The Three-Domain Disgust Scale, originally developed to capture the idea that disgust is not a single dial but three, distinguishes pathogen disgust, sexual disgust, and moral disgust. Pathogen disgust is the familiar protective reaction to contamination cues such as spoiled food, bodily waste, or visible infection. Sexual disgust is thought to regulate choices of mates and sexual behavior, steering people away from biologically costly or socially inappropriate partners and acts. Moral disgust, by contrast, extends the same visceral rejection to violations of social and ethical norms, from dishonesty to cruelty. The theory behind the scale predicts that these three domains, while related, should behave as separable psychological systems with different correlates, and testing that prediction rigorously in a new language and culture is exactly what the Ghent team set out to do.

The study’s design gives it unusual statistical muscle. In a first study of 991 participants and a second, larger study of 1,806, the researchers subjected the Dutch TDDS to confirmatory factor analysis, a technique that tests whether the pattern of answers people give matches a theoretically specified structure rather than emerging haphazardly. Across both samples, the analyses supported the theorized three-factor solution, with items loading on their intended domain and with acceptable global fit indices. In plain terms, when Dutch-speaking respondents answered questions about moldy food, unusual sexual practices, and morally repugnant behavior, their responses clustered into three coherent and largely independent dimensions, just as the three-domain framework predicts.

That structural result matters, but it is only the first hurdle. A scale could produce three neat factors and still measure something different for men than for women, which would make any comparison between the sexes meaningless. To rule this out, the authors tested measurement invariance, a demanding psychometric requirement that the scale’s items relate to the underlying disgust constructs in the same way across groups. In the second study, invariance across sex was fully supported at every level tested, and in the first study it was approximately supported. This means that when a man and a woman receive different scores on the Dutch TDDS, the difference can be interpreted as a genuine difference in disgust sensitivity rather than an artifact of the instrument functioning differently for each group.

With that foundation in place, the study turned to one of the most debated questions in disgust research: do men and women actually differ? The answer, in this dataset, is nuanced. Women showed reliably higher latent levels of sexual disgust, a difference that emerged consistently across both samples once measurement was held constant. By contrast, sex differences in pathogen disgust and moral disgust were smaller and depended on the sample, appearing in one dataset but not robustly in the other. The pattern fits evolutionary accounts that place particular emphasis on sexual disgust as a mechanism shaped differently in the two sexes, while cautioning against sweeping claims of broad female superiority in disgust sensitivity. The largest and most consistent sex difference is domain-specific, not global.

Perhaps the most scientifically consequential part of the paper is its examination of what the three disgust domains actually predict. The researchers examined associations with constructs including pair bonding, a measure labeled Low Morality reflecting self-reported immoral tendencies, and Outgroup Avoidance, reflecting avoidance of people from other groups. The results were strikingly selective. Sexual disgust was robustly linked to pair bonding across both studies, consistent with the idea that people high in sexual disgust invest differently in committed relationships and hold stricter boundaries around sexual behavior. Moral disgust, meanwhile, was substantially and negatively associated with Low Morality: individuals who report more immoral tendencies score lower in moral disgust, exactly the inverse relationship theory would anticipate if moral disgust functions as an internal guardian against norm violations.

Pathogen disgust told a different and more complicated story. Rather than relating broadly to everything, it showed selective associations, including a consistent positive link with Low Morality and weaker, sample-dependent relations with Outgroup Avoidance. The connection between contamination sensitivity and intergroup avoidance is a flashpoint in the literature, with some theorists arguing that pathogen disgust evolved partly to keep people away from unfamiliar others who might carry novel diseases, and others warning that such claims overreach. The Dutch data lend cautious support to the middle ground: the association exists but is not stable enough across samples to be treated as a firm psychological law, and the authors’ decision to report it as sample-dependent is a model of restraint in a field where dramatic claims about disgust and prejudice often outrun the evidence.

