People who use long words to appear intelligent to others fool themselves but not their audience. That finding gave Daniel Oppenheimer of Princeton University the 2006 IgNobel Prize for Literature.
Sounds reasonable to me. I wish I could reproduce some of the finer examples of meaningless verbosity that I've received from colleagues. But, you know, that wouldn't be very nice.
Oppenheimer not only looked at the complexity of the text but also at its presentation. Typeface made a difference to the way in which the reader perceived the author. So did the amount of toner in the printer. Choice of font had an expected effect—people who use fancy, difficult-to-read fonts are nitwits. The impact of low toner was not quite so predictable. Readers (over-)compensated for it and rated the authors of the near-illegible pieces as more intelligent than those of the cleanly-printed work.
So forget all the highfalutin words next time you want to impress your audience. Just print out your work on a machine with a dodgy toner cartridge. You know it makes sense.
Oppenheimer, D.M. (2006) Consequences of erudite vernacular utilized irrespective of necessity: problems with using long words needlessly. Applied Cognitive Psychology 20 (2): 139–156.