President Trump arrives to speak at the Conservative Political Action Conference in Oxon Hill, Md., on March 2. (Carolyn Kaster/AP)

On Jan. 8, President Trump delivered a nationally televised speech calling again for a wall along the U.S.-Mexico border. He said:

America proudly welcomes millions of lawful immigrants who enrich our society and contribute to our nation. But all Americans are hurt by uncontrolled illegal migration. It strains public resources and drives down jobs and wages. Among those hardest hit are African Americans and Hispanic Americans. Our southern border is a pipeline for vast quantities of illegal drugs, including meth, heroin, cocaine and fentanyl.

That same evening, newly elected Rep. Alexandria Ocasio-Cortez (D-N.Y.) appeared on “The Rachel Maddow Show” to rebut Trump’s speech. She said:

Every day, immigrants commit crimes at a far lower rate than native-born Americans. And not only that, but the women and children on that border that are trying to seek refuge and seek opportunity in the United States of America with nothing but the shirt on their backs are acting more American than any person who seeks to keep them out ever will be.

Trump and Ocasio-Cortez were not only staking out different positions, they were speaking in different styles. Based on word length and sentence length, Ocasio-Cortez’s interview was more linguistically complex than Trump’s speech.

This is not a fluke. As earlier findings indicate, our research shows that politicians from socially liberal parties use more complex language than politicians from socially conservative parties.

Here’s how we did our research

We analyzed 381,609 speeches delivered by politicians from Germany, the Netherlands, Spain, Sweden and the United Kingdom. These speeches include not only those of 12 prime ministers but also those given in these countries’ parliaments and party congresses.

We used an automated method that evaluated each speech using the Flesch-Kincaid test. This measure was initially developed by education researchers to score readability of a text, expressed as the years of schooling required to understand a given text without difficulty. It is based on the average number of words per sentence and the average word length. Higher Flesch-Kincaid scores correspond to higher complexity because of longer words, longer sentences, or both.

The graph below presents average complexity scores for a number of selected leaders. Prime Minister Gordon Brown, a liberal, gave speeches with higher complexity scores than his successor David Cameron, a conservative.


Average verbal complexity scores for a selected list of political leaders. (Bert N. Bakker/Bert N. Bakker)

Here’s an example

For instance, here’s how the liberal Brown spoke about the “Make Poverty History” campaign:

And I believe that no injustice will last forever, so people who are oppressed need not any longer journey without hope. And with this most powerful peaceful weapon for change: of conscience linked to conscience — people with a shared moral sense and a capacity to communicate and organize; and the power that comes from calling, networking, marching for change, millions can now be moved to action — as with Make Poverty History — against the great injustices of poverty, disease and environmental degradation.

And here’s the conservative Cameron, discussing the same issue:

Some people thought it might only benefit those buying relatively expensive properties. Again, that’s not the case. The typical property being bought under this scheme is around the average house price in the UK. So this is a successful scheme. Those are the numbers, but this is about more than numbers. It’s about hard-working people achieving their dream of homeownership.

Brown’s text is linguistically much more complex (a Flesch-Kincaid score of 19.5) than that of Cameron (a score of 7).

The same was true in other countries, too. In Spain, the speeches of the liberal former prime minister José Zapatero are more complex than those of his successor, the conservative Mariano Rajoy. Similarly, the speeches of two other liberal politicians, Joschka Fischer of the German Green Party and Nick Clegg of the British Liberal Democrats, were more complex than those of Geert Wilders, leader of the far-right Freedom Party in the Netherlands, and Jimmie Åkesson, leader of the far-right Sweden Democrats. Such differences emerged in different time periods and countries, and when politicians were speaking to different kinds of audiences.

We also found that the differences between liberal and conservative politicians involve social issues more than economic issues. Politicians with liberal and conservative views of economic issues were not nearly as different in their language use as those with liberal and conservative views on issues such as immigration and law and order.

But why do liberals and conservatives tend to speak differently?

One possible explanation is personality. Dana Carney and her colleagues find that liberals tend to be more open-minded, creative and curious, while conservatives tend to be more orderly, conventional and organized. As a result, conservatives may prefer shorter, simpler language, while liberals prefer language that is more ambiguous or engages multiple angles of an argument, leading to more complexity.

What our research can’t address is whether simple or complex language is more useful for politicians. Simpler language could resonate with the public — and certainly many memorable political statements are simply put, such as Barack Obama’s “Yes, we can” or Ronald Reagan’s “Tear down this wall.” On the other hand, it’s apparent that neither liberal nor conservative parties have a monopoly on winning, suggesting that the simplicity or complexity of language offers no consistent political payoff.

Martijn Schoonvelde (@hjms) is assistant professor of political science at University College in Dublin.

Anna Brosius (@annabrosius) is a PhD candidate at the Amsterdam School of Communication Research at the University of Amsterdam.

Gijs Schumacher (@gijsschumacher) is associate professor of political science at the University of Amsterdam.

Bert N. Bakker (@bnbakker) is assistant professor of political communication at the University of Amsterdam.