Discussion: This study aims at expanding the understanding of mental contamination. First, the dirty kiss experiment is independently replicated in a Chinese population. Second, contact contamination and mental contamination are found to be separable and do not interact with each other. This underscores the independence of the two forms of contamination. Third, betrayal is shown to evoke mental contamination. Discussion has been made on the potential link between psychological violation, morality and mental contamination. / Mental contamination, an important phenomenon in OCD, refers to a sense of dirtiness without any contact with objectively dirty contaminant. However, the concept of mental contamination has not been thoroughly researched and there is an impending need for a psychological model to explain the phenomenon. / Method: Participants were assessed on questionnaires after imagining a non-consensual kiss or betrayal. / Objectives: The overall goal of this study is to enhance our understanding about mental contamination. Based on an experimental paradigm developed by Fairbrother, Newth, and Rachman (2005), three experiments are designed. The first experiment aims at replicating the results of the original study in local Chinese women. The second experiment examines the relationship between contact and mental contamination. The third experiment investigates the presence of mental contamination in persons experiencing betrayal. / Results: In Experiment 1, with an imagined non-consensual kiss, feeling of dirtiness, urge to wash and negative emotions were reproduced. In Experiment 2, it illustrated that either kissing a physically dirty looking man or being kissed non-consensually would experience stronger feeling of dirtiness, urge to wash and negative emotions. The last experiment showed that an imagined betrayal, a form of psychological violation, also induced a feeling of dirtiness, washing urge and negative emotions as with an imagined non-consensual kiss. / Three different pools of adult female participants were recruited for each experiment. In Experiment 1, 72 participants were recruited and randomly assigned to either a consensual kiss or a non-consensual kiss condition. In Experiment 2, 122 participants were recruited and randomly assigned to one of the four conditions. In Experiment 3, a total of 64 participants were recruited and randomly assigned to either non-betrayal or betrayal condition. / Kwok, Pui Ling Amy. / Adviser: Patrick Leung. / Source: Dissertation Abstracts International, Volume: 73-01, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 166-177). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract and appendixes 1-3, 5-8 also in Chinese.