Dear caramel3536,

Great question! But I really don't have a clear cut answer, unfortunately. Using contractions does give the essays a more informal tone, but that is not necessarily a bad thing. I'm sure there are some schools, or more likely some admissions committee members, who prefer you not use contractions. Whether that should influence you is really your decision. It is a personal preference and so you have to go the way you feel is best.

Good luck,
Lisa