This paper presents an experimental investigation of the causes and accuracy of adolescents' judgments regarding the likelihood of obtaining a high status occupation. High school students were asked to estimate the probability that a fictitious target subject would actually achieve the goal of becoming a doctor. Information about job availability and target subject characteristics were varied across experimental conditions. Three conclusions are indicated. First, high school students' probability judgments about high status career attainment are unrealistic. Second, probability judgments are responsive to the presentation of information about job availability, but on average such judgments are still unrealistic even when this information is provided to students. Third, probability judgments are distorted in a self-serving manner when the students who rate the odds of career attainment themselves aspire to that career. Findings suggest that adolescents may overaspire in their career expectations because they reason inaccurately about the difficulty of attaining high-status jobs. Implications for career counseling suggest that simply giving students labor market information may be insufficient to foster more realistic ideas about careers. The paper notes the need for a didactic technique that can impress upon students the logical relationship between frequency information and subjective degrees of confidence in the likelihood of single events. (Contains 11 references, 2 tables, and 1 figure.) (JDM)