Is language dumbing down?

Youth these days

In the media, we can read that political speeches are getting simpler (2013):

This kind of article is typically used to bash the current right-wing president if such exists. E.g., Trump's speeches (2018):

But it is also true that song lyrics are getting simpler (2024):

There's a study from 2020 finding the same result for American music:

This could be taken as a kind of indirect confirmation of declining (verbal) intelligence. But this inference would be unwise because according to this study, here's how it looks like when you look at different kinds of political speeches and writings:

So state of the union speeches got simpler, some of which is just because they are spoken rather than written:

But the other kinds of political writings or speeches did not get simpler. Clearly, things are more complicated than a simple decline narrative.

There are multiple reasons why language in some domain may get simpler in some way. Maybe people have started writing or talking to a broader audience. More people follow politics in modern times than was true 100 years ago, so the audience average intelligence level has necessarily declined (in the same way university students' intelligence has decreased due to greater enrollment). Furthermore, if you have ever read English from the past, you will know that more complex language is not necessarily better. It may be just worse, poorly written, with many inserted clauses (read anything from any German philosopher, or try reading John Stuart Mill, or David Hume).

There exists a variety of indexes to quantify the complexity of language ('readability') based on indicators such as average words per sentence, average word length, and average syllables per word. Some of them show simplifying trends, and others do not. From the same study:

Or various US government writings and speeches (combined index):

If researchers instead has focused on executive orders, they would have concluded that language was getting more complex, as these are apparently getting nearly incomprehensible.

Overall, I find this research interesting, and it should be expanded to more languages and domains (e.g. narrative complexity in movies), but right now, it doesn't support civilizational decline claims.