The present theory dovetails nicely with certain biological observations. For example, the theory requires a simultaneous juxtaposition of two views in the mind for humor to be perceived. This makes the general cognitive point that only a relatively sophisticated mental apparatus, which can simultaneously entertain multiple views of a situation, is capable of perceiving humor. Certainly a mind that can entertain two views at once is more complex than one that can only entertain one interpretation at a time. This would seem to have some general relationship to the observation that only humans, chimpanzees, and possibly gorillas, orangutans, and even macaques laugh (Gruner, 1978:2-4), but that ``lower'' animals do not. Cognitive abilities of apes and monkeys exceed those of the lower animals; this general relationship is at least consistent with the theory's requirement of a relatively complex mind.