The apparently divergent similarity-attraction findings of the reinforcement theory and uniqueness theory researchers were investigated by exposing male (N = 45) and female (N = 45) subjects to conditions of slight, moderate, or high similarity relative to one comparison other. Similarity was manipulated by means of a bogus personality and attitude inventory. For the self-report measures, results consistent with reinforcement theory were obtained in that greater self-reported attraction to the partner was linearly related to increased similarity. Additionally, interpersonal distance was curvilinearly related to similarity. This distancing pattern reflected the fact that moderate similarity subjects positioned themselves relatively closer to the other person's chair than the slight or high similarity subjects. The physical distance results support the uniqueness theory notion that high similarity may have some aversive properties. The discrepancy between the physical distance and self-report results is discussed in terms of an implicit causal theory that subjects may have about interpersonal similarity (i.e., greater similarity is good).