Few experimental studies have provided evidence of a causal link between a root variable and the observed variation in willingness to trade (WTA). We suggest that the source of this variation is at least partially to be found in fear of negative evaluation (FNE). To support this hypothesis, we manipulated FNE in a group of college students and assessed their willingness to trade. In Experiment 1, the participants in the high-FNE group demonstrated a greater reluctance to trade than did those in the low-FNE condition. Furthermore, chronic levels of FNE were found to be negatively related to WTA. We suggest that FNE is one of the casual factors which explain differences in WTA between individuals. Other factors, which can be related to FNE and WTA, are discussed.