To test the mere exposure hypothesis, subjects were exposed to 20 slides of black and white stimulus persons. Based upon pre-experimental ratings, each slide had been initially assigned to one of four groups: high favorable black, high favorable white, low favorable black, and low favorable white. The experimental group, consisting of 25 white male subjects, received the exposure treatment; the control group did not. Analysis of variance of the pre- and post-test favorability ratings of the experimental group revealed a significant exposure effect for both levels of favorability. Results indicated a significant exposure effect regardless of race of the stimulus persons. The exposure sequence equally enhanced the interpersonal favorability of both racial groups. No significant changes were observed for the control group. The results of the present study agree with the response competition view of the mere exposure effect, but disagree with the adaptation and classical conditioning explanations. (Author)