Bop on the Head

The Japanese will sometimes playfully "bop" eachother on the head during discussions. After witnessing this in several situations, I wish to classify and justify the appropriate times in which the "bop on the head" may be administered. There seem to be 2 general rules that all successful "bop-happenings" adhere to. Notice that the "bop" is an exchange and therefore exhibits communicative dialogue.

• The bop must be administered in a playful, surprising, and timely fashion.
• The recipient of the bop is not allowed to duck or dodge.

So with these 2 general rules explained, let's explore the matter more deeply. Bops are frequently given for some sort of unexpected, somewhat ignorant statement. The "bop" takes on a intended meaning of 'use your head.' Hence, the bop must be quickly administered. However, in the best "bopping" situations, there seems to be a humorous quality to the mistake; thus, the "bop" is an extension of the humor. The recipient plays a straight-man role like Tommy Smothers, the genius behind most of the skits on the highly controversial Smother's Brothers who played the good-intentioned idiot of the show. Much the same with the best "bops." The ricipient makes a comment worthy of being hit on the head for, but in a good natured fashion. Hence the unexpected and playful natures of the "bop" come from the recipient. The ricipient cannot dodge the bop because that would show the intention of the comment. Instead, like those around watching the interaction (for "bops" happen in real life) the ricipient must be as un-assuming as the audience.

Perhaps this has been to short and assumptive. Oh well, here are some examples of successfull "bopings".

• Bopping the Japanese-fluent foreigner on live television! By far the most successfull bop I've seen. Take into consideration that foreigners in Japan are usually given a certain amount of forgiveness. There is an attitude that we don't know any better. So, the unexpected nature of such a "BOP" is outstanding! My jaw dropped. I waited to see the white guy turn around and slug him... Instead, my shock became incredible laughter.
• The Teacher to Student Bop Wow, would this be a serious offense in the United States or what? My example lies in a private team-teacher session. At the start of the session the Japanese student responded to a question in English with a joke in Japanese. It was funny enough to evoke the "don't get off topic bop." The teacher and student were laughing and I, well, I was a bit aghast at my first "bop" experience.
• The bus-bop group Teenage boys being somewhat of dunces throughout the world, I enjoyed seeing a round robin of bops between about 7 boys. The reason for the bops was disagreement on the originals statements truth and the bop itself.

QUESTIONS: Anyone know what the Japanese refer to the "bop" as?