Victor Lvovich Porton
The author proposes the conjecture that sense of humor is a mean to protect from forming false associations and so is one of the most important components of human mind.
Keywords: humor, sense of humor, laughing, evolutionary psychology
Zigmund Freud presumed  that humor is a mean to “discharge” psychological strain. (The author doubts this “theory” because accordingly the opinion of the author evolution could not lead to creation a so complex system of discharging as humor, but rather to a less complex system of discharge.)
M. Choici  considered laughing a protective reaction against the fear of forbidden. A human, accordingly his opinion, using laugh overcomes the fear of father, mother, authorities, sexuality, aggressivity, and so on. I can provide the same critic against this theory as the theory of Freud.
Also it was supposed that laugh has social functions, such as “rectification of society” . Krishtafov I.A. brings forth the opinion, that humor may be a mean of psychological protective reaction against authorities .
Some scientists believed  that sense of humor is a “peacock’s tail” (a mean to demonstrate intellect), developed as a result of evolution for attracting partners of the opposite sex.
But I bring forth a radically different explanation of sense of humor, in which the sense of humor is one of the most important integral aspects of the psyche.
In this article is brought forth the following main conjecture:
Activation of sense of humor of a human blocks creation of associations. Blocking false associations is the main adaptive purpose of sense of humor.
The reason that people like to joke and watch comic plots for, is the necessity to train the sense of humor for effective blocking false associations (and not blocking correct associations).
In the case if the main conjecture turns out to be true, we probably underestimated importance of the sense of humor. Probably the sense of humor is not less and maybe even more important component of psyche of a rational being, that the ability to create associations, because for correct, effective thinking, it is necessary not only to create associations but also to block false associations. This by the way explains why for women the humor sense of their sexual partners is so important.
Such the underestimation is related to the fact that (in the case if the main conjecture is true), blocking associations when the sense of humor is activated, happens unconsciously. So we have no conscious feeling that associations are blocked when our sense of humor is activated.
Arguments pro the main conjecture
The reason that author supposes that the conjecture is true, is the following:
The situations when a human needs to prevent creation of false associations and the situations when a human experiences activation of sense of humor, are similar. Both situations appear when there are “proposed” false associations. This allows to support that activation of sense of humor does the thing necessary in such situations, that is blocks creations of false associations.
I will show an example: In Russian Internet there was popular a video movie about a cat raising on the hind legs “at attention”, when hearing the Russian hymn. This is undoubtedly a humorous situation. Accordingly my conjecture, the sense of humor in this situation blocks appearance of the false association “The cat is a patriot” that is introduction of a false idea into consciousness that this cat is patriotic.
This way presumably the sense of humor protects the mind of false ideas.
It is widely known that many mentally ill people have abnormal sense of humor, such as it being missing or reversely persistent laugh. In the framework of the proposed conjecture this can be explained by that damaged sense of humor may be the root cause of some mental illnesses like some forms of schizophrenia. This is especially applicable to “concretization” of the mind and other wrong associations with schizophrenia. Researching sense of humor may be important for development of treatments for such pathologies.
Methods of testing the conjecture
The author proposed the following methods of testing the main conjecture (note that all these methods may provide only circumstantial evidence, the possibility to research direct proofs is not yet established).
Using amusing gas
Because the amusing gas has a similar to activation of sense of humor effect to a human, in the framework of the main conjecture it supposed to be feasible that the amusing gas blocks creation of associations.
I propose computer tomography of people under influence of the amusing gas (and a control group) for investigating whether the amusing gas blocks forming associations.
Direct scanning of the brain
I propose a two-stages experiment.
At the first stage by scanning the brain identify the zones of the brain which are activated when forming (non-humorous) associations, proposing to the examinee pairs of associations (during computer testing associations).
At the second stage, activating the sense of humor check whether activation of these brain zones ceases, when offering him pairs of associations. There two variants of this (second) stage: Either the sense of humor activates by offering comical pairs of associations, or there are offered associations similar to the first stage (that is non comical associations).
The author realized that at the modern level of technology development the testing may be quite imprecise.
 Freud Z. Wit and his attitude to the unconscious. M., 1924
 M. Choici. “Fear of laughter”
 Henri Bergson “Laughter. The essay on the essence of the comic “
 Krishtafov I. A. “Theory of Humor”
 Geoffrey Miller. The Mating Mind: How Sexual Choice Shaped the Evolution of Human Nature, 2000