There are typically two kinds of arousal theory; one holds that the pleasantness of humor (however conceived) results from some kind of arousal or tension, and the other that it results from some kind of relief from arousal or tension. The latter seem to be more popular; and the most widely known versions of it are Freudian, which, as you might expect, take the arousal or tension to be sexual in some form.
Hobbes is an example of a superiority theorist, with his account in Of Human Nature of sudden glory as the thing that makes us laugh:
For when a jest is broken upon ourselves, or friends of whose dishonour we participate, we never laugh thereat. I may therefore conclude, that the passion of laughter Is nothing else but sudden glory arising from a sudden conception of some eminency in ourselves, by comparison with the infirmity of others, or with our own formerly; for men laugh at the follies of themselves past, when they come suddenly to remembrance, except they bring with them any present dishonour. It is no wonder therefore that men take heinously to be laughed at or derided, that is, triumphed over.
There are two possible kinds of incongruity theory; one could hold that humor consists primarily in incongruity itself or that it consists primarily in the resolution of incongruities. Incongruity-resolution theories seem to be the most widely accepted among cognitive scientists today; they were also the favored approach of Scottish Common Sense philosophers, such as Beattie, whose summary is still quoted:
Laughter arises from the view of two or more inconsistent, unsuitable, or incongruous parts or circumstances, considered as united in one complex object or assemblage, or as acquiring a sort of mutual relation from the peculiar manner in which the mind takes notice of them.
Both arousal and superiority approaches get some plausibility from the fact that so much humor does involve sex, embarrassment, and disparagement; but one of the great advantages of the incongruity approach is that it allows one to take into account the role of fallacies, which Nefsky highlights, whereas the other two don't seem to account for it at all. One can, of course, hold that they have a supplementary role -- Beattie, for instance, recognized that mood and distress could be relevant to humor, and distinguished between two kinds of humor, one of which does involve disparagement. But neither arousal nor superiority approaches seem to get us very far on the logic-play that is involved in so much of humor.
