Thick terms and concepts, such as honesty and cruelty, are atthe heart of a variety of debates in linguistics, philosophy oflanguage, and metaethics. Central to these debates is thequestion of how the descriptive and evaluative components ofthick concepts are related and whether they can be separatedfrom each other. So far, no empirical data on how thick termsare used in ordinary language has been collected to informthese debates. In this paper, we present the first empiricalstudy, designed to investigate whether the evaluativecomponent of thick concepts can be separated. Our study mightbe considered to falsify the view that evaluation isconversationally implicated. However, our study also revealsan effect of valence, indicating that people reason differentlyabout positive and negative thick terms. While evaluationscannot be cancelled for negative thick terms, they can be forpositive ones. Three follow-up studies were conducted toexplain this effect. We conclude that the effect of valence isbest accounted for by a difference in the social norms guidingevaluative language.