116 children from grades junior kindergarten through three (ages 4–9 yr.) rated the funniness of five cartoon drawings depicting each of three types of humor (aggressive, body, and incongruous) and also explained why the cartoons were supposed to be funny. Understanding of funniness was not a function of age, but appreciation (rating) was. Appreciation increased significantly with age and types of humor were differentially rated (incongruous and body humor were rated higher than aggressive humor). Several interactions of type of humor with sex of subjects and grade were also significant. Ratings of all three types of humor were weakly correlated with personality adjustments as evaluated by the subjects' teachers on a standard instrument. The independence of the two response variables (understanding, appreciation) is noted.