Trump's simple language fits long-term political trend

US President Donald Trump language, perceived by many as unconventional, is actually similar to the simple, straightforward speeches of the past and present world leaders that exudes confidence, a study has found.

The research, published in the journal Proceedings of the National Academy of Sciences, suggests that the recipe that likely helped Trump become a successful presidential candidate was set in motion almost 100 years ago.

"The findings confirm that President Trump and leaders like him did not emerge out of nowhere, but rather are the most recent incarnation of long-term political trends," said Jamie Pennebaker, a professor at University of Texas at Austin in the US.

"Taken together, the trends suggest that voters may increasingly be drawn to leaders who can make difficult, complex problems easier to understand with intuitive, confident answers," Pennebaker said.

For linguists, function words -- such as prepositions, pronouns and conjunctions -- say a lot about how people think.

Prior research has linked high rates of pronouns, negations and auxiliary verbs to low analytic, or more intuitive, thinking. The heavy use of the pronouns "you" and "we" has been shown to indicate higher status, confidence or clout than the use of impersonal pronouns or "I" and "me."

Using the text analysis programmes, researchers measured the evolution of analytic thinking and clout in presidential language since 1789, focusing on the use of function words in past inaugural addresses, public papers, debates and speeches.

Researchers found that analytic thinking remained high throughout the 18th and 19th centuries but began declining around the time of Woodrow Wilson's presidency.

By the time Dwight Eisenhower took office in the 1950s, presidential language had struck a new tone of confidence. Mapping this, researchers determined Trump only deviated from the trend in one setting -- debates, where his speech was less analytic than that of any previous president.

"Donald Trump was, by and large, not an outlier, psychometrically speaking," said Kayla Jordan, a psychology doctoral candidate at UT Austin.

"These results strongly suggest that the recipe that likely helped Trump become a successful presidential candidate was set in motion almost 100 years ago," said Jordan.

Researchers also examined the language of other English-speaking world leaders. They found that low analytic thinking and high clout have also become more common in Canada and Australia.

British leaders have maintained higher analytic measures, but evidence shows their language, too, has begun to convey more confidence.

Although these trends are similar to those seen in the US, they developed later, around the 1980s, researcher said.

"The results from non-American leaders provide evidence that the simple, confident rhetorical style observed in recent American presidents is an increasingly important marker of leadership globally," said Ryan Boyd, a postdoctoral researcher at UT Austin.