The disgusting self: developing and validating an implicit measure of self-disgust

Self-disgust is a negative self-conscious emotion schema (Powell et al., 2015) that originates from the basic emotion of disgust but is directed to the self. Self-disgust can be directed towards the self, commonly referred to as self-disgust “self” (e.g., "I find myself repulsive") or to one’s actions, referred to as self-disgust “ways” (e.g., "I often do things I find revolting") (Overton et al., 2008). The concept of self-disgust as an emotion schema highlights the fact that it is a lasting cognitive-affective construct, that requires some level of self-awareness (Powell et al., 2015). There are two main measures for self-disgust, which are both self-report questionnaires; the Self-Disgust Scale (SDS; Overton et al., 2008) and the Questionnaire for the Assessment of Self-Disgust (QASD; Schienle et al., 2014). Although self-report measures can offer insight into the experience of self-disgust, there are several limitations to their use. The aim of the present PhD thesis was to develop and validate a new implicit association test (IAT) to measure self-disgust. To do so, a systematic literature review (Chapter 2) was conducted to understand the relationship between self-disgust and mental health difficulties in clinical and non-clinical populations. The development of the implicit self-disgust measure involved four studies. Study 1 (word validation study) used a sample of university students to validate a set of disgust-related words and happy words, matched for length. This process resulted in 27 word-pairs (disgust-happy) that were used subsequently in the development of the IAT. In Study 2, the newly developed IAT was validated in a sample of adults, which included two target categories (self and other) alongside two attribute categories (disgust and happy). Study 3 involved development and validation of a single-target IAT (removing the “other” target category) in a sample of healthy adults. Finally, Study 4, used the single-target IAT, in a population with post-traumatic stress disorder (PTSD) or trauma-related experiences, which is known to exhibit high levels of self-disgust. Overall, the findings from the four studies, suggest that self-disgust may not reflect automatic, implicit cognitive processes, as measured by IATs. Rather, self-disgust requires reflective processes that are more readily captured using self-report measures. An extensive discussion on the utility of IAT in the context of self-disgust and the limitations of the current thesis are presented in the last chapter.