Over at Vocativ, EJ Fox, Mike Spies, and Matan Gilat have a fascinating analysis of how the type of language used in presidential speeches has changed over time. They collected the text of over 600 presidential speeches starting with George Washington, and used the Flesch-Kincaid readability test to rate the complexity of each speech's language. Each speech got a grade level rating — a rating of "four" is a speech a fourth-grader could understand, while "15" would be a college graduate, and "21" a PhD student. Overall, the authors found a marked decline in complexity over the past two centuries:
Now, it's important to note that speeches using more complex words and language aren't necessarily better. Indeed, the whole point of this rating scale is that the higher your speech scores, the fewer people understand what you're talking about. Simplicity in language and word choice can often help a message be communicated effectively and powerfully, to an audience of people from many different backgrounds — and that's just what modern presidents and their speechwriters are trying to do. Head over to Vocativ for the full analysis, with commentary from former Bill Clinton speechwriter Jeff Shesol, and a hat tip to Jason Kottke for flagging it.