Past research suggests positive affective states promote state authenticity. However, in those studies, positive affective states are confounded with approach motivation, leaving some ambiguity in what is driving such effects. To address this limitation, we studied the effect of anger—a negative affective state related to approach motivation—on state authenticity. In two experiments (total N = 824), we experimentally induced different affective states (via movie-clips in Study 1 and autobiographical recall in Study 2) and had participants report state authenticity thereafter. We compared the anger condition to an amusement condition (Study 1), a fear condition (Studies 1 and 2) and a disgust condition (Study 2). We also measured affective valence and approach states in Study 2 to test for mediation. The results revealed that anger reduced authenticity relative to amusement but did not differ from fear or disgust. Moreover, an indirect effect of affective valence (but not approach states, Study 2) emerged: anger made people feel less pleasant, which explained their lower state authenticity. These findings suggest that affective valence is more important to state authenticity than approach/avoidance motivation.