No matter what tone you choose for your essay, keep four general rules in mind:
Be consistent. Adopt a tone and stay with it.
Select a tone that is appropriate for your purpose. For example, in a discussion about the traumatic effects of a death in your family, a casual or chatty tone would sound out of place.
Be aware of your audience. The readers are educated adults who have waded through hundreds of applications essays. Be attuned to their feelings and experience. Generally speaking, avoid extremes: don’t be overly aggressive, arrogant, obsequious, didactic, sentimental, etc. As you write, try seeing your essay as the admissions readers might view it.
Be yourself. Any attempt to paint an unnatural picture of who you are will ultimately fail.
WARNING! Perhaps the greatest menace to developing an effective tone is the desire to sound overly intellectual. Essay writers who want to impress readers with their intelligence frequently end up with writing that is cluttered, tangled, hard-to-follow, and unnatural. To the readers, this kind of posturing ends up sounding pompous. Pompous prose is writing that is often ostentatious, fake, stilted, and unnaturally puffed up. In other words, it is writing that presents an artificial tone. Franklin D. Roosevelt, a writer who understood the charm of uncomplicated writing, balked at a particularly pompous memo dealing with air raids:
"Such preparations shall be made as will completely obscure all Federal buildings and non-Federal buildings occupied by the Federal Government during an air raid for any period of time from visibility by reason of internal or external illumination. Such obscuration may be obtained either by blackout construction or by termination of the illumination."
F.D.R. rewrote the memo and in the process “depuffed” it:
"Tell them that in buildings where they have to keep the work going to put something over the windows; and, in the buildings where they can let the work stop for a while, turn out the lights."
The pompous writer incorrectly assumes that admission readers will be impressed with “elegant” or “scholarly” writing. As a result, he marches a whole parade of big words across the page and he takes ordinary ideas and dresses them up in grandiose diction. Consider the following puffed up sentence:
"Only through extended verbal contact can an individual efficaciously eradicate the fears that invariably manifest themselves during such an encounter."
Ideas presented with accurate, sincere words are much more impressive than ideas packaged in the wrappings of a counterfeit vocabulary. Of course, a big word used appropriately is not bad, but big words used for the sake of using big words will alienate a reader. Admission readers want to hear the intelligent you, not some forced pseudo-intellectual voice.