust-evoking) or lessen the affective feelings (e.g., if the appearance of the stimulus does not alone evoke disgust). Further research on haptic cues to disgust may profit from comparing haptic-only cue conditions (that likely instigate imagery) to haptic plus visual cue conditions (that do not require imagery). Rozin and colleagues (1999) and Woody and Tolin (2002) used visible stimuli for tactile-induced disgust but did not have tactile-only conditions for comparison. In conclusion, when offered an unseen sticky, slimy, or oily stimulus, men and women responded similarly when asked about how unpleasant or pleasant something feels, but they responded differently when asked how disgustedly “grossed out” they felt. Women scored higher on the Disgust Scale than men and also rated two of the three disgust items higher in disgust than men. For the third item, oily noodles, women’s levels of disgust were lower than for Worms and Honey and were equal to men’s levels, which were more uniformly low. An unpleasant item, a disk of somewhat sharp screws, produced little disgust for either gender, thus showing that disgust was not the result of an item being merely unpleasant to the touch. We also found that sensory qualities of the stimuli, other than how unpleasant it felt, did not vary with how disgusting one felt touching the item. We did not find an expected strong relationship between a person’s disgust sensitivity and their disgust ratings in the task. Further research is required to elaborate on the relationship between a person’s trait levels of disgust and their responses to disgust-evoking stimuli. Understanding the nature of gender differences in disgust uncovered here adds to our understanding of the ways men and women process emotional stimuli differentially. AUTHOR NOTE Alexander J. Skolnick, is in the Department of Psychology at Saint Joseph’s University in Philadelphia, PA. REFERENCES Brody, L. R. (1999). Gender, emotion, and the family. Cambridge, MA: Harvard University Press.
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Original manuscript received September 7, 2012 Final version accepted February 28, 2013
