Daniel Kahneman sets them straight in Thinking, Fast and Slow: ‘If you care about being thought credible and intelligent, do not use complex language where simpler language will do. My Princeton colleague Danny Oppenheimer refuted a myth prevalent among undergraduates about the vocabulary that professors find most impressive. In an article titled “Consequences of Erudite Vernacular Utilized Irrespective of Necessity: Problems with Using Long Words Needlessly”, he showed the couching familiar ideas in pretentious language is taken as a sign of poor intelligence and low credibility.
Excerpt from: How To Write Better Copy (How To: Academy) by Steve Harrison