This research examined whether the better-than-average (BTA) effect is a possible explanation for norm misperceptions. Data from an online study demonstrates that people perceive their risk and proenvironmental behavior as more socially approved than the same behavior in others, suggesting that norm misperceptions are driven by the BTA effect. This suggestion is further substantiated by the observation that when a proenvironmental lifestyle is important to a person, that person’s perception that their proenvironmental behavior is more socially approved of than the same behavior in others becomes more pronounced. This moderator effect of importance is typically reported in the BTA literature. Norm misperceptions were also more pronounced when behaviors were framed in a socially disapproving manner when compared to those framed in a socially approving manner. This framing effect underpins that the BTA effect drives norm misperceptions. We expect that these findings advance the conceptualization of interventions based on social norms and contribute to BTA literature.