The study also distinguishes between construct validity and criterion validity, a distinction that matters for anyone hoping to use the scale in applied research. Construct validity, the coherence of the scale’s associations with theoretically related variables, was well supported. Criterion validity, the ability of disgust domains to predict external outcomes, was only partly supported. Predictors of Low Morality were stable across the two studies, but predictions of Outgroup Avoidance were less consistent, varying between samples. For researchers, the practical implication is that the Dutch TDDS can be trusted as a measurement tool and used confidently in studies of moral and sexual behavior, while findings involving intergroup outcomes should be replicated before being treated as established.

Why should a psychometric validation of a questionnaire generate wider interest? Because disgust has become one of the most influential constructs in modern moral and political psychology. Disgust sensitivity has been linked in hundreds of studies to political conservatism, moral judgment, prejudice, hygiene behavior, and even responses to pandemics. Many of those findings rest on translated versions of scales whose measurement properties in the new language were never verified as thoroughly as they were in the original. The Dutch TDDS now provides Dutch-speaking researchers, a community that includes large research programs in the Netherlands and Flanders, with an instrument whose three-factor structure, sex invariance, and nomological network have been demonstrated in samples large enough to detect even modest effects. That is the kind of unglamorous groundwork on which entire literatures depend.

The paper also illustrates a broader methodological trend: the insistence on replicating psychometric findings across independent samples within a single publication. A single-sample validation can always be dismissed as a quirk of who happened to answer the survey. By showing that the three-factor structure held in a second, larger sample, that invariance conclusions were consistent, and that some associations replicated while others did not, De Buck and Pauwels have given the field an unusually honest picture of which parts of the three-domain model are bedrock and which parts remain provisional. The Dutch TDDS emerges as a reliable and valid instrument for capturing domain-specific disgust sensitivity relevant to moral, social, and intergroup processes, and the selective pattern of its external correlations suggests that the next generation of disgust research will need to be as precise about which disgust it is measuring as the scale itself now is.

Subject of Research: Psychometric validation of the Dutch Three-Domain Disgust Scale measuring pathogen, sexual, and moral disgust

Article Title: The Dutch Three-Domain Disgust Scale (TDDS): structural validity, measurement invariance, and nomological associations across two large samples

Article References: De Buck, A., & Pauwels, L. J. (2026). The Dutch Three-Domain Disgust Scale (TDDS): structural validity, measurement invariance, and nomological associations across two large samples. BMC Psychology. https://doi.org/10.1186/s40359-026-05703-y

Image Credits: AI Generated

DOI: 10.1186/s40359-026-05703-y

Keywords: disgust sensitivity, Three-Domain Disgust Scale, psychometrics, measurement invariance, confirmatory factor analysis, sex differences, moral psychology, pathogen disgust, sexual disgust, moral disgust, construct validity, Ghent University

Hygiene is a cornerstone of public health. Poor hygiene is closely tied to infection, disease transmission, and preventable illness, which is why public health researchers have long sought to understand the psychological drivers of behaviors such as handwashing, housecleaning, and personal grooming. Decades of work on disgust—the emotion thought to have evolved as a behavioral defense against pathogens—have established that people who are more easily disgusted tend to engage in more protective hygiene behavior. At the same time, olfaction has repeatedly been implicated in this picture: the sense of smell is our most direct chemical sensor of the environment, capable of detecting spoilage, contamination, and body odors that signal potential health threats.

The new research set out to connect these threads more rigorously. Rather than treating olfaction as a single, undifferentiated capacity, the team distinguished between olfactory metacognition—how people think and feel about their own sense of smell—and olfactory function measured objectively in the laboratory. The central hypothesis was that olfactory functioning relates to hygiene behavior at least partly through disgust sensitivity, the tendency to experience revulsion in response to potential contaminants. To test this, the researchers conducted two studies with distinct designs and measurement approaches.

Study 1 recruited 270 participants and focused on three indicators of olfactory metacognition: odor awareness, the subjective importance people attach to their sense of smell, and self-rated olfactory ability. Each of these indicators was positively associated with self-reported hygiene behavior. Crucially, when the researchers used mediation analysis to examine indirect pathways, each indicator showed a significant indirect effect through disgust sensitivity. In other words, people who were more attuned to odors, who valued their sense of smell more highly, and who rated their olfactory ability as stronger also tended to report higher disgust sensitivity—and that heightened disgust, in turn, was associated with more frequent and thorough hygiene practices.

