The final debate of the 2016 presidential election is fast approaching. Over the past month, politicians and pundits have repeatedly called these debates

unprecedented and abnormal

and we wanted to crunch the numbers to find out if that's actually the case. To do that, we needed to dig into the last four decades of presidential debates.

We gathered transcripts from every presidential debate of the last 36 years and, after distilling them and applying Scripted's natural language processing tools, built a comprehensive comparison to show shifts and trends in language style over the course of nine elections. From Reagan vs. Carter to Clinton vs. Trump, have the debates really changed that much?

We used a

standardized source

of transcripts and selected the first debate from each cycle - with the exception of the 1980 election, in which Carter and Reagan didn't face off until the third presidential debate. Another outlier was the 1992 debate, which included third party candidate Ross Perot. We chose 1980 as the starting year because that was the first year that debates became a standard part of the presidential election process.

We were most interested in mapping consistent trends in presidential debates over many years. What have been the major topics that mattered to voters, in the eyes of candidates and strategy teams? How has the language spoken to a changing America evolved in the last 36 years? Were there gradual shifts or wild fluctuations depending on the election and/or party affiliation?

Results

Since 1980, presidential candidates have made more and more subjective statements (I think, I believe) during their debates. Subjective statements tend to perform on a more emotional level, so it implies that politicians changed their strategy to aim for voters' hearts rather than their minds. Unlike some other metrics, it's also a trend that's visible for both parties at approximately the same rate over time.

Highlight: Before and including 1988, the less subjective candidates won. Afterwards (with the exception of 2012) the more subjective have come out on top.

Politicians' use of positive vs. negative language has varied a lot over time, but the general trend since 1980 has been towards a more uplifting spin. Leaving the Cold War era, into the profitable 90's, and through the market crash of the mid-2000's, positivity tracks with national sentiments and fears.

Highlight: In most years, the major party candidate (ruling out third party candidates) candidate that used more positive language in their first debate ended up winning the elections. The only exceptions to this trend were 1980 and 2004.

Starting with positively academic language in the 1980 Reagan vs. Carter debate, the trend in grade level generally moved downhill, culminating with the lowest grade level yet recorded during this year's presidential debates.

Highlight: Except for the 1984 debate, Democrat candidates have held a higher grade level standard in their first debate language than Republican candidates.

For most of the last 36 years, the repetitiveness of the speech used by candidates in their debates remained nearly constant, and neither Republicans nor Democrats had a monopoly on varied speech.

Highlight: Republican and Democratic candidates experienced an ever-increasing gap in repetitive language, starting with the 2004 election, with Democrats using less and Republicans using more during the first debate.

Prevailing topics in American presidential debates have been the economy (tax cuts, social security, middle class), foreign relations (North Korea, Saddam Hussein), and national security (nuclear weapons). Most major topics have been cyclical, returning to the fore every few elections.



Highlight: The 2000 "social security" craze, followed by eight years of silence on the issue, and the continuously effective use of "tax cut" as a voting motivator.

Scripted's Presidential Debate Analysis is a joint effort between Boris Vassilev and Ryan Fauver