Some decision situations are so objectionable or repugnant that people refuse to make a choice. This paper seeks to better understand taboo responses, and to distinguish choices that are truly taboo from those that are merely difficult or confusing. Using 22 scenarios that describe potentially taboo issues, Experiment 1 explores reasons for disapproval of the scenarios. We measure a large number of possible reasons for disapproval and a variety of preference responses (including willingness to accept), in order to test for subtleties in taboo responses. We also test cognitive and affective responses to the scenarios. Experiment 2 further explores the interaction, found in Experiment 1, between affective and cognitive factors. Taken as a whole, our results show that people are able to indicate their disapproval consistently across a variety of preference elicitation methods, that their disapproval is better understood as an attitude measure than as an economic valuation (even when the measure is in monetary terms), and that taboo responses are driven primarily by affect.