Two studies examined students' intuitive physics ability and characteristics associated with physics competence. In Study 1, although many students did well on a physics quiz, more than 25% of students performed below levels predicted by chance. Better performance on the physics quiz was related to physics grades, highest level of math taken, and students' perceived scholastic competence, but was not related to a number of other hypothesized personality variables. Study 2 further explored personality and academic variables and also examined students' awareness of their own physics ability. Results indicate that the personality variables were again unrelated to ability, but narcissism may be related to subjects' estimates of knowledge. Also, academic variables and how important students think it is to understand the physical world are related to both measured and estimated physics proficiency. © 2002 Wiley Periodicals, Inc. J Res Sci Teach 39: 394–409, 2002