Man has been defined as the animal capable of laughter. Although this definition has been attacked by lovers of quadrupeds, it has held in the minds of thinkers and students. Aristotle, Milton, Hazlitt, Voltaire, Schopenhauer, Bergson and many other distinguished scholars hold that the playfulness seen in animals is in no way an indication of their sense of humor.
The Laughing Hyena and the Laughing Jackass are so called only because their cry has a likeness to the sound of raucous human laughter, but it is no result of mirthful feeling.
Hazlitt says man is the only animal that laughs and weeps, for he is the only animal that is struck with the difference between what things are and what they ought to be.
The playfulness of dogs or kittens is often assumed to be humor, when it is mere imitative sagacity. The stolid, imperturbable gravity of animals’ faces shows no appreciation of mirth.
Oliver Wendell Holmes speaks of the large brown eyes of oxen as imperfect organisms, because they may show no sign of fun.
Yet it is, in a way, a matter of opinion, for the instinct of humor was among the latest to evolve in the human race, and rudimentary hints of it may be present in other animals as in our own children. A monkey or a baby will show amusement when tickled, but this is mere physical reflex action, and cannot be called a true sense of humor.
Many animal lovers assume intelligences in their pets that are mere reflections of their own mental processes or are thoughts fathered by their own wishes.
It is, however, of little importance, for however appreciative of fun an animal may be, it cannot create or impart wit or humor, and most certainly it cannot laugh.
Bergson goes even farther. He declares the comic does not exist outside the pale of what is strictly human.
He states: You may laugh at an animal, but only because you have detected in it some human attitude or expression.