The following train of thought wreaked through my brains while I was having a lunch time discussion with my fellow colleagues.
Joke as a consequence of classification
All jokes appeared to be based on some form of classification. I couldn’t think of a joke that wasn’t rooted in classification. In case of a racial, gender or “Your mama’s so fat…” jokes, the classification is very apparent. (In case you didn’t get the classification of the last one, it is anatomical.) However, there are other classes of jokes for which the classification is not so straight forward.
Homonyms and puns superficially seem to allude the former group. However, it can be argued that the semantics of the various possibilities form an intrinsic set of classes. For example, in the sentence, “Atheism is a non-prophet institution”, the intrinsic classes are profit and prophet. A listener should have prior knowledge to decode this classification. Failure to do so, will cause the joke to rot in hell. Such intrinsic classification is inherent in most jokes that uses some kind of linguistic property.
Joke or Jealousy?
The classification theory started to fall apart when Rueben (the same colleague who had visited Mosque Road  and Samarkand  with me) pointed out a great problem associated with the theory. What if the classification causes a desire to acquire the attributes of the other class?
Let us take the case of “Your mama’s so fat…” construct. This classification of fat vs lean body need not necessarily create a joke. I can construct one which goes like this – “Your mama’s so thin that she got hired as a zero-sized model.” It is no more funny. Here lies the catch. It is no more funny to people who think that being fat is not a desirable trait. It could be funny to people who view being anorexia as a less than desirable trait .
Thus we come across the second fundamental necessity to construct a joke. The audience must find the outcome of the classification to be inferior. Otherwise, they might form a desirable trait. For example, let’s take the Indian society fixated on fair skin. I bet most people in India would laugh at “Your wife’s so black…” jokes. This is what fuels the sales of a strange cosmetic product called Fair & Lovely . I am sure that the husband would not find it amusing at all.
Thus a hierarchical stratification of classes that are obtained as a result of classification is necessary. It may lead to a joke or it may lead to jealousy. Assuming that the husband in the previous example is sensible, he would not be bothered by such silly remarks. Thus, even if he has accepted the classification (fair and dark both exist) but refuses to hierarchically stratify the classes (fair is superior to dark or vice versa) will not find the joke funny.
Let me address another question. What about self-depreciating humour? The necessity is that the audience must find the class to be inferior and not the person delivering the joke. No wonder that “misfortune”, a less than desirable outcome in most self-depreciating jokes, finds the most amount of laughs in a stand-up comedy routine.
Does that affect the puns?
Actually, even jokes that rely on wordplay require the hierarchical stratification of classes. It is necessary that the audience does that exercise on the various semantic outcomes of such statements. The laugh ensues when they hit upon the one that is absurd. For most people, the hierarchy is something like reality is better than the impossible, which in turn is better than the improbable.
Note: I will be more than happy to entertain counter examples. I sincerely doubt if my two hour thought process would topple the centuries old study on theories of humour .