This study focuses on the motivational aspects of children's humor and describes the naturally occurring verbal humor of children without stimulus from adults. Kindergarten and elementary school children were observed during their lunch period at school while engaged in social interaction over 16 weeks. The study was designed to (1) record the types and frequencies of humor that appeared at each age level, and (2) determine the extent to which the emotional tone of the day affected humor production or reproduction. The findings of the study supported the developmental stages of humor outlined by Paul McGhee (1971). In all forms of humor, boys were the initiators and girls the responders. Girls were eager to laugh at boys' antics and jokes, while boys did not respond to girls' attempts to be funny. Very little hostile humor was found. Hostile humor occurred among boys after teasing was initiated by a boy, and a girl teased in return. More humor was recorded on days classified as high or medium in emotional tone (days when children would not settle down, or normal days) than on days classified as low in tone (quiet days with little interaction). Children in kindergarten and first grade engaged in more teasing and silliness than other children. (Author/SS)