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3 DISCONFIRMING CONTAMINATION-RELATED THREAT BELIEFS 69 METHOD Participants Participants were recruited using posters, flyers and online advertisement on the university website. A total of 297 students were screened for contamination fear with the Padua Inventory - Contamination Obsessions and Washing Compulsions subscale (PI–COWC; Burns, Keortge, Formea, & Sternberger, 1996; see 2.3.1). Individuals who scored 3 or higher ( n = 225, above the lowest-quartile range, to decrease the likelihood that participants had to be excluded after the pre-test, see 2.2.1) and indicated willingness to participate ( n = 180) were invited to participate, of whom 103 agreed to make an appointment. Exclusion criteria were past or current OCD diagnosis ( n = 1); contamination scores for all six contaminants (see 2.4) at the pre-test below 60 ( n = 11, cf. van den Hout et al., 2011); and a score below 60 for the threat belief at the pre-test ( n = 25; see 2.2.1), because this indicated that participants considered their threat belief largely unbelievable. This resulted in a final sample of 66 participants (13 men; M age = 21.68, SD = 2.95; M PI-COWC = 8.89, SD = 5.54), who were randomly assigned to the E+RP ( n = 22; 4 men), E+SB ( n = 22; 5 men), or control ( n = 22; 4 men) condition. Participants gave written informed consent and received money or course credit for their cooperation. Procedure The procedure for session 1 by van den Hout et al. (2011; see also Rachman et al., 2011) was replicated, with the addition of the identification of a threat belief and rating it at the pre- and post-test. Pre-test measurement The contaminant (see 2.4) that evoked the highest feeling of contamination was selected as the contamination stimulus for the experimental trials (see van den Hout et al., 2011, Baseline measurement). The experimenter put the contaminant in front of the participant and asked “What did you feel when you just touched this object? Can