Robin adds the recent theory that humor arises from benign norm violations to his Homo Hypocritus model:

The Homo Hypocritus (i.e., man the sly rule bender) hypothesis I’ve been exploring lately is that humans evolved to appear to follow norms, while covertly coordinating to violate norms when mutually advantageous. A dramatic example of this seems to be the sheer joy and release we feel when we together accept particular norm violations.  Apparently much “humor” is exactly this sort of joy:

[The paper:]The benign-violation [= humor] hypothesis suggests that three conditions are jointly necessary and sufficient for eliciting humor: A situation must be appraised as a [norm] violation, a situation must be appraised as benign, and these two appraisals must occur simultaneously.will be amused. Those who do not simultaneously see both interpretations will not be amused.

In five experimental studies, … we found that benign moral violations tend to elicit laughter (Study 1), behavioral displays of amusement (Study 2), and mixed emotions of amusement and disgust (Studies 3–5). Moral violations are amusing when another norm suggests that the behavior is acceptable (Studies 2 and 3), when one is weakly committed to the violated norm (Study 4), or when one feels psychologically distant from the violation (Study 5). …

We investigated the benign-violation hypothesis in the domain of moral violations. The hypothesis, however, appears to explain humor across a range of domains, including tickling, teasing, slapstick, and puns. (more;HT)

[Robin:] Laughing at the same humor helps us coordinate with close associates on what norms we expect to violate together (and when and how). This may be why it is more important to us that close associates share our sense of humor, than our food or clothing tastes, and why humor tastes vary so much from group to group.

I disagree with the theory and with Robin’s take on it.

Benign social norm violations are often not funny:

Yesterday I drove home drunk, but there was almost nobody out that late anyway.

Some people tell small lies in job interviews.

You got his name wrong, but I don’t think he noticed

Things are often funny without being norm violations:

People we don’t sympathize with falling over, being fat, being ugly, making mistakes, having stupid beliefs

People trying to gain status we think they don’t deserve and failing (note that it is their failure that is funny, not their norm-violating arrogance) or acting as though they have status when they are being made fools of really

Silly things being treated as though they are dangerous or important e.g. Monty Python’s killer rabbit, and the board game Munchkin’s ‘boots of but kicking’ and most of its other jokes

Note that the first two are cases of people we don’t sympathize with having their status lowered, and the third signifies someone acting as if they are inferior to the point of absurdity. Social norm violation often involves someone’s status being lowered, either the norm violating party if they fail or whoever they are committing a violation against. And when people or groups we dislike lose status, this is benign to us. So benign norm violations often coincide with people we don’t care for losing status. There are varieties of benign violation where we are not harmed but where nobody else we know of or dislike loses status,  and these don’t seem to be funny. All of the un-funny social norm violations I mentioned first are like this. So I think ‘status lowering of those we don’t care for’ is more promising a commonality than ‘benign norm violations’.

I don’t think the benign norm violation view of humor is much use in the Homo Hypocritus model for three reasons. Humor can’t easily allow people to agree on what norms to violate since a violation’s being benign is often a result of the joke being about a distant story that can’t affect you, rather than closely linked to the nature of the transgression. Think of baby in the blender jokes. More likely it helps to coordinate who to transgress against. If I hear people laughing at a political leader portrayed doing a silly dance I infer much more confidently that they don’t respect the political leader than that they would be happy to do silly dances with me in future.

Second, if it were the case that humor was a signal between people about what norms to violate, you would not need to get the humor to get the message, so the enjoyment seems redundant. You don’t have to find a joke amusing to see what norm is violated in it, especially if you are the party who likes the norm and would like to prevent conspiracies to undermine it. So this theory doesn’t explain people liking to have similar humor to their friends, nor the wide variety, nor the special emotional response rather than just saying ‘hey, I approve of Irishmen doing silly things, so if you’re Irish we could be silly together later’. You could argue that the emotional response is needed so that the person who makes the joke can judge whether their friends are really loyal to the cause of transgressing this norm, but people laugh at jokes they don’t find that funny all the time.

Last, if you want to conspire to break a social norm together, you would do well to arrange this quietly, not with loud, distinctive cackles.

That said, these are interesting bits of progress, and I don’t have a complete better theory tonight.