US politicians use moral language more often when they have less power

Whatever your political affiliation, making appeals to people's morality can be a powerful rhetorical tool.

Politicians frequently use language that refers to moral principles of harm, fairness, loyalty, authority and purity, in order to defend policy positions, appeal to new voters and appease old ones. And it's an approach that seems to work.

Research suggests that people are far more likely to take action once they connect a particular issue with their own moral or ethical convictions — even to the point of committing acts of violence.

But how and when politicians use moral language shifts with changes in the political landscape, according to a new study from the University of Toronto's Sze-Yuh Nina Wang and Yoel Inbar, published in Psychological Science. Looking at Democrat and Republican politicians in the US, they found that moral language increased as political power decreased, suggesting that its use is not fixed. 

The first study looked at public tweets posted by members of the Senate and the House of Representatives; some, like Vermont senator Bernie Sanders, had millions of followers, while others had thousands. Using a text-analysis technique, the team coded nearly 700,000 tweets posted between January 2016 and January 2018 from 578 politicians in Congress (385,206 from Democrats and 302,154 from Republicans).

The team focused on five moral foundations — harm, fairness, loyalty, authority and purity — and their positive and negative aspects ("virtues" and "vices"). For the analysis, the tweets were compared to a dictionary containing words related to each virtue and vice, to see how close the language in each tweet was to these words.

Overall, Democrats used moral language more frequently than Republicans. And while moral language was used more by both parties after the 2016 Presidential election, this increase was greater for Democrats, who were more likely to go on using moral language. This was also the case for those moral foundations more traditionally associated with Republicans (loyalty, authority and purity).

A second study looked at transcripts of all debates and proceedings in Congress between 1981 and 2017, utilising the same text-analysis technique as in the first study.

In both the House and the Senate, the minority party was far more likely to use moral language related to almost all of the foundations (a notable exception was language related to authority, which was sometimes used more frequently by the majority party).

Overall, the results suggest that the use of moral language is dynamic rather than static, and likely to change over time depending on context. This makes sense — moral language is often ramped up during national crises, perhaps because there is more at stake.

Future research could look at what subjects are being discussed using moral language — is it being used on specific issues, or more broadly to condemn the opposing party? Who is using such language also seems relevant.

There are a huge range of divergent views even within a political party itself — a left wing politician like Bernie Sanders or Ilhan Omar is unlikely to share the exact moral values of the more centrist Nancy Pelosi, for example, even though they all belong to the Democratic Party.

Further reading

– Moral-Language Use by U.S. Political Elites

About the author

Emily Reynolds is a staff writer at BPS Research Digest