The Trump-Harris debate shows how personality can reveal itself in language

An analysis of the choice of words by American presidential candidates Kamala Harris and Donald Trump in their recent debate reveals five insights into their personalities.

First, my co-author and I found that Trump made more self-references than Harris, whereas Harris referred more to others than Trump did. Trump also did not say “Kamala” or “Harris” even once, suggesting an attempt to anonymize the vice president.

Second, both candidates equally emphasized geopolitics, mentioning Russia, Israel, Ukraine and Iran. However, neither mentioned Palestine.

Third, Trump used slightly more words that indicated uncertainty than Harris did.

Fourth, Trump used more achievement-oriented words, whereas Harris used more that suggested affiliation and power.

Fifth, Harris focused more on the country’s present state, whereas Trump emphasized the past and the future.

Focusing on words

The theory of psycholinguistics suggests that a person’s personality is revealed in their choice of words . That can mean that when an audience seeks information about people, they often rely on their choice of words and, equally importantly, words they don’t use.

When speakers want to persuade a listener, they strategically choose some words and avoid others .

The same concept applies to candidates and voters during an election campaign.

Read more: How Kamala Harris won the U.S. presidential debate against Donald Trump

We used theories in psycholinguistics and computational linguistics to analyze the two candidates’ choices of words and discover some psychological indicators that may help voters make sense of what was said “between the lines.”

These data-driven insights could be useful for undecided voters, particularly in the swing states of Pennsylvania, Georgia, North Carolina, Michigan, Arizona, Wisconsin and Nevada.

They could also be useful for decided voters, either as confirming their prior views on the two candidates or altering their opinions on what they already know about the candidates.

Data source and analysis method

We downloaded the debate transcript data from ABC News .

Next, we developed a program using Python — a computer programming language — to separate the debate transcript into speaking turns. For example, Harris took the first turn to speak, followed by Trump, and next Harris, and so on. Therefore, our data file allowed us to decompose the debate into “speech acts,” where each act is a candidate’s turn to speak.

We entered this data file to a text analysis software program that helped us measure each speech act on four psychological variables:

1. Self-referencing, opponent reference and third-party referencing;

2. Geopolitical wars;

3. Uncertainty;

4. Candidate’s motivations;

5. Temporal focus.

A key distinguishing feature in leaders’ speeches is how much they focus on themselves versus others . Self-referencing is usually related to hubris, overconfidence or outright narcissism. In contrast, referencing others suggests the speaker is communicating with the other party as opposed to reciting prepared remarks. Therefore, we next measured each candidate’s speech act on self-referencing, opponent referencing and other-referencing.

1. Referencing

Trump tended to focus more on himself as reflected by his higher use of the word “I.” In contrast, Harris used “we” more frequently, signaling a focus on collective responsibility. This asymmetry indicates that Trump centered more on individual agency, while Harris leaned towards a more group-oriented approach.

Harris often addressed Trump directly, which suggests she intended to engage him in a more personal and direct conversation. In contrast, Trump avoided directly addressing Harris, instead using third-person references or speaking more broadly to the audience. Interestingly, in the Trump-Biden debate on June 27, 2024, Trump said “Biden” twice and “Joe” thrice.

Trump’s speech indicates that he “anonymized” Harris, distancing himself from directly confronting her, while Harris sought a direct exchange. The debate dynamics reflect Harris’s intent to engage Trump personally, while Trump sidestepped this engagement in favour of more generalized discourse.

2. Geopolitical wars

This presidential election campaign has been affected by geopolitical instability via the Russia-Ukraine and Israel-Hamas wars. Therefore, we measured how often the candidates mentioned the geopolitical wars.

Trump mentioned war and conflict-related topics far more frequently than Harris, indicating that he placed a stronger emphasis on discussing military and conflict issues during the debate.

Trump also referred to Russia more often than Harris, suggesting a greater focus on geopolitical matters concerning Russia. However, both candidates discussed Ukraine at similar levels, indicating a shared interest in the topic.

Both candidates made frequent references to Israel, showing its significance for both. Mentions of Hamas and Iran were relatively low, with Trump bringing up Iran slightly more. Neither candidate mentioned Palestine, suggesting that it was not a key focus for either during the debate.

Read more: The specter of China has edged into US presidential election rhetoric − for Republicans much more than Democrats

3. Uncertainty

Both candidates used tentative language at relatively similar levels, with Trump showing a slightly higher tendency towards uncertainty.

This suggests that while neither candidate was overly hesitant in their statements, Trump exhibited a marginally higher degree of caution or ambiguity in his speech compared to Harris.

4. Motivations

Psychological research suggests people generally have three motivations: affiliation, achievement and power . Therefore, we compared the two candidates’ use of affiliation-oriented words, achievement-oriented words and power-oriented words.

Harris used affiliation-related words more often than Trump, indicating that she referenced group identity or a sense of belonging more frequently than Trump.

Neither candidates mentioned achievement-related terms very often, but Harris did so at a slightly higher level, suggesting a subtle focus on her accomplishments.

Harris also used more power-related words than Trump, suggesting she placed more emphasis on control, authority or influence in her speech.

5. Focus: Past, present or future

Trump exhibited a stronger focus on past and future contexts, frequently referencing previous accomplishments and future plans, while Harris concentrated more on present issues, emphasizing ongoing challenges and current actions.

This distinction suggests that Trump tends to frame his narrative around what he has done and what he will do, while Harris centres her arguments around what is happening now and immediate needs.

Persuading others

Communicators use language to sway others, particularly during elections when each candidate aims to persuade undecided voters to cast their ballots for them while strengthening the opinions of committed voters.

Language can also help reveal the communicator’s personality traits and help voters weigh evidence on which candidate aligns with their interests and values.

Qianhui Liu, an undergraduate student at McGill University in Economics and Finance, co-authored this article .

Vivek Astvansh does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.