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.
re: «Over these last several weeks of summer vacation, Nicole has been working, and working some more, on her common application essay. She’s gone back and forth between two ideas, trying to perfect both, hoping that the one she ultimately chooses will best reflect who she is.»
If Nicole can give herself “permission” to spot the deeper, unexpected, but always “there” connection between her two “separate” essays, she’ll see that she can meld them into one self-defining piece of writing of inestimable power and supremely serenity-eliciting satisfaction. You too, for that matter, with your own writing.
What are colleges looking for? People who don’t care what they’re looking for. That’s what the amazing process of writing a college essay is really all about.