Q: Why are most Jewish jokes derogatory? My non-Jewish spouse noted, I think correctly, that they often reflect some of the worst stereotypes about Jews (self-serving, in particular). Some characterizations are clownish, and Jews laugh heartily on hearing them.
A: There are several Jewish joke books currently popular which deal with this issue in their introductions. Basically, some of the derogatory jokes in the world of Jewish humor are self-deprecating as a means of dealing with the bitter cruelty of Jewish existence throughout the past centuries until relatively recent times. In other words, it was rage and anger at the outside world turned inward--but purely for internal consumption.
The existence of down-right offensive, anti-semitic jokes, however, stems from bigots and racists who use humor as a means of trying to elicit sympathy for their disgusting views and try to make such bigoted ideas acceptable and even popular by claiming, "it is only a joke."
Many Jews also tend to laugh at such jokes (both kinds) because the overwhelming majority of American Jews are assimilated, ignorant of the Jewish tradition, and have no authentic sense of their own identity. Therefore, this kind of laughter can be seen as either an attempt by these Jews to distance themselves from their own tradition due to their own native sense of alienation, or as an attempt to "fit in" to the larger society and they think that self-deprecation is the means of doing so. Or perhaps, sadly enough, because these Jews are so Jewishly uneducated that they accept the reality of the Jewish stereotypes in the jokes!
Rabbi Daniel Kohn