The Tendentious joke (n.) rebels against propriety by giving vent to libidinal impulses of violent aggression and sexual desire while an innocent joke rebels against reason with word play and nonsense.
A Tendentious joke (n.) is a mechanism for expelling tension through laughter that avoids the censorship of the super-ego, which can be equated with social censorship.
The Tendentious joke (n.) is either hostile (used to attack) or obscene.
The Tendentious joke (n.) serves an aim — hostility or exposure — and only such jokes risk meeting people who do not want to hear them; the others are innocent.
The Tendentious joke (n.) needs three people: the teller, the victim, and the listener — and it is the listener, not the teller, who laughs.
The Tendentious joke (n.) bribes the hearer with pleasure into taking our side without looking too closely — it brings the laughers over to us.