Trump’s Cognitive Decline is Obvious

Words. Words are what I know how to do things with. So I decided to do some things with words. And I have to tell you, I was really surprised and dismayed by what I learned.

Claims are flying that Presiden Biden is incompetent, not fit to finish his term, much less serve for another four years. But what of former president Trump? He’s been called a danger to democracy, unfit to rule — but on account of his character, but not his cognitive state.

I got curious. I pulled an interview Trump gave in 1980 as a baseline, and I compared that with two speeches and an interview from the past decade: 

• October, 1980, interview with Rona Barrett
• October, 2017, speech at the Heritage Foundation
• April, 2023 interview with Time Magazine
• July, 2024 speech at the Republican National Convention

Speech analysis provides a good window into cognition. More sophisticated speakers use a wide vocabulary and complex sentence structures that reflect depth, breadth, and subtlety in thought. Cognitive decline is accompanied by a decrease in these metrics, pointing to shrinking capacity for attention to complicated issues. Like, for example, international politics.

For the purpose of this analysis, I used online text analysis tools that count the number of words in each sentence, as well as the number of unique words in each passage. As a proxy for word complexity, they calculate the average number letters and syllables per word, and compare words used against a list known to most fourth graders in a study done in 1984.

They crunch the numbers using several different formulas, whose results are usually expressed as a number corresponding to a grade level. If the text is assigned a 10, it means the average tenth grader will understand it easily.

I pasted excerpts from each of Trump’s speeches and interviews into two different online text analysis tools (in case programming details produced different results; they didn’t), and I averaged the results produced by four formulas.

In the 1980 interview, Trump spoke at a grade level of 10.5, averaging 20 words per sentence. In the 2017 speech, this went down to grade 9, and 12.5 words per sentence. Sentence length in the 2023 interview was comparable at 12.9, but the grade level slipped again, to 7.4.

In his convention speech this month, Trump averaged 9.4 words per sentence at a grade level of 5.9.

For context and comparison, in a 2023 speech at Fisk University, Vice President Harris averaged 23.5 words per sentence and spoke at a grade level of 11.3. In his comments on the RNC shooting, President Biden used 14 words per sentence on average, at a grade level of 10.8.

Given the evidence of Trump’s speech over the years, he is clearly unfit to serve another term as president, not only on grounds of the threat he and his associates pose to democracy, but also because of the decline in his cognitive abilities.