Kindergarten is a triumph of sexual self-stereotyping,"" this highly observant book begins. The children ""think they have invented the differences between boys and girls. . . and must prove that it works."" As perceptive as White Teacher (1979) and Wally's Stories (1981), this looks closely at themes and patterns in kindergarten children's play and at Paley's responses to them. Once past nursery school, even in an apparently non-sexist environment, girls and boys play differently. Girls tend to draw, to play school or family, while boys more often build with blocks or play superheroes. Paley does not venture into the sources of these separate styles, but she finds that her attempts to alter the play fail unless they mesh with the fantasies these games reflect. Neither girls nor boys necessarily lose out, she believes; girls learn to draw what boys build in the block corner, approaching a mastery of spatial arrangements via different routes. Paley is a sharp interpreter of common incidents--Barbie dolls make little girls blush--and their implications; she is just as valuable, and refreshingly honest, in reporting her own not always consistent reactions. She finds, for example, that her level of contentment or anxiety is closely related to the mood of the boys: loose when they are calm, tense when their play turns wild. Although she admires their livelier style and group spirit and consciously hopes the girls will spice up their play, she is uneasy, even a bit put out, when some girls actually do develop a more active game. Moreover, at the end, she comes to the unexpected conclusion that her carefully planned curriculum suits girls better than boys. Readers who recognize the behaviors Paley describes will appreciate the quality of attention she brings to each scene and her capacity for shaping incident into idea.