A research article back in 2005 published in 'Applied Cognitive Psychology', proved that writing copy using big words and complicated sentences, in an attempt to appear clever, had the reverse effect. Readers felt that the flowery copy made the author appear less clever. In the words of the article, researchers found a “negative relationship between complexity and judged intelligence.”
However, that's my paraphrasing of the article. The funny thing is, it's written in extremely impenetrable academic prose. The piece carries the title: Consequences of erudite vernacular utilized irrespective of necessity: problems with using long words needlessly
This reminds of the quote by Carol Worthington-Levy, from a previous Knowledge Hub posting:
"Making obscure references may make you feel smart but it makes them feel stupid and that’s a bad place to take a potential customer. "