TV Dick Part 3: Those Jews!
Though I can't cite every example I've heard, circumcision jokes are fairly popular on TV sitcoms. Circumcision jokes are usually based around a Jewish character and the joke is made as if circumcision is solely unique to Jews. There have been several circumcision jokes made on the Big Bang Theory because the character Howard is Jewish. But odds are good that Sheldon and Leonard would be circumcised, too. In America circumcision is far from exclusively Jewish. Even in these more enlightened times when many parents choose to not have their boys circumcised America's non-religious circumcision rate is pretty high. Growing up in the 70s I had one friend who wasn't circumcised and can't recall seeing a single uncircumcised penis in my gym class showers. All my male friends, none of them Jewish or Muslim (a group that never is included in the circumcision jokes), were/are circumcised. Almost every guy I've ever fooled around with has been circumcised