On occasion, students, in an attempt to appear scholarly, have used vocabulary that comes off as phony. Many times the words used weren't even appropriate to the content of the personal statement. This error is easily spotted and does not lend credibility to your paper.
Although it is important to start to build up your vocabulary, you must understand the meaning and be comfortable using "important" words. I can't stress enough the importance of projecting the real you. Be sincere--speak from the heart with honesty.