Pedestrians in 12 diverse city environments were given a friendly greeting by a male or female investigator. Rates of eye contact, smiling, nodding, and speaking differed significantly across settings. The categorization of these settings in terms of pleasantness, information rate, and arousal-eliciting quality revealed a linear relationship between pleasantness and affiliative behavior, a curvilinear relationship between arousal-eliciting quality and affiliative behavior, and an interaction between pleasantness and arousal-eliciting quality. The results give strong support to a model proposed by Mehrabian and Russell (1974).