Not just humor, but the overall tone of your application essay is remarkably important. It's also difficult to get right. When you are asked to write about your accomplishments, those 750 words on how great you are can make you sound like a braggart. Be careful to balance your pride in your achievements with humility and generosity towards others. You also want to avoid sounding like a whiner -- use your essay to show off your skills, not to explain the injustices that lead to your low math score or failure to graduate #1 in your class.
The idea for the joint textbook of historical narratives grew out of the knowledge that in periods of intractable conflicts, nations tend to teach their children their own narratives (often through the vehicle of textbooks) as the only correct one, while completely ignoring their enemy's narratives. If they do include the enemy narrative, it is always presented as being wrong and unjustifiable. These textbooks, which also include [nation-legitimized knowledge, convince children that there is a necessity to continue to dehumanize the enemy, and this leads to the development of negative attitudes and values toward the other. This state of affairs is very clear in the Palestinian-Israeli situation and has been studied in the joint research of Palestinian and Israeli history textbooks undertaken by Firer (an Israeli) & Adwan (a Palestinian).