Three experiments investigated the impact of anchors on students' estimates of personal alcohol consumption to better understand the role that this form of bias might have in social norm intervention programs. Experiments I and II found that estimates of consumption were susceptible to anchoring effects when an open-answer and a scale-response format were used. Experiment III utilized a design that communicated social norm information as a previous social norm intervention had done and found that self-reported binge drinking was reduced though actual consumption could not have changed. Implications for the use and assessment of social norm intervention as a component of alcohol education are discussed including the pessimistic possibility that social norm interventions may not be affecting students' actual consumption.