A Scientific Formular for Humour :

HE = PI x C/T + BM

Where:
HE = Humor Effectiveness.
PI = Personal Involvement
C = Complexity of a joke.
The higher degree of complexity the easier it will be
for your audience to solve the problem within 1 or 2 seconds.

T = Time spent by a person solving the joke.
The longer the time, the weaker the effect.

BM = Background Mood.
The joker has an advantage if an audience is enjoying the show.
However, a really good joke can liven up the most dismal audience.

~

U.S. scientist Igor Krishtafovich discovered the above formula of laughter.
He came to back Moscow to spread the formula among his former compatriots.

As it turned out, humor is a weapon.
Igor Krishtafovich is confident that humor always implies aggression.
"It is a bloodless verbal fight aiming to raise your status and strengthen
your position. Even a friendly banter is a sort of intellectual clash, a kind
of training before serious battles. In fact, some families try to figure out
who's the boss by poking fun at loved ones," says Mr. Krishtafovich.
A sense of humor is a strong male quality. It is a sign of good intellect.
Survival relies on the intellect since a smart fellow has more chances
of survival. That is why a sense of humor can be a much bigger sign of
masculinity than the pumped-up muscles. Needless to say, I'm talking
about the subconscious level of perception."

adapted from an article at:
http://english.pravda.ru/
Science and Health, Discoveries.