Two studies are reported concerning implicit theories of intelligence. The first study replicated procedures employed by Sternberg, Conway, Ketron, and Bernstein (1981). Factor analysis of importance ratings of intelligent and unintelligent behaviors suggested a simpler model of implicit theories than suggested by Sternberg et al. However, the use of importance ratings for examining implicit theories was challenged because the results proved ambiguous. The second study used a sorting procedure to produce similarity data. Multidimensional and tree scaling solutions indicated that the primary distinction in implicit theories was between intelligent and unintelligent behaviors and that important distinctions were not made among intelligent behaviors. In general, the data suggested that implicit theories of intelligence are much simpler than most formal theories used in psychology.