[영문]We used a random-digit-dialed survey of 434 smokers to demonstrate that approximately three quarters of young adult (aged 19?24 years) smokers overestimated by 20% or more the proportion of their peers who smoked. The effect of this normative fallacy was significantly greater in young adult smokers than in smokers aged 25 years or older. Because of the strength of this false consensus effect in young adult smokers, normative feedback interventions might be especially effective in this age group