Cognitive capacity of non-human primates has become a popular topic in rece
nt years. Humor is an important indicator of mental function. For the four
stages of humor development in children: 1.) inappropriate action. 2.) inco
ngruous labels. 3.) incongruous features. and 4.) multiple word meanings, e
xamples are presented from ape behavior. Apes appreciate and produce humor
in a manner comparable to humans.