A nursery school teacher brought a little girl to a psychologist’s attention when the girl was being made the focus of contemptuous looks by her peers and playmates. “Why do they look at her that way?” asked the teacher. “She’s attractive and bright and she wants to play with the other children.” The psychologist looked over at the child. “What little girl?” she asked. “That’s a boy.” The psychologist was wrong and that was the problem. This 4-year-old girl had the lower brow ridge of a boy, the smaller mouth and the gestures of a boy. She did not often smile; she stood obliquely and she gestured expansively. She engaged in rough-and-tumble play. She also nurtured dolls and was learning to read early. The children in playschool did not know what to make of her. The adults said, “There’s something strange about the nice child over there, but I can’t quite put my finger on it.” That last sentence sums up what our research in nonverbal behavior is all about. We are putting our fingers on the important things that people have few words for—the barely conscious gestures that separate and identify the sexes.