Although ethologists have detailed courtship rituals for many species, courting behavior of humans has not received extensive study from an ethological standpoint. Yet there are clearly facial expressions and gestures that are commonly labeled "flirting behaviors." These nonverbal signals have been documented recently by several investigators in field studies, but the receptivity of nonverbal courtship signals is still in question. The current research project attempted to assess the perceptual skill of naive male and female observers who were presented videotaped samples of females' nonverbal courtship and rejection behaviors and asked to rate their intensity. The results showed that overall, men rated invitational behaviors more positively than women. In contrast, signals of rejection were seen by men as sending a less potent message than that perceived by women. Evolutionary theory may offer a framework for understanding these results.