Keep it simple; appear smarter
One of the tips I give to those who wish to improve their writing is to aim for an 8th grade reading level. My goal is clarity.
But there are other reasons to keep things short and simple. Apparently, there is evidence to support the idea that the longer the words you use, the less intelligent the reader will perceive. Check out Long Words Make you Look Stupid at Manage Your Writing. A study revealed that as readers read written passages, and rated the competence of the writer, as “complexity increased, the judges' estimation of the author's intelligence declined."
Hat tip to the Legal Writing Prof Blog.