Examination of a bifactor model of the Three Domains of Disgust Scale: Specificity in relation to obsessive-compulsive symptoms.

The current research evaluated a bifactor model for the Three Domains of Disgust Scale (TDDS) in 2 undergraduate samples. The goals were (a) to evaluate whether the TDDS should be scored as a unidimensional scale or whether subscales of pathogen, sex, and moral disgust should be additionally interpreted, and (b) to examine the utility of the TDDS subscales above and beyond the total score in predicting obsessive-compulsive disorder (OCD) symptoms. Results in Study 1 and Study 2 revealed that a bifactor model fit the TDDS data well and that all items were influenced by a general disgust dimension and by 1 of 3 content dimensions. However, model-based reliability estimated via omega hierarchical for the total score suggested that TDDS items are highly multidimensional. That is, the general disgust dimension only accounts for about half of the variability in the items of the total score, with the remaining variability accounted for by the specific disgust domains and other sources of variance. Despite the high degree of multidimensionality underlying the TDDS items, the pathogen and sex subscale scores were found to be relatively unreliable after controlling for the general disgust factor. Among the 3 domains, pathogen disgust had the most consistently significant relationship with an OCD symptom latent factor above and beyond the general disgust factor. The strengths and limitations of the TDDS are discussed in the context of these findings, and the implications for better understanding the structure of disgust and its relationship with OCD are outlined.