These findings align with a conceptual framework in which disgust functions as part of the so-called behavioral immune system, a suite of psychological mechanisms that guard against disease threat before pathogens ever reach the body. According to this view, sensory inputs—especially smells—provide cues about potential contamination, and disgust converts those cues into avoidance and cleaning behavior. The Study 1 results suggest that individual differences in how prominently smell figures in daily awareness may shape the intensity of this disgust-based defense, and thereby the vigor of one’s hygiene routine.

But subjective self-reports are not the same as measured sensory ability. Study 2 therefore extended the investigation with 66 participants who completed psychophysical odor-threshold testing and suprathreshold ratings for one pleasant and one unpleasant odor. This design allowed the researchers to ask whether the ability to detect faint odors—rather than merely one’s beliefs about one’s own nose—also relates to hygiene behavior, and whether the valence of the odor matters. The results were more nuanced here. Odor sensitivity itself was not directly associated with hygiene behavior, a finding that echoes earlier work suggesting that disgust sensitivity relates to affective responses to odors rather than to the raw capacity to detect them.

Yet the indirect pathway through disgust sensitivity did appear in Study 2, though selectively. A significant indirect effect through disgust sensitivity was observed for the pleasant odor but not for the unpleasant odor. That an unpleasant smell failed to show the same pathway may seem counterintuitive, but the authors caution that a bootstrap comparison did not support a statistically reliable difference between the two indirect effects. In other words, the apparent pleasant-versus-unpleasant asymmetry at the threshold level should be interpreted with care, as the data could not confirm that the two odor conditions truly differed in the strength of this mediated pathway.

Where odor-condition differences did emerge clearly was at the suprathreshold level—when participants judged clearly perceivable odors. The associations of hygiene behavior with odor pleasantness and familiarity differed significantly between the pleasant and unpleasant odor conditions, with positive associations observed specifically for the pleasant odor. This suggests that how people appraise and contextualize everyday smells—their emotional coloring and their sense of familiarity—may relate to hygiene behavior differently depending on the hedonic character of the odor in question, whereas simple detection ability appears less consequential.

Taken together, the two studies paint a differentiated picture: subjective and psychophysical aspects of olfactory functioning are related to hygiene behavior in partly different ways. Disgust sensitivity emerges as one affective correlate of these associations, providing a plausible psychological route by which smelling and thinking about smells translates into washing, cleaning, and grooming. Meanwhile, odor valence effects were more clearly supported for conscious appraisal of suprathreshold odors than for basic odor sensitivity, implying that the emotional meaning of smell, rather than the acuity of the nose per se, drives much of the connection to hygiene.

The findings carry practical weight for public health. If disgust sensitivity mediates the link between olfaction and hygiene behavior, interventions aimed at improving hygiene might benefit from strategies that engage the sense of smell and the emotion of disgust together—approaches that earlier experimental and field-based work on hand hygiene has begun to explore. At the same time, the authors emphasize limits: the indirect pathway was not uniformly observed across odor conditions, the pleasant-versus-unpleasant asymmetry in threshold-based mediation was not statistically reliable, and the data underlying the study will be shared only on reasonable request to the corresponding author. Future research with larger and more diverse samples will be needed to determine when, and for whom, the nose-disgust-hygiene pathway operates most strongly—and whether it can be harnessed to promote healthier behavior at the population scale.

Subject of Research: The relationship between olfactory functioning, disgust sensitivity, and hygiene behavior

Article Title: Disgust sensitivity as an indirect pathway linking olfactory functioning and hygiene behavior

Article References: Jiang, C., Modi, U., & Han, P. (2026). Disgust sensitivity as an indirect pathway linking olfactory functioning and hygiene behavior. Current Psychology, 45(17), Article 1487. https://doi.org/10.1007/s12144-026-10057-0

Image Credits: AI Generated

DOI: 10.1007/s12144-026-10057-0

Keywords: olfaction, disgust sensitivity, hygiene behavior, odor awareness, olfactory metacognition, odor threshold, odor valence, behavioral immune system, public health, psychology, sensory perception, handwashing