We've often accused people who use needlessly complicated language of trying to appear intelligent (at the expense of clarity). But according to a leading American university, they may be failing in such an aim.

The Stanford University study says people who use complicated language when simple words will do tend to be viewed as less intelligent than those who use a more basic and understandable vocabulary. The study found this applied even to 'academic' writing such as postgraduate applications, sociology dissertations and translations of the philosopher Descarte's writings.

"I think it's important to point out that this study is not about problems with using long words, it's about problems with using long words needlessly," lead study author Daniel Oppenheimer explained to the Reuters news agency. "If the best way to say something involves using a complex word, then by all means do so. But if there are several equally valid ways of expressing your ideas, you should go with the simpler one."

He added that most writers were unaware that readers judged intelligence in this way. He gave the example of college applicants adding complicated language to application essays to impress the reviewers. If the school rejects their application as a result of the heavy-handed writing, the student may not realize why. "The student might even think that the reason was because he or she didn't obfuscate enough."